Keithley Drivers

Classes:

`Keithley2000`(name, address[, reset])	Driver for the Keithley 2000 multimeter.
`Keithley2400`(name, address, **kwargs)	QCoDeS driver for the Keithley 2400 voltage source.
`Keithley2450`(name, address, **kwargs)	The QCoDeS driver for the Keithley 2450 SMU
`Keithley2450Buffer`(parent, name[, size, style])	Treat the reading buffer as a submodule, similar to Sense and Source
`Keithley2450Sense`(parent, name, proper_function)	The sense module of the Keithley 2450 SMU.
`Keithley2450Source`(parent, name, proper_function)	The source module of the Keithley 2450 SMU.
`Keithley2600MeasurementStatus`(value[, ...])	Keeps track of measurement status.
`Keithley2601B`(name, address, **kwargs)	QCoDeS driver for the Keithley 2601B Source-Meter
`Keithley2602A`(name, address, **kwargs)	QCoDeS driver for the Keithley 2602A Source-Meter
`Keithley2602B`(name, address, **kwargs)	QCoDeS driver for the Keithley 2602B Source-Meter
`Keithley2604B`(name, address, **kwargs)	QCoDeS driver for the Keithley 2604B Source-Meter
`Keithley2611B`(name, address, **kwargs)	QCoDeS driver for the Keithley 2611B Source-Meter
`Keithley2612B`(name, address, **kwargs)	QCoDeS driver for the Keithley 2612B Source-Meter
`Keithley2614B`(name, address, **kwargs)	QCoDeS driver for the Keithley 2614B Source-Meter
`Keithley2634B`(name, address, **kwargs)	QCoDeS driver for the Keithley 2634B Source-Meter
`Keithley2635B`(name, address, **kwargs)	QCoDeS driver for the Keithley 2635B Source-Meter
`Keithley2636B`(name, address, **kwargs)	QCoDeS driver for the Keithley 2636B Source-Meter
`Keithley3706A`(name, address[, terminator])	This is the QCoDeS instrument driver for the Keithley 3706A-SNFP System Switch.
`Keithley6500`(name, address[, reset_device])	Driver for the Keithley 6500 multimeter. Based on the Keithley 2000 driver,
`Keithley7510`(name, address[, terminator])	The QCoDeS driver for the Keithley 7510 DMM
`Keithley7510Buffer`(parent, name[, size, style])	Treat the reading buffer as a submodule, similar to Sense.
`Keithley7510DigitizeSense`(parent, name, ...)	The Digitize sense module of the Keithley 7510 DMM.
`Keithley7510Sense`(parent, name, proper_function)	The sense module of the Keithley 7510 DMM, based on the sense module of Keithley 2450 SMU.
`KeithleyS46`(name, address, **kwargs)
`KeithleyS46RelayLock`(relay_name)	The S46 either has six pole or a four pole relays.

Data:

Keithley26xx

All Keithley 26xx SMUs supported by QCoDeS.

Exceptions:

`Keithley3706AInvalidValue`
`Keithley3706AUnknownOrEmptySlot`
`Keithley6500CommandSetError`
`KeithleyS46LockAcquisitionError`

class qcodes.instrument_drivers.Keithley.Keithley2000(name: str, address: str, reset: bool = False, **kwargs: Any)[source]

Bases: VisaInstrument

Driver for the Keithley 2000 multimeter.

Methods:

`trigger`()
`__del__`()	Close the instrument and remove its instance record.
`__getitem__`(key)	Delegate instrument['name'] to parameter or function 'name'.
`__getstate__`()	Prevent pickling instruments, and give a nice error message.
`__repr__`()	Simplified repr giving just the class and name.
`add_function`(name, **kwargs)	Bind one `Function` to this instrument.
`add_parameter`(name[, parameter_class])	Bind one Parameter to this instrument.
`add_submodule`(name, submodule)	Bind one submodule to this instrument.
`ask`(cmd)	Write a command string to the hardware and return a response.
`ask_raw`(cmd)	Low-level interface to `visa_handle.ask`.
`call`(func_name, *args)	Shortcut for calling a function from its name.
`close`()	Disconnect and irreversibly tear down the instrument.
`close_all`()	Try to close all instruments registered in `_all_instruments` This is handy for use with atexit to ensure that all instruments are closed when a python session is closed.
`connect_message`([idn_param, begin_time])	Print a standard message on initial connection to an instrument.
`device_clear`()	Clear the buffers of the device
`exist`(name[, instrument_class])	Check if an instrument with a given names exists (i.e. is already instantiated).
`find_instrument`(name[, instrument_class])	Find an existing instrument by name.
`get`(param_name)	Shortcut for getting a parameter from its name.
`get_component`(full_name)	Recursively get a component of the instrument by full_name.
`get_idn`()	Parse a standard VISA `*IDN?` response into an ID dict.
`instances`()	Get all currently defined instances of this instrument class.
`invalidate_cache`()	Invalidate the cache of all parameters on the instrument.
`is_valid`(instr_instance)	Check if a given instance of an instrument is valid: if an instrument has been closed, its instance is not longer a "valid" instrument.
`load_metadata`(metadata)	Load metadata into this classes metadata dictionary.
`print_readable_snapshot`([update, max_chars])	Prints a readable version of the snapshot.
`record_instance`(instance)	Record (a weak ref to) an instance in a class's instance list.
`remove_instance`(instance)	Remove a particular instance from the record.
`set`(param_name, value)	Shortcut for setting a parameter from its name and new value.
`set_address`(address)	Set the address for this instrument.
`set_terminator`(terminator)	Change the read terminator to use.
`snapshot`([update])	Decorate a snapshot dictionary with metadata.
`snapshot_base`([update, params_to_skip_update])	State of the instrument as a JSON-compatible dict (everything that the custom JSON encoder class `NumpyJSONEncoder` supports).
`validate_status`([verbose])	Validate the values of all gettable parameters
`write`(cmd)	Write a command string with NO response to the hardware.
`write_raw`(cmd)	Low-level interface to `visa_handle.write`.

Attributes:

`ancestors`	Ancestors in the form of a list of `InstrumentBase`
`delegate_attr_dicts`	A list of names (strings) of dictionaries which are (or will be) attributes of `self`, whose keys should be treated as attributes of `self`.
`delegate_attr_objects`	A list of names (strings) of objects which are (or will be) attributes of `self`, whose attributes should be passed through to `self`.
`full_name`	Full name of the instrument.
`label`	Nicely formatted label of the instrument.
`name`	Full name of the instrument
`name_parts`	A list of all the parts of the instrument name from `root_instrument()` to the current `InstrumentModule`.
`omit_delegate_attrs`	A list of attribute names (strings) to not delegate to any other dictionary or object.
`parent`	The parent instrument.
`root_instrument`	The topmost parent of this module.
`short_name`	Short name of the instrument.
`visa_handle`	The VISA resource used by this instrument.
`resource_manager`	The VISA resource manager used by this instrument.
`parameters`	All the parameters supported by this instrument.
`functions`	All the functions supported by this instrument.
`submodules`	All the submodules of this instrument such as channel lists or logical groupings of parameters.
`instrument_modules`	All the `InstrumentModule` of this instrument Usually populated via `add_submodule()`.

trigger() → None[source]

__del__() → None: Close the instrument and remove its instance record.

__getitem__(key: str) → Callable[..., Any] | Parameter: Delegate instrument[‘name’] to parameter or function ‘name’.

__getstate__() → None: Prevent pickling instruments, and give a nice error message.

__repr__() → str: Simplified repr giving just the class and name.

add_function(name: str, **kwargs: Any) → None

Bind one Function to this instrument.

Instrument subclasses can call this repeatedly in their __init__ for every real function of the instrument.

This functionality is meant for simple cases, principally things that map to simple commands like *RST (reset) or those with just a few arguments. It requires a fixed argument count, and positional args only.

Note

We do not recommend the usage of Function for any new driver. Function does not add any significant features over a method defined on the class.

Parameters:

name – How the Function will be stored within instrument.Functions and also how you address it using the shortcut methods: instrument.call(func_name, *args) etc.
**kwargs – constructor kwargs for Function

Raises:

KeyError – If this instrument already has a function with this name.

add_parameter(name: str, parameter_class: type[ParameterBase] | None = None, **kwargs: Any) → None

Bind one Parameter to this instrument.

Instrument subclasses can call this repeatedly in their __init__ for every real parameter of the instrument.

In this sense, parameters are the state variables of the instrument, anything the user can set and/or get.

Parameters:

name – How the parameter will be stored within parameters and also how you address it using the shortcut methods: instrument.set(param_name, value) etc.
parameter_class – You can construct the parameter out of any class. Default parameters.Parameter.
**kwargs – Constructor arguments for parameter_class.

Raises:

KeyError – If this instrument already has a parameter with this name and the parameter being replaced is not an abstract parameter.
ValueError – If there is an existing abstract parameter and the unit of the new parameter is inconsistent with the existing one.

add_submodule(name: str, submodule: InstrumentModule | ChannelTuple) → None

Bind one submodule to this instrument.

Instrument subclasses can call this repeatedly in their __init__ method for every submodule of the instrument.

Submodules can effectively be considered as instruments within the main instrument, and should at minimum be snapshottable. For example, they can be used to either store logical groupings of parameters, which may or may not be repeated, or channel lists. They should either be an instance of an InstrumentModule or a ChannelTuple.

Parameters:

name – How the submodule will be stored within instrument.submodules and also how it can be addressed.
submodule – The submodule to be stored.

Raises:

KeyError – If this instrument already contains a submodule with this name.
TypeError – If the submodule that we are trying to add is not an instance of an Metadatable object.

property ancestors: tuple[InstrumentBase, ...]

Ancestors in the form of a list of InstrumentBase

The list starts with the current module then the parent and the parents parent until the root instrument is reached.

ask(cmd: str) → str

Write a command string to the hardware and return a response.

Subclasses that transform cmd should override this method, and in it call super().ask(new_cmd). Subclasses that define a new hardware communication should instead override ask_raw.

Parameters:: cmd – The string to send to the instrument.
Returns:: response
Raises:: Exception – Wraps any underlying exception with extra context, including the command and the instrument.

ask_raw(cmd: str) → str

Low-level interface to visa_handle.ask.

Parameters:: cmd – The command to send to the instrument.
Returns:: The instrument’s response.
Return type:: str

call(func_name: str, *args: Any) → Any

Shortcut for calling a function from its name.

Parameters:

func_name – The name of a function of this instrument.
*args – any arguments to the function.

Returns:

The return value of the function.

close() → None: Disconnect and irreversibly tear down the instrument.

classmethod close_all() → None

Try to close all instruments registered in _all_instruments This is handy for use with atexit to ensure that all instruments are closed when a python session is closed.

Examples

>>> atexit.register(qc.Instrument.close_all())

connect_message(idn_param: str = 'IDN', begin_time: float | None = None) → None

Print a standard message on initial connection to an instrument.

Parameters:

idn_param – Name of parameter that returns ID dict. Default IDN.
begin_time – time.time() when init started. Default is self._t0, set at start of Instrument.__init__.

delegate_attr_dicts: ClassVar[list[str]] = ['parameters', 'functions', 'submodules']: A list of names (strings) of dictionaries which are (or will be) attributes of self, whose keys should be treated as attributes of self.

delegate_attr_objects: ClassVar[list[str]] = []: A list of names (strings) of objects which are (or will be) attributes of self, whose attributes should be passed through to self.

device_clear() → None: Clear the buffers of the device

static exist(name: str, instrument_class: type[Instrument] | None = None) → bool

Check if an instrument with a given names exists (i.e. is already instantiated).

Parameters:

name – Name of the instrument.
instrument_class – The type of instrument you are looking for.

classmethod find_instrument(name: str, instrument_class: type[T] | None = None) → T | Instrument

Find an existing instrument by name.

Parameters:

name – Name of the instrument.
instrument_class – The type of instrument you are looking for.

Returns:

The instrument found.

Raises:

KeyError – If no instrument of that name was found, or if its reference is invalid (dead).
TypeError – If a specific class was requested but a different type was found.

property full_name: str

Full name of the instrument.

For an InstrumentModule this includes all parents separated by _

get(param_name: str) → Any

Shortcut for getting a parameter from its name.

Parameters:: param_name – The name of a parameter of this instrument.
Returns:: The current value of the parameter.

get_component(full_name: str) → MetadatableWithName

Recursively get a component of the instrument by full_name.

Parameters:: full_name – The name of the component to get.
Returns:: The component with the given name.
Raises:: KeyError – If the component does not exist.

get_idn() → dict[str, str | None]

Parse a standard VISA *IDN? response into an ID dict.

Even though this is the VISA standard, it applies to various other types as well, such as IPInstruments, so it is included here in the Instrument base class.

Override this if your instrument does not support *IDN? or returns a nonstandard IDN string. This string is supposed to be a comma-separated list of vendor, model, serial, and firmware, but semicolon and colon are also common separators so we accept them here as well.

Returns:: A dict containing vendor, model, serial, and firmware.

classmethod instances() → list[T]

Get all currently defined instances of this instrument class.

You can use this to get the objects back if you lose track of them, and it’s also used by the test system to find objects to test against.

Returns:: A list of instances.

invalidate_cache() → None

Invalidate the cache of all parameters on the instrument. Calling this method will recursively mark the cache of all parameters on the instrument and any parameter on instrument modules as invalid.

This is useful if you have performed manual operations (e.g. using the frontpanel) which changes the state of the instrument outside QCoDeS.

This in turn means that the next snapshot of the instrument will trigger a (potentially slow) reread of all parameters of the instrument if you pass update=None to snapshot.

static is_valid(instr_instance: Instrument) → bool

Check if a given instance of an instrument is valid: if an instrument has been closed, its instance is not longer a “valid” instrument.

Parameters:: instr_instance – Instance of an Instrument class or its subclass.

property label: str: Nicely formatted label of the instrument.

load_metadata(metadata: Mapping[str, Any]) → None

Load metadata into this classes metadata dictionary.

Parameters:: metadata – Metadata to load.

property name: str

Full name of the instrument

This is equivalent to full_name() for backwards compatibility.

property name_parts: list[str]: A list of all the parts of the instrument name from root_instrument() to the current InstrumentModule.

omit_delegate_attrs: ClassVar[list[str]] = []: A list of attribute names (strings) to not delegate to any other dictionary or object.

property parent: InstrumentBase | None: The parent instrument. By default, this is None. Any SubInstrument should subclass this to return the parent instrument.

print_readable_snapshot(update: bool = False, max_chars: int = 80) → None

Prints a readable version of the snapshot. The readable snapshot includes the name, value and unit of each parameter. A convenience function to quickly get an overview of the status of an instrument.

Parameters:

update – If True, update the state by querying the instrument. If False, just use the latest values in memory. This argument gets passed to the snapshot function.
max_chars – the maximum number of characters per line. The readable snapshot will be cropped if this value is exceeded. Defaults to 80 to be consistent with default terminal width.

classmethod record_instance(instance: Instrument) → None

Record (a weak ref to) an instance in a class’s instance list.

Also records the instance in list of all instruments, and verifies that there are no other instruments with the same name.

This method is called after initialization of the instrument is completed.

Parameters:: instance – Instance to record.
Raises:: KeyError – If another instance with the same name is already present.

classmethod remove_instance(instance: Instrument) → None

Remove a particular instance from the record.

Parameters:: instance – The instance to remove

property root_instrument: InstrumentBase

The topmost parent of this module.

For the root_instrument this is self.

set(param_name: str, value: Any) → None

Shortcut for setting a parameter from its name and new value.

Parameters:

param_name – The name of a parameter of this instrument.
value – The new value to set.

set_address(address: str) → None

Set the address for this instrument.

Parameters:: address – The visa resource name to use to connect. The address should be the actual address and just that. If you wish to change the backend for VISA, use the self.visalib attribute (and then call this function).

set_terminator(terminator: str | None) → None

Change the read terminator to use.

Parameters:: terminator – Character(s) to look for at the end of a read and to end each write command with. eg. \r\n. If None the terminator will not be set.

property short_name: str

Short name of the instrument.

For an InstrumentModule this does not include any parent names.

snapshot(update: bool | None = False) → dict[str, Any]

Decorate a snapshot dictionary with metadata. DO NOT override this method if you want metadata in the snapshot instead, override snapshot_base().

Parameters:: update – Passed to snapshot_base.
Returns:: Base snapshot.

snapshot_base(update: bool | None = True, params_to_skip_update: Sequence[str] | None = None) → dict[Any, Any]

State of the instrument as a JSON-compatible dict (everything that the custom JSON encoder class NumpyJSONEncoder supports).

Parameters:

update – If True, update the state by querying the instrument. If None only update if the state is known to be invalid. If False, just use the latest values in memory and never update.
params_to_skip_update – List of parameter names that will be skipped in update even if update is True. This is useful if you have parameters that are slow to update but can be updated in a different way (as in the qdac). If you want to skip the update of certain parameters in all snapshots, use the snapshot_get attribute of those parameters instead.

Returns:

base snapshot

Return type:

dict

validate_status(verbose: bool = False) → None

Validate the values of all gettable parameters

The validation is done for all parameters that have both a get and set method.

Parameters:: verbose – If True, then information about the parameters that are being check is printed.

write(cmd: str) → None

Write a command string with NO response to the hardware.

Subclasses that transform cmd should override this method, and in it call super().write(new_cmd). Subclasses that define a new hardware communication should instead override write_raw.

Parameters:: cmd – The string to send to the instrument.
Raises:: Exception – Wraps any underlying exception with extra context, including the command and the instrument.

write_raw(cmd: str) → None

Low-level interface to visa_handle.write.

Parameters:: cmd – The command to send to the instrument.

visabackend: str = visabackend

visa_handle: pyvisa.resources.MessageBasedResource = visa_handle: The VISA resource used by this instrument.

visalib: str | None = visalib

parameters: dict[str, ParameterBase] = {}: All the parameters supported by this instrument. Usually populated via add_parameter().

functions: dict[str, Function] = {}: All the functions supported by this instrument. Usually populated via add_function().

submodules: dict[str, InstrumentModule | ChannelTuple] = {}: All the submodules of this instrument such as channel lists or logical groupings of parameters. Usually populated via add_submodule().

instrument_modules: dict[str, InstrumentModule] = {}: All the InstrumentModule of this instrument Usually populated via add_submodule().

log: InstrumentLoggerAdapter = get_instrument_logger(self, __name__)

metadata: dict[str, Any] = {}

resource_manager = resource_manager: The VISA resource manager used by this instrument.

class qcodes.instrument_drivers.Keithley.Keithley2400(name: str, address: str, **kwargs: Any)[source]

Bases: VisaInstrument

QCoDeS driver for the Keithley 2400 voltage source.

Methods:

`reset`()	Reset the instrument.
`__del__`()	Close the instrument and remove its instance record.
`__getitem__`(key)	Delegate instrument['name'] to parameter or function 'name'.
`__getstate__`()	Prevent pickling instruments, and give a nice error message.
`__repr__`()	Simplified repr giving just the class and name.
`add_function`(name, **kwargs)	Bind one `Function` to this instrument.
`add_parameter`(name[, parameter_class])	Bind one Parameter to this instrument.
`add_submodule`(name, submodule)	Bind one submodule to this instrument.
`ask`(cmd)	Write a command string to the hardware and return a response.
`ask_raw`(cmd)	Low-level interface to `visa_handle.ask`.
`call`(func_name, *args)	Shortcut for calling a function from its name.
`close`()	Disconnect and irreversibly tear down the instrument.
`close_all`()	Try to close all instruments registered in `_all_instruments` This is handy for use with atexit to ensure that all instruments are closed when a python session is closed.
`connect_message`([idn_param, begin_time])	Print a standard message on initial connection to an instrument.
`device_clear`()	Clear the buffers of the device
`exist`(name[, instrument_class])	Check if an instrument with a given names exists (i.e. is already instantiated).
`find_instrument`(name[, instrument_class])	Find an existing instrument by name.
`get`(param_name)	Shortcut for getting a parameter from its name.
`get_component`(full_name)	Recursively get a component of the instrument by full_name.
`get_idn`()	Parse a standard VISA `*IDN?` response into an ID dict.
`instances`()	Get all currently defined instances of this instrument class.
`invalidate_cache`()	Invalidate the cache of all parameters on the instrument.
`is_valid`(instr_instance)	Check if a given instance of an instrument is valid: if an instrument has been closed, its instance is not longer a "valid" instrument.
`load_metadata`(metadata)	Load metadata into this classes metadata dictionary.
`print_readable_snapshot`([update, max_chars])	Prints a readable version of the snapshot.
`record_instance`(instance)	Record (a weak ref to) an instance in a class's instance list.
`remove_instance`(instance)	Remove a particular instance from the record.
`set`(param_name, value)	Shortcut for setting a parameter from its name and new value.
`set_address`(address)	Set the address for this instrument.
`set_terminator`(terminator)	Change the read terminator to use.
`snapshot`([update])	Decorate a snapshot dictionary with metadata.
`snapshot_base`([update, params_to_skip_update])	State of the instrument as a JSON-compatible dict (everything that the custom JSON encoder class `NumpyJSONEncoder` supports).
`validate_status`([verbose])	Validate the values of all gettable parameters
`write`(cmd)	Write a command string with NO response to the hardware.
`write_raw`(cmd)	Low-level interface to `visa_handle.write`.

Attributes:

`ancestors`	Ancestors in the form of a list of `InstrumentBase`
`delegate_attr_dicts`	A list of names (strings) of dictionaries which are (or will be) attributes of `self`, whose keys should be treated as attributes of `self`.
`delegate_attr_objects`	A list of names (strings) of objects which are (or will be) attributes of `self`, whose attributes should be passed through to `self`.
`full_name`	Full name of the instrument.
`label`	Nicely formatted label of the instrument.
`name`	Full name of the instrument
`name_parts`	A list of all the parts of the instrument name from `root_instrument()` to the current `InstrumentModule`.
`omit_delegate_attrs`	A list of attribute names (strings) to not delegate to any other dictionary or object.
`parent`	The parent instrument.
`root_instrument`	The topmost parent of this module.
`short_name`	Short name of the instrument.
`visa_handle`	The VISA resource used by this instrument.
`resource_manager`	The VISA resource manager used by this instrument.
`parameters`	All the parameters supported by this instrument.
`functions`	All the functions supported by this instrument.
`submodules`	All the submodules of this instrument such as channel lists or logical groupings of parameters.
`instrument_modules`	All the `InstrumentModule` of this instrument Usually populated via `add_submodule()`.

reset() → None[source]: Reset the instrument. When the instrument is reset, it performs the following actions.

Returns the SourceMeter to the GPIB default conditions.

Cancels all pending commands.

Cancels all previously send *OPC and *OPC?

__del__() → None: Close the instrument and remove its instance record.

__getitem__(key: str) → Callable[..., Any] | Parameter: Delegate instrument[‘name’] to parameter or function ‘name’.

__getstate__() → None: Prevent pickling instruments, and give a nice error message.

__repr__() → str: Simplified repr giving just the class and name.

add_function(name: str, **kwargs: Any) → None

Bind one Function to this instrument.

Instrument subclasses can call this repeatedly in their __init__ for every real function of the instrument.

This functionality is meant for simple cases, principally things that map to simple commands like *RST (reset) or those with just a few arguments. It requires a fixed argument count, and positional args only.

Note

We do not recommend the usage of Function for any new driver. Function does not add any significant features over a method defined on the class.

Parameters:

name – How the Function will be stored within instrument.Functions and also how you address it using the shortcut methods: instrument.call(func_name, *args) etc.
**kwargs – constructor kwargs for Function

Raises:

KeyError – If this instrument already has a function with this name.

add_parameter(name: str, parameter_class: type[ParameterBase] | None = None, **kwargs: Any) → None

Bind one Parameter to this instrument.

Instrument subclasses can call this repeatedly in their __init__ for every real parameter of the instrument.

In this sense, parameters are the state variables of the instrument, anything the user can set and/or get.

Parameters:

name – How the parameter will be stored within parameters and also how you address it using the shortcut methods: instrument.set(param_name, value) etc.
parameter_class – You can construct the parameter out of any class. Default parameters.Parameter.
**kwargs – Constructor arguments for parameter_class.

Raises:

KeyError – If this instrument already has a parameter with this name and the parameter being replaced is not an abstract parameter.
ValueError – If there is an existing abstract parameter and the unit of the new parameter is inconsistent with the existing one.

add_submodule(name: str, submodule: InstrumentModule | ChannelTuple) → None

Bind one submodule to this instrument.

Instrument subclasses can call this repeatedly in their __init__ method for every submodule of the instrument.

Submodules can effectively be considered as instruments within the main instrument, and should at minimum be snapshottable. For example, they can be used to either store logical groupings of parameters, which may or may not be repeated, or channel lists. They should either be an instance of an InstrumentModule or a ChannelTuple.

Parameters:

name – How the submodule will be stored within instrument.submodules and also how it can be addressed.
submodule – The submodule to be stored.

Raises:

KeyError – If this instrument already contains a submodule with this name.
TypeError – If the submodule that we are trying to add is not an instance of an Metadatable object.

property ancestors: tuple[InstrumentBase, ...]

Ancestors in the form of a list of InstrumentBase

The list starts with the current module then the parent and the parents parent until the root instrument is reached.

ask(cmd: str) → str

Write a command string to the hardware and return a response.

Subclasses that transform cmd should override this method, and in it call super().ask(new_cmd). Subclasses that define a new hardware communication should instead override ask_raw.

Parameters:: cmd – The string to send to the instrument.
Returns:: response
Raises:: Exception – Wraps any underlying exception with extra context, including the command and the instrument.

ask_raw(cmd: str) → str

Low-level interface to visa_handle.ask.

Parameters:: cmd – The command to send to the instrument.
Returns:: The instrument’s response.
Return type:: str

call(func_name: str, *args: Any) → Any

Shortcut for calling a function from its name.

Parameters:

func_name – The name of a function of this instrument.
*args – any arguments to the function.

Returns:

The return value of the function.

close() → None: Disconnect and irreversibly tear down the instrument.

classmethod close_all() → None

Try to close all instruments registered in _all_instruments This is handy for use with atexit to ensure that all instruments are closed when a python session is closed.

Examples

>>> atexit.register(qc.Instrument.close_all())

connect_message(idn_param: str = 'IDN', begin_time: float | None = None) → None

Print a standard message on initial connection to an instrument.

Parameters:

idn_param – Name of parameter that returns ID dict. Default IDN.
begin_time – time.time() when init started. Default is self._t0, set at start of Instrument.__init__.

delegate_attr_dicts: ClassVar[list[str]] = ['parameters', 'functions', 'submodules']: A list of names (strings) of dictionaries which are (or will be) attributes of self, whose keys should be treated as attributes of self.

delegate_attr_objects: ClassVar[list[str]] = []: A list of names (strings) of objects which are (or will be) attributes of self, whose attributes should be passed through to self.

device_clear() → None: Clear the buffers of the device

static exist(name: str, instrument_class: type[Instrument] | None = None) → bool

Check if an instrument with a given names exists (i.e. is already instantiated).

Parameters:

name – Name of the instrument.
instrument_class – The type of instrument you are looking for.

classmethod find_instrument(name: str, instrument_class: type[T] | None = None) → T | Instrument

Find an existing instrument by name.

Parameters:

name – Name of the instrument.
instrument_class – The type of instrument you are looking for.

Returns:

The instrument found.

Raises:

KeyError – If no instrument of that name was found, or if its reference is invalid (dead).
TypeError – If a specific class was requested but a different type was found.

property full_name: str

Full name of the instrument.

For an InstrumentModule this includes all parents separated by _

get(param_name: str) → Any

Shortcut for getting a parameter from its name.

Parameters:: param_name – The name of a parameter of this instrument.
Returns:: The current value of the parameter.

get_component(full_name: str) → MetadatableWithName

Recursively get a component of the instrument by full_name.

Parameters:: full_name – The name of the component to get.
Returns:: The component with the given name.
Raises:: KeyError – If the component does not exist.

get_idn() → dict[str, str | None]

Parse a standard VISA *IDN? response into an ID dict.

Even though this is the VISA standard, it applies to various other types as well, such as IPInstruments, so it is included here in the Instrument base class.

Override this if your instrument does not support *IDN? or returns a nonstandard IDN string. This string is supposed to be a comma-separated list of vendor, model, serial, and firmware, but semicolon and colon are also common separators so we accept them here as well.

Returns:: A dict containing vendor, model, serial, and firmware.

classmethod instances() → list[T]

Get all currently defined instances of this instrument class.

You can use this to get the objects back if you lose track of them, and it’s also used by the test system to find objects to test against.

Returns:: A list of instances.

invalidate_cache() → None

Invalidate the cache of all parameters on the instrument. Calling this method will recursively mark the cache of all parameters on the instrument and any parameter on instrument modules as invalid.

This is useful if you have performed manual operations (e.g. using the frontpanel) which changes the state of the instrument outside QCoDeS.

This in turn means that the next snapshot of the instrument will trigger a (potentially slow) reread of all parameters of the instrument if you pass update=None to snapshot.

static is_valid(instr_instance: Instrument) → bool

Check if a given instance of an instrument is valid: if an instrument has been closed, its instance is not longer a “valid” instrument.

Parameters:: instr_instance – Instance of an Instrument class or its subclass.

property label: str: Nicely formatted label of the instrument.

load_metadata(metadata: Mapping[str, Any]) → None

Load metadata into this classes metadata dictionary.

Parameters:: metadata – Metadata to load.

property name: str

Full name of the instrument

This is equivalent to full_name() for backwards compatibility.

property name_parts: list[str]: A list of all the parts of the instrument name from root_instrument() to the current InstrumentModule.

omit_delegate_attrs: ClassVar[list[str]] = []: A list of attribute names (strings) to not delegate to any other dictionary or object.

property parent: InstrumentBase | None: The parent instrument. By default, this is None. Any SubInstrument should subclass this to return the parent instrument.

print_readable_snapshot(update: bool = False, max_chars: int = 80) → None

Prints a readable version of the snapshot. The readable snapshot includes the name, value and unit of each parameter. A convenience function to quickly get an overview of the status of an instrument.

Parameters:

update – If True, update the state by querying the instrument. If False, just use the latest values in memory. This argument gets passed to the snapshot function.
max_chars – the maximum number of characters per line. The readable snapshot will be cropped if this value is exceeded. Defaults to 80 to be consistent with default terminal width.

classmethod record_instance(instance: Instrument) → None

Record (a weak ref to) an instance in a class’s instance list.

Also records the instance in list of all instruments, and verifies that there are no other instruments with the same name.

This method is called after initialization of the instrument is completed.

Parameters:: instance – Instance to record.
Raises:: KeyError – If another instance with the same name is already present.

classmethod remove_instance(instance: Instrument) → None

Remove a particular instance from the record.

Parameters:: instance – The instance to remove

property root_instrument: InstrumentBase

The topmost parent of this module.

For the root_instrument this is self.

set(param_name: str, value: Any) → None

Shortcut for setting a parameter from its name and new value.

Parameters:

param_name – The name of a parameter of this instrument.
value – The new value to set.

set_address(address: str) → None

Set the address for this instrument.

Parameters:: address – The visa resource name to use to connect. The address should be the actual address and just that. If you wish to change the backend for VISA, use the self.visalib attribute (and then call this function).

set_terminator(terminator: str | None) → None

Change the read terminator to use.

Parameters:: terminator – Character(s) to look for at the end of a read and to end each write command with. eg. \r\n. If None the terminator will not be set.

property short_name: str

Short name of the instrument.

For an InstrumentModule this does not include any parent names.

snapshot(update: bool | None = False) → dict[str, Any]

Decorate a snapshot dictionary with metadata. DO NOT override this method if you want metadata in the snapshot instead, override snapshot_base().

Parameters:: update – Passed to snapshot_base.
Returns:: Base snapshot.

snapshot_base(update: bool | None = True, params_to_skip_update: Sequence[str] | None = None) → dict[Any, Any]

State of the instrument as a JSON-compatible dict (everything that the custom JSON encoder class NumpyJSONEncoder supports).

Parameters:

update – If True, update the state by querying the instrument. If None only update if the state is known to be invalid. If False, just use the latest values in memory and never update.
params_to_skip_update – List of parameter names that will be skipped in update even if update is True. This is useful if you have parameters that are slow to update but can be updated in a different way (as in the qdac). If you want to skip the update of certain parameters in all snapshots, use the snapshot_get attribute of those parameters instead.

Returns:

base snapshot

Return type:

dict

validate_status(verbose: bool = False) → None

Validate the values of all gettable parameters

The validation is done for all parameters that have both a get and set method.

Parameters:: verbose – If True, then information about the parameters that are being check is printed.

write(cmd: str) → None

Write a command string with NO response to the hardware.

Subclasses that transform cmd should override this method, and in it call super().write(new_cmd). Subclasses that define a new hardware communication should instead override write_raw.

Parameters:: cmd – The string to send to the instrument.
Raises:: Exception – Wraps any underlying exception with extra context, including the command and the instrument.

write_raw(cmd: str) → None

Low-level interface to visa_handle.write.

Parameters:: cmd – The command to send to the instrument.

visabackend: str = visabackend

visa_handle: pyvisa.resources.MessageBasedResource = visa_handle: The VISA resource used by this instrument.

visalib: str | None = visalib

parameters: dict[str, ParameterBase] = {}: All the parameters supported by this instrument. Usually populated via add_parameter().

functions: dict[str, Function] = {}: All the functions supported by this instrument. Usually populated via add_function().

submodules: dict[str, InstrumentModule | ChannelTuple] = {}: All the submodules of this instrument such as channel lists or logical groupings of parameters. Usually populated via add_submodule().

instrument_modules: dict[str, InstrumentModule] = {}: All the InstrumentModule of this instrument Usually populated via add_submodule().

log: InstrumentLoggerAdapter = get_instrument_logger(self, __name__)

metadata: dict[str, Any] = {}

resource_manager = resource_manager: The VISA resource manager used by this instrument.

class qcodes.instrument_drivers.Keithley.Keithley2450(name: str, address: str, **kwargs: Any)[source]

Bases: VisaInstrument

The QCoDeS driver for the Keithley 2450 SMU

Attributes:

`source`	We have different source modules depending on the source function, which can be 'current' or 'voltage'
`sense`	We have different sense modules depending on the sense function, which can be 'current', 'voltage' or 'resistance'
`ancestors`	Ancestors in the form of a list of `InstrumentBase`
`delegate_attr_dicts`	A list of names (strings) of dictionaries which are (or will be) attributes of `self`, whose keys should be treated as attributes of `self`.
`delegate_attr_objects`	A list of names (strings) of objects which are (or will be) attributes of `self`, whose attributes should be passed through to `self`.
`full_name`	Full name of the instrument.
`label`	Nicely formatted label of the instrument.
`name`	Full name of the instrument
`name_parts`	A list of all the parts of the instrument name from `root_instrument()` to the current `InstrumentModule`.
`omit_delegate_attrs`	A list of attribute names (strings) to not delegate to any other dictionary or object.
`parent`	The parent instrument.
`root_instrument`	The topmost parent of this module.
`short_name`	Short name of the instrument.
`visa_handle`	The VISA resource used by this instrument.
`resource_manager`	The VISA resource manager used by this instrument.
`parameters`	All the parameters supported by this instrument.
`functions`	All the functions supported by this instrument.
`submodules`	All the submodules of this instrument such as channel lists or logical groupings of parameters.
`instrument_modules`	All the `InstrumentModule` of this instrument Usually populated via `add_submodule()`.

Methods:

`buffer`(name[, size, style])
`npts`()	Get the number of points in the sweep axis
`set_correct_language`()	The correct communication protocol is SCPI, make sure this is set
`abort`()	This command stops all trigger model commands on the instrument.
`initiate`()	This command starts the trigger model.
`wait`()	This command postpones the execution of subsequent commands until all previous overlapped commands are finished.
`clear_event_register`()	This function clears event registers.
`clear_event_log`()	This command clears the event log.
`reset`()	Returns instrument to default settings, cancels all pending commands.
`__del__`()	Close the instrument and remove its instance record.
`__getitem__`(key)	Delegate instrument['name'] to parameter or function 'name'.
`__getstate__`()	Prevent pickling instruments, and give a nice error message.
`__repr__`()	Simplified repr giving just the class and name.
`add_function`(name, **kwargs)	Bind one `Function` to this instrument.
`add_parameter`(name[, parameter_class])	Bind one Parameter to this instrument.
`add_submodule`(name, submodule)	Bind one submodule to this instrument.
`ask`(cmd)	Write a command string to the hardware and return a response.
`ask_raw`(cmd)	Low-level interface to `visa_handle.ask`.
`call`(func_name, *args)	Shortcut for calling a function from its name.
`close`()	Disconnect and irreversibly tear down the instrument.
`close_all`()	Try to close all instruments registered in `_all_instruments` This is handy for use with atexit to ensure that all instruments are closed when a python session is closed.
`connect_message`([idn_param, begin_time])	Print a standard message on initial connection to an instrument.
`device_clear`()	Clear the buffers of the device
`exist`(name[, instrument_class])	Check if an instrument with a given names exists (i.e. is already instantiated).
`find_instrument`(name[, instrument_class])	Find an existing instrument by name.
`get`(param_name)	Shortcut for getting a parameter from its name.
`get_component`(full_name)	Recursively get a component of the instrument by full_name.
`get_idn`()	Parse a standard VISA `*IDN?` response into an ID dict.
`instances`()	Get all currently defined instances of this instrument class.
`invalidate_cache`()	Invalidate the cache of all parameters on the instrument.
`is_valid`(instr_instance)	Check if a given instance of an instrument is valid: if an instrument has been closed, its instance is not longer a "valid" instrument.
`load_metadata`(metadata)	Load metadata into this classes metadata dictionary.
`print_readable_snapshot`([update, max_chars])	Prints a readable version of the snapshot.
`record_instance`(instance)	Record (a weak ref to) an instance in a class's instance list.
`remove_instance`(instance)	Remove a particular instance from the record.
`set`(param_name, value)	Shortcut for setting a parameter from its name and new value.
`set_address`(address)	Set the address for this instrument.
`set_terminator`(terminator)	Change the read terminator to use.
`snapshot`([update])	Decorate a snapshot dictionary with metadata.
`snapshot_base`([update, params_to_skip_update])	State of the instrument as a JSON-compatible dict (everything that the custom JSON encoder class `NumpyJSONEncoder` supports).
`validate_status`([verbose])	Validate the values of all gettable parameters
`write`(cmd)	Write a command string with NO response to the hardware.
`write_raw`(cmd)	Low-level interface to `visa_handle.write`.

property source: Keithley2450Source

We have different source modules depending on the source function, which can be ‘current’ or ‘voltage’

Return the correct source module based on the source function

property sense: Keithley2450Sense

We have different sense modules depending on the sense function, which can be ‘current’, ‘voltage’ or ‘resistance’

Return the correct source module based on the sense function

buffer(name: str, size: int | None = None, style: str = '') → Keithley2450Buffer[source]

npts() → int[source]: Get the number of points in the sweep axis

set_correct_language() → None[source]: The correct communication protocol is SCPI, make sure this is set

abort() → None[source]: This command stops all trigger model commands on the instrument.

initiate() → None[source]: This command starts the trigger model.

wait() → None[source]: This command postpones the execution of subsequent commands until all previous overlapped commands are finished.

clear_event_register() → None[source]: This function clears event registers.

clear_event_log() → None[source]: This command clears the event log.

reset() → None[source]: Returns instrument to default settings, cancels all pending commands.

__del__() → None: Close the instrument and remove its instance record.

__getitem__(key: str) → Callable[..., Any] | Parameter: Delegate instrument[‘name’] to parameter or function ‘name’.

__getstate__() → None: Prevent pickling instruments, and give a nice error message.

__repr__() → str: Simplified repr giving just the class and name.

add_function(name: str, **kwargs: Any) → None

Bind one Function to this instrument.

Instrument subclasses can call this repeatedly in their __init__ for every real function of the instrument.

This functionality is meant for simple cases, principally things that map to simple commands like *RST (reset) or those with just a few arguments. It requires a fixed argument count, and positional args only.

Note

We do not recommend the usage of Function for any new driver. Function does not add any significant features over a method defined on the class.

Parameters:

name – How the Function will be stored within instrument.Functions and also how you address it using the shortcut methods: instrument.call(func_name, *args) etc.
**kwargs – constructor kwargs for Function

Raises:

KeyError – If this instrument already has a function with this name.

add_parameter(name: str, parameter_class: type[ParameterBase] | None = None, **kwargs: Any) → None

Bind one Parameter to this instrument.

Instrument subclasses can call this repeatedly in their __init__ for every real parameter of the instrument.

In this sense, parameters are the state variables of the instrument, anything the user can set and/or get.

Parameters:

name – How the parameter will be stored within parameters and also how you address it using the shortcut methods: instrument.set(param_name, value) etc.
parameter_class – You can construct the parameter out of any class. Default parameters.Parameter.
**kwargs – Constructor arguments for parameter_class.

Raises:

KeyError – If this instrument already has a parameter with this name and the parameter being replaced is not an abstract parameter.
ValueError – If there is an existing abstract parameter and the unit of the new parameter is inconsistent with the existing one.

add_submodule(name: str, submodule: InstrumentModule | ChannelTuple) → None

Bind one submodule to this instrument.

Instrument subclasses can call this repeatedly in their __init__ method for every submodule of the instrument.

Submodules can effectively be considered as instruments within the main instrument, and should at minimum be snapshottable. For example, they can be used to either store logical groupings of parameters, which may or may not be repeated, or channel lists. They should either be an instance of an InstrumentModule or a ChannelTuple.

Parameters:

name – How the submodule will be stored within instrument.submodules and also how it can be addressed.
submodule – The submodule to be stored.

Raises:

KeyError – If this instrument already contains a submodule with this name.
TypeError – If the submodule that we are trying to add is not an instance of an Metadatable object.

property ancestors: tuple[InstrumentBase, ...]

Ancestors in the form of a list of InstrumentBase

The list starts with the current module then the parent and the parents parent until the root instrument is reached.

ask(cmd: str) → str

Write a command string to the hardware and return a response.

Subclasses that transform cmd should override this method, and in it call super().ask(new_cmd). Subclasses that define a new hardware communication should instead override ask_raw.

Parameters:: cmd – The string to send to the instrument.
Returns:: response
Raises:: Exception – Wraps any underlying exception with extra context, including the command and the instrument.

ask_raw(cmd: str) → str

Low-level interface to visa_handle.ask.

Parameters:: cmd – The command to send to the instrument.
Returns:: The instrument’s response.
Return type:: str

call(func_name: str, *args: Any) → Any

Shortcut for calling a function from its name.

Parameters:

func_name – The name of a function of this instrument.
*args – any arguments to the function.

Returns:

The return value of the function.

close() → None: Disconnect and irreversibly tear down the instrument.

classmethod close_all() → None

Try to close all instruments registered in _all_instruments This is handy for use with atexit to ensure that all instruments are closed when a python session is closed.

Examples

>>> atexit.register(qc.Instrument.close_all())

connect_message(idn_param: str = 'IDN', begin_time: float | None = None) → None

Print a standard message on initial connection to an instrument.

Parameters:

idn_param – Name of parameter that returns ID dict. Default IDN.
begin_time – time.time() when init started. Default is self._t0, set at start of Instrument.__init__.

delegate_attr_dicts: ClassVar[list[str]] = ['parameters', 'functions', 'submodules']: A list of names (strings) of dictionaries which are (or will be) attributes of self, whose keys should be treated as attributes of self.

delegate_attr_objects: ClassVar[list[str]] = []: A list of names (strings) of objects which are (or will be) attributes of self, whose attributes should be passed through to self.

device_clear() → None: Clear the buffers of the device

static exist(name: str, instrument_class: type[Instrument] | None = None) → bool

Check if an instrument with a given names exists (i.e. is already instantiated).

Parameters:

name – Name of the instrument.
instrument_class – The type of instrument you are looking for.

classmethod find_instrument(name: str, instrument_class: type[T] | None = None) → T | Instrument

Find an existing instrument by name.

Parameters:

name – Name of the instrument.
instrument_class – The type of instrument you are looking for.

Returns:

The instrument found.

Raises:

KeyError – If no instrument of that name was found, or if its reference is invalid (dead).
TypeError – If a specific class was requested but a different type was found.

property full_name: str

Full name of the instrument.

For an InstrumentModule this includes all parents separated by _

get(param_name: str) → Any

Shortcut for getting a parameter from its name.

Parameters:: param_name – The name of a parameter of this instrument.
Returns:: The current value of the parameter.

get_component(full_name: str) → MetadatableWithName

Recursively get a component of the instrument by full_name.

Parameters:: full_name – The name of the component to get.
Returns:: The component with the given name.
Raises:: KeyError – If the component does not exist.

get_idn() → dict[str, str | None]

Parse a standard VISA *IDN? response into an ID dict.

Even though this is the VISA standard, it applies to various other types as well, such as IPInstruments, so it is included here in the Instrument base class.

Override this if your instrument does not support *IDN? or returns a nonstandard IDN string. This string is supposed to be a comma-separated list of vendor, model, serial, and firmware, but semicolon and colon are also common separators so we accept them here as well.

Returns:: A dict containing vendor, model, serial, and firmware.

classmethod instances() → list[T]

Get all currently defined instances of this instrument class.

You can use this to get the objects back if you lose track of them, and it’s also used by the test system to find objects to test against.

Returns:: A list of instances.

invalidate_cache() → None

Invalidate the cache of all parameters on the instrument. Calling this method will recursively mark the cache of all parameters on the instrument and any parameter on instrument modules as invalid.

This is useful if you have performed manual operations (e.g. using the frontpanel) which changes the state of the instrument outside QCoDeS.

This in turn means that the next snapshot of the instrument will trigger a (potentially slow) reread of all parameters of the instrument if you pass update=None to snapshot.

static is_valid(instr_instance: Instrument) → bool

Check if a given instance of an instrument is valid: if an instrument has been closed, its instance is not longer a “valid” instrument.

Parameters:: instr_instance – Instance of an Instrument class or its subclass.

property label: str: Nicely formatted label of the instrument.

load_metadata(metadata: Mapping[str, Any]) → None

Load metadata into this classes metadata dictionary.

Parameters:: metadata – Metadata to load.

property name: str

Full name of the instrument

This is equivalent to full_name() for backwards compatibility.

property name_parts: list[str]: A list of all the parts of the instrument name from root_instrument() to the current InstrumentModule.

omit_delegate_attrs: ClassVar[list[str]] = []: A list of attribute names (strings) to not delegate to any other dictionary or object.

property parent: InstrumentBase | None: The parent instrument. By default, this is None. Any SubInstrument should subclass this to return the parent instrument.

print_readable_snapshot(update: bool = False, max_chars: int = 80) → None

Prints a readable version of the snapshot. The readable snapshot includes the name, value and unit of each parameter. A convenience function to quickly get an overview of the status of an instrument.

Parameters:

update – If True, update the state by querying the instrument. If False, just use the latest values in memory. This argument gets passed to the snapshot function.
max_chars – the maximum number of characters per line. The readable snapshot will be cropped if this value is exceeded. Defaults to 80 to be consistent with default terminal width.

classmethod record_instance(instance: Instrument) → None

Record (a weak ref to) an instance in a class’s instance list.

Also records the instance in list of all instruments, and verifies that there are no other instruments with the same name.

This method is called after initialization of the instrument is completed.

Parameters:: instance – Instance to record.
Raises:: KeyError – If another instance with the same name is already present.

classmethod remove_instance(instance: Instrument) → None

Remove a particular instance from the record.

Parameters:: instance – The instance to remove

property root_instrument: InstrumentBase

The topmost parent of this module.

For the root_instrument this is self.

set(param_name: str, value: Any) → None

Shortcut for setting a parameter from its name and new value.

Parameters:

param_name – The name of a parameter of this instrument.
value – The new value to set.

set_address(address: str) → None

Set the address for this instrument.

Parameters:: address – The visa resource name to use to connect. The address should be the actual address and just that. If you wish to change the backend for VISA, use the self.visalib attribute (and then call this function).

set_terminator(terminator: str | None) → None

Change the read terminator to use.

Parameters:: terminator – Character(s) to look for at the end of a read and to end each write command with. eg. \r\n. If None the terminator will not be set.

property short_name: str

Short name of the instrument.

For an InstrumentModule this does not include any parent names.

snapshot(update: bool | None = False) → dict[str, Any]

Decorate a snapshot dictionary with metadata. DO NOT override this method if you want metadata in the snapshot instead, override snapshot_base().

Parameters:: update – Passed to snapshot_base.
Returns:: Base snapshot.

snapshot_base(update: bool | None = True, params_to_skip_update: Sequence[str] | None = None) → dict[Any, Any]

State of the instrument as a JSON-compatible dict (everything that the custom JSON encoder class NumpyJSONEncoder supports).

Parameters:

update – If True, update the state by querying the instrument. If None only update if the state is known to be invalid. If False, just use the latest values in memory and never update.
params_to_skip_update – List of parameter names that will be skipped in update even if update is True. This is useful if you have parameters that are slow to update but can be updated in a different way (as in the qdac). If you want to skip the update of certain parameters in all snapshots, use the snapshot_get attribute of those parameters instead.

Returns:

base snapshot

Return type:

dict

validate_status(verbose: bool = False) → None

Validate the values of all gettable parameters

The validation is done for all parameters that have both a get and set method.

Parameters:: verbose – If True, then information about the parameters that are being check is printed.

write(cmd: str) → None

Write a command string with NO response to the hardware.

Subclasses that transform cmd should override this method, and in it call super().write(new_cmd). Subclasses that define a new hardware communication should instead override write_raw.

Parameters:: cmd – The string to send to the instrument.
Raises:: Exception – Wraps any underlying exception with extra context, including the command and the instrument.

write_raw(cmd: str) → None

Low-level interface to visa_handle.write.

Parameters:: cmd – The command to send to the instrument.

visabackend: str = visabackend

visa_handle: pyvisa.resources.MessageBasedResource = visa_handle: The VISA resource used by this instrument.

visalib: str | None = visalib

parameters: dict[str, ParameterBase] = {}: All the parameters supported by this instrument. Usually populated via add_parameter().

functions: dict[str, Function] = {}: All the functions supported by this instrument. Usually populated via add_function().

submodules: dict[str, InstrumentModule | ChannelTuple] = {}: All the submodules of this instrument such as channel lists or logical groupings of parameters. Usually populated via add_submodule().

instrument_modules: dict[str, InstrumentModule] = {}: All the InstrumentModule of this instrument Usually populated via add_submodule().

log: InstrumentLoggerAdapter = get_instrument_logger(self, __name__)

metadata: dict[str, Any] = {}

resource_manager = resource_manager: The VISA resource manager used by this instrument.

class qcodes.instrument_drivers.Keithley.Keithley2450Buffer(parent: Keithley2450, name: str, size: int | None = None, style: str = '')[source]

Bases: InstrumentChannel

Treat the reading buffer as a submodule, similar to Sense and Source

Attributes:

`default_buffer`
`buffer_elements`
`inverted_buffer_elements`
`available_elements`
`ancestors`	Ancestors in the form of a list of `InstrumentBase`
`delegate_attr_dicts`	A list of names (strings) of dictionaries which are (or will be) attributes of `self`, whose keys should be treated as attributes of `self`.
`delegate_attr_objects`	A list of names (strings) of objects which are (or will be) attributes of `self`, whose attributes should be passed through to `self`.
`full_name`	Full name of the instrument.
`label`	Nicely formatted label of the instrument.
`name`	Full name of the instrument
`name_parts`	A list of all the parts of the instrument name from `root_instrument()` to the current `InstrumentModule`.
`omit_delegate_attrs`	A list of attribute names (strings) to not delegate to any other dictionary or object.
`parent`	The parent instrument.
`root_instrument`	The topmost parent of this module.
`short_name`	Short name of the instrument.
`parameters`	All the parameters supported by this instrument.
`functions`	All the functions supported by this instrument.
`submodules`	All the submodules of this instrument such as channel lists or logical groupings of parameters.
`instrument_modules`	All the `InstrumentModule` of this instrument Usually populated via `add_submodule()`.

Methods:

`from_name_to_scpi`(element_names)
`from_scpi_to_name`(element_scpis)
`get_last_reading`()	This method requests the latest reading from a reading buffer.
`get_data`(start_idx, end_idx[, readings_only])	This command returns specified data elements from reading buffer.
`clear_buffer`()	Clear the data in the buffer
`trigger_start`()	This method makes readings using the active measure function and stores them in a reading buffer.
`delete`()
`__getitem__`(key)	Delegate instrument['name'] to parameter or function 'name'.
`__getstate__`()	Prevent pickling instruments, and give a nice error message.
`__repr__`()	Custom repr to give parent information
`add_function`(name, **kwargs)	Bind one `Function` to this instrument.
`add_parameter`(name[, parameter_class])	Bind one Parameter to this instrument.
`add_submodule`(name, submodule)	Bind one submodule to this instrument.
`ask`(cmd)
`ask_raw`(cmd)
`call`(func_name, *args)	Shortcut for calling a function from its name.
`get`(param_name)	Shortcut for getting a parameter from its name.
`get_component`(full_name)	Recursively get a component of the instrument by full_name.
`invalidate_cache`()	Invalidate the cache of all parameters on the instrument.
`load_metadata`(metadata)	Load metadata into this classes metadata dictionary.
`print_readable_snapshot`([update, max_chars])	Prints a readable version of the snapshot.
`set`(param_name, value)	Shortcut for setting a parameter from its name and new value.
`snapshot`([update])	Decorate a snapshot dictionary with metadata.
`snapshot_base`([update, params_to_skip_update])	State of the instrument as a JSON-compatible dict (everything that the custom JSON encoder class `NumpyJSONEncoder` supports).
`validate_status`([verbose])	Validate the values of all gettable parameters
`write`(cmd)
`write_raw`(cmd)

default_buffer: ClassVar[set[str]] = {'defbuffer1', 'defbuffer2'}

buffer_elements: ClassVar[dict[str, str]] = {'date': 'DATE', 'fractional_seconds': 'FRACtional', 'measurement': 'READing', 'measurement_formatted': 'FORMatted', 'measurement_status': 'STATus', 'measurement_unit': 'UNIT', 'relative_time': 'RELative', 'seconds': 'SEConds', 'source_value': 'SOURce', 'source_value_formatted': 'SOURFORMatted', 'source_value_status': 'SOURSTATus', 'source_value_unit': 'SOURUNIT', 'time': 'TIME', 'timestamp': 'TSTamp'}

inverted_buffer_elements = {'DATE': 'date', 'FORMatted': 'measurement_formatted', 'FRACtional': 'fractional_seconds', 'READing': 'measurement', 'RELative': 'relative_time', 'SEConds': 'seconds', 'SOURFORMatted': 'source_value_formatted', 'SOURSTATus': 'source_value_status', 'SOURUNIT': 'source_value_unit', 'SOURce': 'source_value', 'STATus': 'measurement_status', 'TIME': 'time', 'TSTamp': 'timestamp', 'UNIT': 'measurement_unit'}

from_name_to_scpi(element_names: list[str]) → list[str][source]

from_scpi_to_name(element_scpis: list[str]) → list[str][source]

property available_elements: set[str]

get_last_reading() → str[source]: This method requests the latest reading from a reading buffer.

get_data(start_idx: int, end_idx: int, readings_only: bool = False) → list[Any][source]

This command returns specified data elements from reading buffer.

Parameters:

start_idx – beginning index of the buffer to return
end_idx – ending index of the buffer to return
readings_only – a flag to temporarily disable the elements and output only the numerical readings

Returns:

data elements from the reading buffer

clear_buffer() → None[source]: Clear the data in the buffer

trigger_start() → None[source]: This method makes readings using the active measure function and stores them in a reading buffer.

delete() → None[source]

__getitem__(key: str) → Callable[..., Any] | Parameter: Delegate instrument[‘name’] to parameter or function ‘name’.

__getstate__() → None: Prevent pickling instruments, and give a nice error message.

__repr__() → str: Custom repr to give parent information

add_function(name: str, **kwargs: Any) → None

Bind one Function to this instrument.

Instrument subclasses can call this repeatedly in their __init__ for every real function of the instrument.

This functionality is meant for simple cases, principally things that map to simple commands like *RST (reset) or those with just a few arguments. It requires a fixed argument count, and positional args only.

Note

We do not recommend the usage of Function for any new driver. Function does not add any significant features over a method defined on the class.

Parameters:

name – How the Function will be stored within instrument.Functions and also how you address it using the shortcut methods: instrument.call(func_name, *args) etc.
**kwargs – constructor kwargs for Function

Raises:

KeyError – If this instrument already has a function with this name.

add_parameter(name: str, parameter_class: type[ParameterBase] | None = None, **kwargs: Any) → None

Bind one Parameter to this instrument.

Instrument subclasses can call this repeatedly in their __init__ for every real parameter of the instrument.

In this sense, parameters are the state variables of the instrument, anything the user can set and/or get.

Parameters:

name – How the parameter will be stored within parameters and also how you address it using the shortcut methods: instrument.set(param_name, value) etc.
parameter_class – You can construct the parameter out of any class. Default parameters.Parameter.
**kwargs – Constructor arguments for parameter_class.

Raises:

KeyError – If this instrument already has a parameter with this name and the parameter being replaced is not an abstract parameter.
ValueError – If there is an existing abstract parameter and the unit of the new parameter is inconsistent with the existing one.

add_submodule(name: str, submodule: InstrumentModule | ChannelTuple) → None

Bind one submodule to this instrument.

Instrument subclasses can call this repeatedly in their __init__ method for every submodule of the instrument.

Submodules can effectively be considered as instruments within the main instrument, and should at minimum be snapshottable. For example, they can be used to either store logical groupings of parameters, which may or may not be repeated, or channel lists. They should either be an instance of an InstrumentModule or a ChannelTuple.

Parameters:

name – How the submodule will be stored within instrument.submodules and also how it can be addressed.
submodule – The submodule to be stored.

Raises:

KeyError – If this instrument already contains a submodule with this name.
TypeError – If the submodule that we are trying to add is not an instance of an Metadatable object.

property ancestors: tuple[InstrumentBase, ...]

Ancestors in the form of a list of InstrumentBase

The list starts with the current module then the parent and the parents parent until the root instrument is reached.

ask(cmd: str) → str

ask_raw(cmd: str) → str

call(func_name: str, *args: Any) → Any

Shortcut for calling a function from its name.

Parameters:

func_name – The name of a function of this instrument.
*args – any arguments to the function.

Returns:

The return value of the function.

delegate_attr_dicts: ClassVar[list[str]] = ['parameters', 'functions', 'submodules']: A list of names (strings) of dictionaries which are (or will be) attributes of self, whose keys should be treated as attributes of self.

delegate_attr_objects: ClassVar[list[str]] = []: A list of names (strings) of objects which are (or will be) attributes of self, whose attributes should be passed through to self.

property full_name: str

Full name of the instrument.

For an InstrumentModule this includes all parents separated by _

get(param_name: str) → Any

Shortcut for getting a parameter from its name.

Parameters:: param_name – The name of a parameter of this instrument.
Returns:: The current value of the parameter.

get_component(full_name: str) → MetadatableWithName

Recursively get a component of the instrument by full_name.

Parameters:: full_name – The name of the component to get.
Returns:: The component with the given name.
Raises:: KeyError – If the component does not exist.

invalidate_cache() → None

Invalidate the cache of all parameters on the instrument. Calling this method will recursively mark the cache of all parameters on the instrument and any parameter on instrument modules as invalid.

This is useful if you have performed manual operations (e.g. using the frontpanel) which changes the state of the instrument outside QCoDeS.

This in turn means that the next snapshot of the instrument will trigger a (potentially slow) reread of all parameters of the instrument if you pass update=None to snapshot.

property label: str: Nicely formatted label of the instrument.

load_metadata(metadata: Mapping[str, Any]) → None

Load metadata into this classes metadata dictionary.

Parameters:: metadata – Metadata to load.

property name: str

Full name of the instrument

This is equivalent to full_name() for backwards compatibility.

property name_parts: list[str]: A list of all the parts of the instrument name from root_instrument() to the current InstrumentModule.

omit_delegate_attrs: ClassVar[list[str]] = []: A list of attribute names (strings) to not delegate to any other dictionary or object.

property parent: InstrumentBase: The parent instrument. By default, this is None. Any SubInstrument should subclass this to return the parent instrument.

print_readable_snapshot(update: bool = False, max_chars: int = 80) → None

Prints a readable version of the snapshot. The readable snapshot includes the name, value and unit of each parameter. A convenience function to quickly get an overview of the status of an instrument.

Parameters:

update – If True, update the state by querying the instrument. If False, just use the latest values in memory. This argument gets passed to the snapshot function.
max_chars – the maximum number of characters per line. The readable snapshot will be cropped if this value is exceeded. Defaults to 80 to be consistent with default terminal width.

property root_instrument: InstrumentBase

The topmost parent of this module.

For the root_instrument this is self.

set(param_name: str, value: Any) → None

Shortcut for setting a parameter from its name and new value.

Parameters:

param_name – The name of a parameter of this instrument.
value – The new value to set.

property short_name: str

Short name of the instrument.

For an InstrumentModule this does not include any parent names.

snapshot(update: bool | None = False) → dict[str, Any]

Decorate a snapshot dictionary with metadata. DO NOT override this method if you want metadata in the snapshot instead, override snapshot_base().

Parameters:: update – Passed to snapshot_base.
Returns:: Base snapshot.

snapshot_base(update: bool | None = False, params_to_skip_update: Sequence[str] | None = None) → dict[Any, Any]

State of the instrument as a JSON-compatible dict (everything that the custom JSON encoder class NumpyJSONEncoder supports).

Parameters:

update – If True, update the state by querying the instrument. If None update the state if known to be invalid. If False, just use the latest values in memory and never update state.
params_to_skip_update – List of parameter names that will be skipped in update even if update is True. This is useful if you have parameters that are slow to update but can be updated in a different way (as in the qdac). If you want to skip the update of certain parameters in all snapshots, use the snapshot_get attribute of those parameters instead.

Returns:

base snapshot

Return type:

dict

validate_status(verbose: bool = False) → None

Validate the values of all gettable parameters

The validation is done for all parameters that have both a get and set method.

Parameters:: verbose – If True, then information about the parameters that are being check is printed.

write(cmd: str) → None

write_raw(cmd: str) → None

parameters: dict[str, ParameterBase] = {}: All the parameters supported by this instrument. Usually populated via add_parameter().

functions: dict[str, Function] = {}: All the functions supported by this instrument. Usually populated via add_function().

submodules: dict[str, InstrumentModule | ChannelTuple] = {}: All the submodules of this instrument such as channel lists or logical groupings of parameters. Usually populated via add_submodule().

instrument_modules: dict[str, InstrumentModule] = {}: All the InstrumentModule of this instrument Usually populated via add_submodule().

log: InstrumentLoggerAdapter = get_instrument_logger(self, __name__)

metadata: dict[str, Any] = {}

class qcodes.instrument_drivers.Keithley.Keithley2450Sense(parent: Keithley2450, name: str, proper_function: str)[source]

Bases: InstrumentChannel

The sense module of the Keithley 2450 SMU.

Parameters:

parent
name
proper_function – This can be one of either “current”, “voltage” or “resistance”. All parameters and methods in this submodule should only be accessible to the user if self.parent.sense_function.get() == self._proper_function. We ensure this through the ‘sense’ property on the main driver class which returns the proper submodule for any given function mode

Attributes:

`function_modes`
`ancestors`	Ancestors in the form of a list of `InstrumentBase`
`delegate_attr_dicts`	A list of names (strings) of dictionaries which are (or will be) attributes of `self`, whose keys should be treated as attributes of `self`.
`delegate_attr_objects`	A list of names (strings) of objects which are (or will be) attributes of `self`, whose attributes should be passed through to `self`.
`full_name`	Full name of the instrument.
`label`	Nicely formatted label of the instrument.
`name`	Full name of the instrument
`name_parts`	A list of all the parts of the instrument name from `root_instrument()` to the current `InstrumentModule`.
`omit_delegate_attrs`	A list of attribute names (strings) to not delegate to any other dictionary or object.
`parent`	The parent instrument.
`root_instrument`	The topmost parent of this module.
`short_name`	Short name of the instrument.
`parameters`	All the parameters supported by this instrument.
`functions`	All the functions supported by this instrument.
`submodules`	All the submodules of this instrument such as channel lists or logical groupings of parameters.
`instrument_modules`	All the `InstrumentModule` of this instrument Usually populated via `add_submodule()`.

Methods:

`auto_zero_once`()	This command causes the instrument to refresh the reference and zero measurements once.
`clear_trace`([buffer_name])	Clear the data buffer
`__getitem__`(key)	Delegate instrument['name'] to parameter or function 'name'.
`__getstate__`()	Prevent pickling instruments, and give a nice error message.
`__repr__`()	Custom repr to give parent information
`add_function`(name, **kwargs)	Bind one `Function` to this instrument.
`add_parameter`(name[, parameter_class])	Bind one Parameter to this instrument.
`add_submodule`(name, submodule)	Bind one submodule to this instrument.
`ask`(cmd)
`ask_raw`(cmd)
`call`(func_name, *args)	Shortcut for calling a function from its name.
`get`(param_name)	Shortcut for getting a parameter from its name.
`get_component`(full_name)	Recursively get a component of the instrument by full_name.
`invalidate_cache`()	Invalidate the cache of all parameters on the instrument.
`load_metadata`(metadata)	Load metadata into this classes metadata dictionary.
`print_readable_snapshot`([update, max_chars])	Prints a readable version of the snapshot.
`set`(param_name, value)	Shortcut for setting a parameter from its name and new value.
`snapshot`([update])	Decorate a snapshot dictionary with metadata.
`snapshot_base`([update, params_to_skip_update])	State of the instrument as a JSON-compatible dict (everything that the custom JSON encoder class `NumpyJSONEncoder` supports).
`validate_status`([verbose])	Validate the values of all gettable parameters
`write`(cmd)
`write_raw`(cmd)

function_modes: ClassVar[dict[str, _FunctionMode]] = {'current': {'name': '"CURR:DC"', 'range_vals': <Numbers 1e-08<=v<=1>, 'unit': 'A'}, 'resistance': {'name': '"RES"', 'range_vals': <Numbers 20<=v<=200000000.0>, 'unit': 'Ohm'}, 'voltage': {'name': '"VOLT:DC"', 'range_vals': <Numbers 0.02<=v<=200>, 'unit': 'V'}}

auto_zero_once() → None[source]: This command causes the instrument to refresh the reference and zero measurements once.

clear_trace(buffer_name: str = 'defbuffer1') → None[source]: Clear the data buffer

__getitem__(key: str) → Callable[..., Any] | Parameter: Delegate instrument[‘name’] to parameter or function ‘name’.

__getstate__() → None: Prevent pickling instruments, and give a nice error message.

__repr__() → str: Custom repr to give parent information

add_function(name: str, **kwargs: Any) → None

Bind one Function to this instrument.

Instrument subclasses can call this repeatedly in their __init__ for every real function of the instrument.

This functionality is meant for simple cases, principally things that map to simple commands like *RST (reset) or those with just a few arguments. It requires a fixed argument count, and positional args only.

Note

We do not recommend the usage of Function for any new driver. Function does not add any significant features over a method defined on the class.

Parameters:

name – How the Function will be stored within instrument.Functions and also how you address it using the shortcut methods: instrument.call(func_name, *args) etc.
**kwargs – constructor kwargs for Function

Raises:

KeyError – If this instrument already has a function with this name.

add_parameter(name: str, parameter_class: type[ParameterBase] | None = None, **kwargs: Any) → None

Bind one Parameter to this instrument.

Instrument subclasses can call this repeatedly in their __init__ for every real parameter of the instrument.

In this sense, parameters are the state variables of the instrument, anything the user can set and/or get.

Parameters:

name – How the parameter will be stored within parameters and also how you address it using the shortcut methods: instrument.set(param_name, value) etc.
parameter_class – You can construct the parameter out of any class. Default parameters.Parameter.
**kwargs – Constructor arguments for parameter_class.

Raises:

KeyError – If this instrument already has a parameter with this name and the parameter being replaced is not an abstract parameter.
ValueError – If there is an existing abstract parameter and the unit of the new parameter is inconsistent with the existing one.

add_submodule(name: str, submodule: InstrumentModule | ChannelTuple) → None

Bind one submodule to this instrument.

Instrument subclasses can call this repeatedly in their __init__ method for every submodule of the instrument.

Submodules can effectively be considered as instruments within the main instrument, and should at minimum be snapshottable. For example, they can be used to either store logical groupings of parameters, which may or may not be repeated, or channel lists. They should either be an instance of an InstrumentModule or a ChannelTuple.

Parameters:

name – How the submodule will be stored within instrument.submodules and also how it can be addressed.
submodule – The submodule to be stored.

Raises:

KeyError – If this instrument already contains a submodule with this name.
TypeError – If the submodule that we are trying to add is not an instance of an Metadatable object.

property ancestors: tuple[InstrumentBase, ...]

Ancestors in the form of a list of InstrumentBase

The list starts with the current module then the parent and the parents parent until the root instrument is reached.

ask(cmd: str) → str

ask_raw(cmd: str) → str

call(func_name: str, *args: Any) → Any

Shortcut for calling a function from its name.

Parameters:

func_name – The name of a function of this instrument.
*args – any arguments to the function.

Returns:

The return value of the function.

delegate_attr_dicts: ClassVar[list[str]] = ['parameters', 'functions', 'submodules']: A list of names (strings) of dictionaries which are (or will be) attributes of self, whose keys should be treated as attributes of self.

delegate_attr_objects: ClassVar[list[str]] = []: A list of names (strings) of objects which are (or will be) attributes of self, whose attributes should be passed through to self.

property full_name: str

Full name of the instrument.

For an InstrumentModule this includes all parents separated by _

get(param_name: str) → Any

Shortcut for getting a parameter from its name.

Parameters:: param_name – The name of a parameter of this instrument.
Returns:: The current value of the parameter.

get_component(full_name: str) → MetadatableWithName

Recursively get a component of the instrument by full_name.

Parameters:: full_name – The name of the component to get.
Returns:: The component with the given name.
Raises:: KeyError – If the component does not exist.

invalidate_cache() → None

Invalidate the cache of all parameters on the instrument. Calling this method will recursively mark the cache of all parameters on the instrument and any parameter on instrument modules as invalid.

This is useful if you have performed manual operations (e.g. using the frontpanel) which changes the state of the instrument outside QCoDeS.

This in turn means that the next snapshot of the instrument will trigger a (potentially slow) reread of all parameters of the instrument if you pass update=None to snapshot.

property label: str: Nicely formatted label of the instrument.

load_metadata(metadata: Mapping[str, Any]) → None

Load metadata into this classes metadata dictionary.

Parameters:: metadata – Metadata to load.

property name: str

Full name of the instrument

This is equivalent to full_name() for backwards compatibility.

property name_parts: list[str]: A list of all the parts of the instrument name from root_instrument() to the current InstrumentModule.

omit_delegate_attrs: ClassVar[list[str]] = []: A list of attribute names (strings) to not delegate to any other dictionary or object.

property parent: InstrumentBase: The parent instrument. By default, this is None. Any SubInstrument should subclass this to return the parent instrument.

print_readable_snapshot(update: bool = False, max_chars: int = 80) → None

Prints a readable version of the snapshot. The readable snapshot includes the name, value and unit of each parameter. A convenience function to quickly get an overview of the status of an instrument.

Parameters:

update – If True, update the state by querying the instrument. If False, just use the latest values in memory. This argument gets passed to the snapshot function.
max_chars – the maximum number of characters per line. The readable snapshot will be cropped if this value is exceeded. Defaults to 80 to be consistent with default terminal width.

property root_instrument: InstrumentBase

The topmost parent of this module.

For the root_instrument this is self.

set(param_name: str, value: Any) → None

Shortcut for setting a parameter from its name and new value.

Parameters:

param_name – The name of a parameter of this instrument.
value – The new value to set.

property short_name: str

Short name of the instrument.

For an InstrumentModule this does not include any parent names.

snapshot(update: bool | None = False) → dict[str, Any]

Decorate a snapshot dictionary with metadata. DO NOT override this method if you want metadata in the snapshot instead, override snapshot_base().

Parameters:: update – Passed to snapshot_base.
Returns:: Base snapshot.

snapshot_base(update: bool | None = False, params_to_skip_update: Sequence[str] | None = None) → dict[Any, Any]

State of the instrument as a JSON-compatible dict (everything that the custom JSON encoder class NumpyJSONEncoder supports).

Parameters:

update – If True, update the state by querying the instrument. If None update the state if known to be invalid. If False, just use the latest values in memory and never update state.
params_to_skip_update – List of parameter names that will be skipped in update even if update is True. This is useful if you have parameters that are slow to update but can be updated in a different way (as in the qdac). If you want to skip the update of certain parameters in all snapshots, use the snapshot_get attribute of those parameters instead.

Returns:

base snapshot

Return type:

dict

validate_status(verbose: bool = False) → None

Validate the values of all gettable parameters

The validation is done for all parameters that have both a get and set method.

Parameters:: verbose – If True, then information about the parameters that are being check is printed.

write(cmd: str) → None

write_raw(cmd: str) → None

parameters: dict[str, ParameterBase] = {}: All the parameters supported by this instrument. Usually populated via add_parameter().

functions: dict[str, Function] = {}: All the functions supported by this instrument. Usually populated via add_function().

submodules: dict[str, InstrumentModule | ChannelTuple] = {}: All the submodules of this instrument such as channel lists or logical groupings of parameters. Usually populated via add_submodule().

instrument_modules: dict[str, InstrumentModule] = {}: All the InstrumentModule of this instrument Usually populated via add_submodule().

log: InstrumentLoggerAdapter = get_instrument_logger(self, __name__)

metadata: dict[str, Any] = {}

class qcodes.instrument_drivers.Keithley.Keithley2450Source(parent: Keithley2450, name: str, proper_function: str)[source]

Bases: InstrumentChannel

The source module of the Keithley 2450 SMU.

Parameters:

parent
name
proper_function – This can be one of either “current” or “voltage” All parameters and methods in this submodule should only be accessible to the user if self.parent.source_function.get() == self._proper_function. We ensure this through the ‘source’ property on the main driver class which returns the proper submodule for any given function mode

Attributes:

`function_modes`
`ancestors`	Ancestors in the form of a list of `InstrumentBase`
`delegate_attr_dicts`	A list of names (strings) of dictionaries which are (or will be) attributes of `self`, whose keys should be treated as attributes of `self`.
`delegate_attr_objects`	A list of names (strings) of objects which are (or will be) attributes of `self`, whose attributes should be passed through to `self`.
`full_name`	Full name of the instrument.
`label`	Nicely formatted label of the instrument.
`name`	Full name of the instrument
`name_parts`	A list of all the parts of the instrument name from `root_instrument()` to the current `InstrumentModule`.
`omit_delegate_attrs`	A list of attribute names (strings) to not delegate to any other dictionary or object.
`parent`	The parent instrument.
`root_instrument`	The topmost parent of this module.
`short_name`	Short name of the instrument.
`parameters`	All the parameters supported by this instrument.
`functions`	All the functions supported by this instrument.
`submodules`	All the submodules of this instrument such as channel lists or logical groupings of parameters.
`instrument_modules`	All the `InstrumentModule` of this instrument Usually populated via `add_submodule()`.

Methods:

`get_sweep_axis`()
`sweep_setup`(start, stop, step_count[, ...])
`sweep_start`()	Start a sweep and return when the sweep has finished.
`sweep_reset`()
`__getitem__`(key)	Delegate instrument['name'] to parameter or function 'name'.
`__getstate__`()	Prevent pickling instruments, and give a nice error message.
`__repr__`()	Custom repr to give parent information
`add_function`(name, **kwargs)	Bind one `Function` to this instrument.
`add_parameter`(name[, parameter_class])	Bind one Parameter to this instrument.
`add_submodule`(name, submodule)	Bind one submodule to this instrument.
`ask`(cmd)
`ask_raw`(cmd)
`call`(func_name, *args)	Shortcut for calling a function from its name.
`get`(param_name)	Shortcut for getting a parameter from its name.
`get_component`(full_name)	Recursively get a component of the instrument by full_name.
`invalidate_cache`()	Invalidate the cache of all parameters on the instrument.
`load_metadata`(metadata)	Load metadata into this classes metadata dictionary.
`print_readable_snapshot`([update, max_chars])	Prints a readable version of the snapshot.
`set`(param_name, value)	Shortcut for setting a parameter from its name and new value.
`snapshot`([update])	Decorate a snapshot dictionary with metadata.
`snapshot_base`([update, params_to_skip_update])	State of the instrument as a JSON-compatible dict (everything that the custom JSON encoder class `NumpyJSONEncoder` supports).
`validate_status`([verbose])	Validate the values of all gettable parameters
`write`(cmd)
`write_raw`(cmd)

function_modes: ClassVar[dict[str, _FunctionMode]] = {'current': {'name': 'CURR', 'range_vals': <Numbers -1<=v<=1>, 'unit': 'A'}, 'voltage': {'name': 'VOLT', 'range_vals': <Numbers -200<=v<=200>, 'unit': 'V'}}

get_sweep_axis() → ndarray[source]

sweep_setup(start: float, stop: float, step_count: int, delay: float = 0, sweep_count: int = 1, range_mode: str = 'AUTO', fail_abort: str = 'ON', dual: str = 'OFF', buffer_name: str = 'defbuffer1') → None[source]

sweep_start() → None[source]: Start a sweep and return when the sweep has finished. Note: This call is blocking

sweep_reset() → None[source]

__getitem__(key: str) → Callable[..., Any] | Parameter: Delegate instrument[‘name’] to parameter or function ‘name’.

__getstate__() → None: Prevent pickling instruments, and give a nice error message.

__repr__() → str: Custom repr to give parent information

add_function(name: str, **kwargs: Any) → None

Bind one Function to this instrument.

Instrument subclasses can call this repeatedly in their __init__ for every real function of the instrument.

This functionality is meant for simple cases, principally things that map to simple commands like *RST (reset) or those with just a few arguments. It requires a fixed argument count, and positional args only.

Note

We do not recommend the usage of Function for any new driver. Function does not add any significant features over a method defined on the class.

Parameters:

name – How the Function will be stored within instrument.Functions and also how you address it using the shortcut methods: instrument.call(func_name, *args) etc.
**kwargs – constructor kwargs for Function

Raises:

KeyError – If this instrument already has a function with this name.

add_parameter(name: str, parameter_class: type[ParameterBase] | None = None, **kwargs: Any) → None

Bind one Parameter to this instrument.

Instrument subclasses can call this repeatedly in their __init__ for every real parameter of the instrument.

In this sense, parameters are the state variables of the instrument, anything the user can set and/or get.

Parameters:

name – How the parameter will be stored within parameters and also how you address it using the shortcut methods: instrument.set(param_name, value) etc.
parameter_class – You can construct the parameter out of any class. Default parameters.Parameter.
**kwargs – Constructor arguments for parameter_class.

Raises:

KeyError – If this instrument already has a parameter with this name and the parameter being replaced is not an abstract parameter.
ValueError – If there is an existing abstract parameter and the unit of the new parameter is inconsistent with the existing one.

add_submodule(name: str, submodule: InstrumentModule | ChannelTuple) → None

Bind one submodule to this instrument.

Instrument subclasses can call this repeatedly in their __init__ method for every submodule of the instrument.

Submodules can effectively be considered as instruments within the main instrument, and should at minimum be snapshottable. For example, they can be used to either store logical groupings of parameters, which may or may not be repeated, or channel lists. They should either be an instance of an InstrumentModule or a ChannelTuple.

Parameters:

name – How the submodule will be stored within instrument.submodules and also how it can be addressed.
submodule – The submodule to be stored.

Raises:

KeyError – If this instrument already contains a submodule with this name.
TypeError – If the submodule that we are trying to add is not an instance of an Metadatable object.

property ancestors: tuple[InstrumentBase, ...]

Ancestors in the form of a list of InstrumentBase

The list starts with the current module then the parent and the parents parent until the root instrument is reached.

ask(cmd: str) → str

ask_raw(cmd: str) → str

call(func_name: str, *args: Any) → Any

Shortcut for calling a function from its name.

Parameters:

func_name – The name of a function of this instrument.
*args – any arguments to the function.

Returns:

The return value of the function.

delegate_attr_dicts: ClassVar[list[str]] = ['parameters', 'functions', 'submodules']: A list of names (strings) of dictionaries which are (or will be) attributes of self, whose keys should be treated as attributes of self.

delegate_attr_objects: ClassVar[list[str]] = []: A list of names (strings) of objects which are (or will be) attributes of self, whose attributes should be passed through to self.

property full_name: str

Full name of the instrument.

For an InstrumentModule this includes all parents separated by _

get(param_name: str) → Any

Shortcut for getting a parameter from its name.

Parameters:: param_name – The name of a parameter of this instrument.
Returns:: The current value of the parameter.

get_component(full_name: str) → MetadatableWithName

Recursively get a component of the instrument by full_name.

Parameters:: full_name – The name of the component to get.
Returns:: The component with the given name.
Raises:: KeyError – If the component does not exist.

invalidate_cache() → None

Invalidate the cache of all parameters on the instrument. Calling this method will recursively mark the cache of all parameters on the instrument and any parameter on instrument modules as invalid.

This is useful if you have performed manual operations (e.g. using the frontpanel) which changes the state of the instrument outside QCoDeS.

This in turn means that the next snapshot of the instrument will trigger a (potentially slow) reread of all parameters of the instrument if you pass update=None to snapshot.

property label: str: Nicely formatted label of the instrument.

load_metadata(metadata: Mapping[str, Any]) → None

Load metadata into this classes metadata dictionary.

Parameters:: metadata – Metadata to load.

property name: str

Full name of the instrument

This is equivalent to full_name() for backwards compatibility.

property name_parts: list[str]: A list of all the parts of the instrument name from root_instrument() to the current InstrumentModule.

omit_delegate_attrs: ClassVar[list[str]] = []: A list of attribute names (strings) to not delegate to any other dictionary or object.

property parent: InstrumentBase: The parent instrument. By default, this is None. Any SubInstrument should subclass this to return the parent instrument.

print_readable_snapshot(update: bool = False, max_chars: int = 80) → None

Prints a readable version of the snapshot. The readable snapshot includes the name, value and unit of each parameter. A convenience function to quickly get an overview of the status of an instrument.

Parameters:

update – If True, update the state by querying the instrument. If False, just use the latest values in memory. This argument gets passed to the snapshot function.
max_chars – the maximum number of characters per line. The readable snapshot will be cropped if this value is exceeded. Defaults to 80 to be consistent with default terminal width.

property root_instrument: InstrumentBase

The topmost parent of this module.

For the root_instrument this is self.

set(param_name: str, value: Any) → None

Shortcut for setting a parameter from its name and new value.

Parameters:

param_name – The name of a parameter of this instrument.
value – The new value to set.

property short_name: str

Short name of the instrument.

For an InstrumentModule this does not include any parent names.

snapshot(update: bool | None = False) → dict[str, Any]

Decorate a snapshot dictionary with metadata. DO NOT override this method if you want metadata in the snapshot instead, override snapshot_base().

Parameters:: update – Passed to snapshot_base.
Returns:: Base snapshot.

snapshot_base(update: bool | None = False, params_to_skip_update: Sequence[str] | None = None) → dict[Any, Any]

State of the instrument as a JSON-compatible dict (everything that the custom JSON encoder class NumpyJSONEncoder supports).

Parameters:

update – If True, update the state by querying the instrument. If None update the state if known to be invalid. If False, just use the latest values in memory and never update state.
params_to_skip_update – List of parameter names that will be skipped in update even if update is True. This is useful if you have parameters that are slow to update but can be updated in a different way (as in the qdac). If you want to skip the update of certain parameters in all snapshots, use the snapshot_get attribute of those parameters instead.

Returns:

base snapshot

Return type:

dict

validate_status(verbose: bool = False) → None

Validate the values of all gettable parameters

The validation is done for all parameters that have both a get and set method.

Parameters:: verbose – If True, then information about the parameters that are being check is printed.

write(cmd: str) → None

write_raw(cmd: str) → None

parameters: dict[str, ParameterBase] = {}: All the parameters supported by this instrument. Usually populated via add_parameter().

functions: dict[str, Function] = {}: All the functions supported by this instrument. Usually populated via add_function().

submodules: dict[str, InstrumentModule | ChannelTuple] = {}: All the submodules of this instrument such as channel lists or logical groupings of parameters. Usually populated via add_submodule().

instrument_modules: dict[str, InstrumentModule] = {}: All the InstrumentModule of this instrument Usually populated via add_submodule().

log: InstrumentLoggerAdapter = get_instrument_logger(self, __name__)

metadata: dict[str, Any] = {}

class qcodes.instrument_drivers.Keithley.Keithley2600MeasurementStatus(value, names=None, *, module=None, qualname=None, type=None, start=1, boundary=None)[source]

Bases: StrEnum

Keeps track of measurement status.

Attributes:

`CURRENT_COMPLIANCE_ERROR`
`VOLTAGE_COMPLIANCE_ERROR`
`VOLTAGE_AND_CURRENT_COMPLIANCE_ERROR`
`NORMAL`
`COMPLIANCE_ERROR`

Methods:

`__new_member__`(*values)	values must already be of type str
`encode`([encoding, errors])	Encode the string using the codec registered for encoding.
`replace`(old, new[, count])	Return a copy with all occurrences of substring old replaced by new.
`split`([sep, maxsplit])	Return a list of the substrings in the string, using sep as the separator string.
`rsplit`([sep, maxsplit])	Return a list of the substrings in the string, using sep as the separator string.
`join`(iterable, /)	Concatenate any number of strings.
`capitalize`()	Return a capitalized version of the string.
`casefold`()	Return a version of the string suitable for caseless comparisons.
`title`()	Return a version of the string where each word is titlecased.
`center`(width[, fillchar])	Return a centered string of length width.
`count`(sub[, start[, end]])	Return the number of non-overlapping occurrences of substring sub in string S[start:end].
`expandtabs`([tabsize])	Return a copy where all tab characters are expanded using spaces.
`find`(sub[, start[, end]])	Return the lowest index in S where substring sub is found, such that sub is contained within S[start:end].
`partition`(sep, /)	Partition the string into three parts using the given separator.
`index`(sub[, start[, end]])	Return the lowest index in S where substring sub is found, such that sub is contained within S[start:end].
`ljust`(width[, fillchar])	Return a left-justified string of length width.
`lower`()	Return a copy of the string converted to lowercase.
`lstrip`([chars])	Return a copy of the string with leading whitespace removed.
`rfind`(sub[, start[, end]])	Return the highest index in S where substring sub is found, such that sub is contained within S[start:end].
`rindex`(sub[, start[, end]])	Return the highest index in S where substring sub is found, such that sub is contained within S[start:end].
`rjust`(width[, fillchar])	Return a right-justified string of length width.
`rstrip`([chars])	Return a copy of the string with trailing whitespace removed.
`rpartition`(sep, /)	Partition the string into three parts using the given separator.
`splitlines`([keepends])	Return a list of the lines in the string, breaking at line boundaries.
`strip`([chars])	Return a copy of the string with leading and trailing whitespace removed.
`swapcase`()	Convert uppercase characters to lowercase and lowercase characters to uppercase.
`translate`(table, /)	Replace each character in the string using the given translation table.
`upper`()	Return a copy of the string converted to uppercase.
`startswith`(prefix[, start[, end]])	Return True if S starts with the specified prefix, False otherwise.
`endswith`(suffix[, start[, end]])	Return True if S ends with the specified suffix, False otherwise.
`removeprefix`(prefix, /)	Return a str with the given prefix string removed if present.
`removesuffix`(suffix, /)	Return a str with the given suffix string removed if present.
`isascii`()	Return True if all characters in the string are ASCII, False otherwise.
`islower`()	Return True if the string is a lowercase string, False otherwise.
`isupper`()	Return True if the string is an uppercase string, False otherwise.
`istitle`()	Return True if the string is a title-cased string, False otherwise.
`isspace`()	Return True if the string is a whitespace string, False otherwise.
`isdecimal`()	Return True if the string is a decimal string, False otherwise.
`isdigit`()	Return True if the string is a digit string, False otherwise.
`isnumeric`()	Return True if the string is a numeric string, False otherwise.
`isalpha`()	Return True if the string is an alphabetic string, False otherwise.
`isalnum`()	Return True if the string is an alpha-numeric string, False otherwise.
`isidentifier`()	Return True if the string is a valid Python identifier, False otherwise.
`isprintable`()	Return True if the string is printable, False otherwise.
`zfill`(width, /)	Pad a numeric string with zeros on the left, to fill a field of the given width.
`format`(args, *kwargs)	Return a formatted version of S, using substitutions from args and kwargs.
`format_map`(mapping)	Return a formatted version of S, using substitutions from mapping.
`maketrans`	Return a translation table usable for str.translate().
`__dir__`()	Returns public methods and other interesting attributes.

CURRENT_COMPLIANCE_ERROR = 'Reached current compliance limit.'

VOLTAGE_COMPLIANCE_ERROR = 'Reached voltage compliance limit.'

VOLTAGE_AND_CURRENT_COMPLIANCE_ERROR = 'Reached both voltage and current compliance limits.'

NORMAL = 'No error occured.'

COMPLIANCE_ERROR = 'Reached compliance limit.'

__new_member__(*values): values must already be of type str

encode(encoding='utf-8', errors='strict')

Encode the string using the codec registered for encoding.

encoding: The encoding in which to encode the string.
errors: The error handling scheme to use for encoding errors. The default is ‘strict’ meaning that encoding errors raise a UnicodeEncodeError. Other possible values are ‘ignore’, ‘replace’ and ‘xmlcharrefreplace’ as well as any other name registered with codecs.register_error that can handle UnicodeEncodeErrors.

replace(old, new, count=-1, /)

Return a copy with all occurrences of substring old replaced by new.

count
Maximum number of occurrences to replace. -1 (the default value) means replace all occurrences.

If the optional argument count is given, only the first count occurrences are replaced.

split(sep=None, maxsplit=-1)

Return a list of the substrings in the string, using sep as the separator string.

sep
The separator used to split the string.

When set to None (the default value), will split on any whitespace character (including n r t f and spaces) and will discard empty strings from the result.

maxsplit
Maximum number of splits. -1 (the default value) means no limit.

Splitting starts at the front of the string and works to the end.

Note, str.split() is mainly useful for data that has been intentionally delimited. With natural text that includes punctuation, consider using the regular expression module.

rsplit(sep=None, maxsplit=-1)

Return a list of the substrings in the string, using sep as the separator string.

sep
The separator used to split the string.

When set to None (the default value), will split on any whitespace character (including n r t f and spaces) and will discard empty strings from the result.

maxsplit
Maximum number of splits. -1 (the default value) means no limit.

Splitting starts at the end of the string and works to the front.

join(iterable, /)

Concatenate any number of strings.

The string whose method is called is inserted in between each given string. The result is returned as a new string.

Example: ‘.’.join([‘ab’, ‘pq’, ‘rs’]) -> ‘ab.pq.rs’

capitalize()

Return a capitalized version of the string.

More specifically, make the first character have upper case and the rest lower case.

casefold(): Return a version of the string suitable for caseless comparisons.

title()

Return a version of the string where each word is titlecased.

More specifically, words start with uppercased characters and all remaining cased characters have lower case.

center(width, fillchar=' ', /)

Return a centered string of length width.

Padding is done using the specified fill character (default is a space).

count(sub[, start[, end]]) → int: Return the number of non-overlapping occurrences of substring sub in string S[start:end]. Optional arguments start and end are interpreted as in slice notation.

expandtabs(tabsize=8)

Return a copy where all tab characters are expanded using spaces.

If tabsize is not given, a tab size of 8 characters is assumed.

find(sub[, start[, end]]) → int

Return the lowest index in S where substring sub is found, such that sub is contained within S[start:end]. Optional arguments start and end are interpreted as in slice notation.

Return -1 on failure.

partition(sep, /)

Partition the string into three parts using the given separator.

This will search for the separator in the string. If the separator is found, returns a 3-tuple containing the part before the separator, the separator itself, and the part after it.

If the separator is not found, returns a 3-tuple containing the original string and two empty strings.

index(sub[, start[, end]]) → int

Return the lowest index in S where substring sub is found, such that sub is contained within S[start:end]. Optional arguments start and end are interpreted as in slice notation.

Raises ValueError when the substring is not found.

ljust(width, fillchar=' ', /)

Return a left-justified string of length width.

Padding is done using the specified fill character (default is a space).

lower(): Return a copy of the string converted to lowercase.

lstrip(chars=None, /)

Return a copy of the string with leading whitespace removed.

If chars is given and not None, remove characters in chars instead.

rfind(sub[, start[, end]]) → int

Return the highest index in S where substring sub is found, such that sub is contained within S[start:end]. Optional arguments start and end are interpreted as in slice notation.

Return -1 on failure.

rindex(sub[, start[, end]]) → int

Return the highest index in S where substring sub is found, such that sub is contained within S[start:end]. Optional arguments start and end are interpreted as in slice notation.

Raises ValueError when the substring is not found.

rjust(width, fillchar=' ', /)

Return a right-justified string of length width.

Padding is done using the specified fill character (default is a space).

rstrip(chars=None, /)

Return a copy of the string with trailing whitespace removed.

If chars is given and not None, remove characters in chars instead.

rpartition(sep, /)

Partition the string into three parts using the given separator.

This will search for the separator in the string, starting at the end. If the separator is found, returns a 3-tuple containing the part before the separator, the separator itself, and the part after it.

If the separator is not found, returns a 3-tuple containing two empty strings and the original string.

splitlines(keepends=False)

Return a list of the lines in the string, breaking at line boundaries.

Line breaks are not included in the resulting list unless keepends is given and true.

strip(chars=None, /)

Return a copy of the string with leading and trailing whitespace removed.

If chars is given and not None, remove characters in chars instead.

swapcase(): Convert uppercase characters to lowercase and lowercase characters to uppercase.

translate(table, /)

Replace each character in the string using the given translation table.

table
Translation table, which must be a mapping of Unicode ordinals to Unicode ordinals, strings, or None.

The table must implement lookup/indexing via __getitem__, for instance a dictionary or list. If this operation raises LookupError, the character is left untouched. Characters mapped to None are deleted.

upper(): Return a copy of the string converted to uppercase.

startswith(prefix[, start[, end]]) → bool: Return True if S starts with the specified prefix, False otherwise. With optional start, test S beginning at that position. With optional end, stop comparing S at that position. prefix can also be a tuple of strings to try.

endswith(suffix[, start[, end]]) → bool: Return True if S ends with the specified suffix, False otherwise. With optional start, test S beginning at that position. With optional end, stop comparing S at that position. suffix can also be a tuple of strings to try.

removeprefix(prefix, /)

Return a str with the given prefix string removed if present.

If the string starts with the prefix string, return string[len(prefix):]. Otherwise, return a copy of the original string.

removesuffix(suffix, /)

Return a str with the given suffix string removed if present.

If the string ends with the suffix string and that suffix is not empty, return string[:-len(suffix)]. Otherwise, return a copy of the original string.

isascii()

Return True if all characters in the string are ASCII, False otherwise.

ASCII characters have code points in the range U+0000-U+007F. Empty string is ASCII too.

islower()

Return True if the string is a lowercase string, False otherwise.

A string is lowercase if all cased characters in the string are lowercase and there is at least one cased character in the string.

isupper()

Return True if the string is an uppercase string, False otherwise.

A string is uppercase if all cased characters in the string are uppercase and there is at least one cased character in the string.

istitle()

Return True if the string is a title-cased string, False otherwise.

In a title-cased string, upper- and title-case characters may only follow uncased characters and lowercase characters only cased ones.

isspace()

Return True if the string is a whitespace string, False otherwise.

A string is whitespace if all characters in the string are whitespace and there is at least one character in the string.

isdecimal()

Return True if the string is a decimal string, False otherwise.

A string is a decimal string if all characters in the string are decimal and there is at least one character in the string.

isdigit()

Return True if the string is a digit string, False otherwise.

A string is a digit string if all characters in the string are digits and there is at least one character in the string.

isnumeric()

Return True if the string is a numeric string, False otherwise.

A string is numeric if all characters in the string are numeric and there is at least one character in the string.

isalpha()

Return True if the string is an alphabetic string, False otherwise.

A string is alphabetic if all characters in the string are alphabetic and there is at least one character in the string.

isalnum()

Return True if the string is an alpha-numeric string, False otherwise.

A string is alpha-numeric if all characters in the string are alpha-numeric and there is at least one character in the string.

isidentifier()

Return True if the string is a valid Python identifier, False otherwise.

Call keyword.iskeyword(s) to test whether string s is a reserved identifier, such as “def” or “class”.

isprintable()

Return True if the string is printable, False otherwise.

A string is printable if all of its characters are considered printable in repr() or if it is empty.

zfill(width, /)

Pad a numeric string with zeros on the left, to fill a field of the given width.

The string is never truncated.

format(*args, **kwargs) → str: Return a formatted version of S, using substitutions from args and kwargs. The substitutions are identified by braces (‘{’ and ‘}’).

format_map(mapping) → str: Return a formatted version of S, using substitutions from mapping. The substitutions are identified by braces (‘{’ and ‘}’).

static maketrans()

Return a translation table usable for str.translate().

If there is only one argument, it must be a dictionary mapping Unicode ordinals (integers) or characters to Unicode ordinals, strings or None. Character keys will be then converted to ordinals. If there are two arguments, they must be strings of equal length, and in the resulting dictionary, each character in x will be mapped to the character at the same position in y. If there is a third argument, it must be a string, whose characters will be mapped to None in the result.

__dir__(): Returns public methods and other interesting attributes.

qcodes.instrument_drivers.Keithley.Keithley26xx(*args, **kwargs)

All Keithley 26xx SMUs supported by QCoDeS.

class qcodes.instrument_drivers.Keithley.Keithley2601B(name: str, address: str, **kwargs: Any)[source]

Bases: Keithley2600

QCoDeS driver for the Keithley 2601B Source-Meter

Parameters:

name – Name to use internally in QCoDeS
address – VISA resource address
**kwargs – kwargs are forwarded to base class.

Methods:

`__del__`()	Close the instrument and remove its instance record.
`__getitem__`(key)	Delegate instrument['name'] to parameter or function 'name'.
`__getstate__`()	Prevent pickling instruments, and give a nice error message.
`__repr__`()	Simplified repr giving just the class and name.
`add_function`(name, **kwargs)	Bind one `Function` to this instrument.
`add_parameter`(name[, parameter_class])	Bind one Parameter to this instrument.
`add_submodule`(name, submodule)	Bind one submodule to this instrument.
`ask`(cmd)	Override of normal ask.
`ask_raw`(cmd)	Low-level interface to `visa_handle.ask`.
`call`(func_name, *args)	Shortcut for calling a function from its name.
`close`()	Disconnect and irreversibly tear down the instrument.
`close_all`()	Try to close all instruments registered in `_all_instruments` This is handy for use with atexit to ensure that all instruments are closed when a python session is closed.
`connect_message`([idn_param, begin_time])	Print a standard message on initial connection to an instrument.
`device_clear`()	Clear the buffers of the device
`display_clear`()	This function clears the display, but also leaves it in user mode
`display_normal`()	Set the display to the default mode
`exist`(name[, instrument_class])	Check if an instrument with a given names exists (i.e. is already instantiated).
`exit_key`()	Get back the normal screen after an error: send an EXIT key press event
`find_instrument`(name[, instrument_class])	Find an existing instrument by name.
`get`(param_name)	Shortcut for getting a parameter from its name.
`get_component`(full_name)	Recursively get a component of the instrument by full_name.
`get_idn`()	Parse a standard VISA `*IDN?` response into an ID dict.
`instances`()	Get all currently defined instances of this instrument class.
`invalidate_cache`()	Invalidate the cache of all parameters on the instrument.
`is_valid`(instr_instance)	Check if a given instance of an instrument is valid: if an instrument has been closed, its instance is not longer a "valid" instrument.
`load_metadata`(metadata)	Load metadata into this classes metadata dictionary.
`print_readable_snapshot`([update, max_chars])	Prints a readable version of the snapshot.
`record_instance`(instance)	Record (a weak ref to) an instance in a class's instance list.
`remove_instance`(instance)	Remove a particular instance from the record.
`reset`()	Reset instrument to factory defaults.
`set`(param_name, value)	Shortcut for setting a parameter from its name and new value.
`set_address`(address)	Set the address for this instrument.
`set_terminator`(terminator)	Change the read terminator to use.
`snapshot`([update])	Decorate a snapshot dictionary with metadata.
`snapshot_base`([update, params_to_skip_update])	State of the instrument as a JSON-compatible dict (everything that the custom JSON encoder class `NumpyJSONEncoder` supports).
`validate_status`([verbose])	Validate the values of all gettable parameters
`write`(cmd)	Write a command string with NO response to the hardware.
`write_raw`(cmd)	Low-level interface to `visa_handle.write`.

Attributes:

`ancestors`	Ancestors in the form of a list of `InstrumentBase`
`delegate_attr_dicts`	A list of names (strings) of dictionaries which are (or will be) attributes of `self`, whose keys should be treated as attributes of `self`.
`delegate_attr_objects`	A list of names (strings) of objects which are (or will be) attributes of `self`, whose attributes should be passed through to `self`.
`full_name`	Full name of the instrument.
`label`	Nicely formatted label of the instrument.
`name`	Full name of the instrument
`name_parts`	A list of all the parts of the instrument name from `root_instrument()` to the current `InstrumentModule`.
`omit_delegate_attrs`	A list of attribute names (strings) to not delegate to any other dictionary or object.
`parent`	The parent instrument.
`root_instrument`	The topmost parent of this module.
`short_name`	Short name of the instrument.
`visa_handle`	The VISA resource used by this instrument.
`resource_manager`	The VISA resource manager used by this instrument.
`parameters`	All the parameters supported by this instrument.
`functions`	All the functions supported by this instrument.
`submodules`	All the submodules of this instrument such as channel lists or logical groupings of parameters.
`instrument_modules`	All the `InstrumentModule` of this instrument Usually populated via `add_submodule()`.

__del__() → None: Close the instrument and remove its instance record.

__getitem__(key: str) → Callable[..., Any] | Parameter: Delegate instrument[‘name’] to parameter or function ‘name’.

__getstate__() → None: Prevent pickling instruments, and give a nice error message.

__repr__() → str: Simplified repr giving just the class and name.

add_function(name: str, **kwargs: Any) → None

Bind one Function to this instrument.

Instrument subclasses can call this repeatedly in their __init__ for every real function of the instrument.

This functionality is meant for simple cases, principally things that map to simple commands like *RST (reset) or those with just a few arguments. It requires a fixed argument count, and positional args only.

Note

We do not recommend the usage of Function for any new driver. Function does not add any significant features over a method defined on the class.

Parameters:

name – How the Function will be stored within instrument.Functions and also how you address it using the shortcut methods: instrument.call(func_name, *args) etc.
**kwargs – constructor kwargs for Function

Raises:

KeyError – If this instrument already has a function with this name.

add_parameter(name: str, parameter_class: type[ParameterBase] | None = None, **kwargs: Any) → None

Bind one Parameter to this instrument.

Instrument subclasses can call this repeatedly in their __init__ for every real parameter of the instrument.

In this sense, parameters are the state variables of the instrument, anything the user can set and/or get.

Parameters:

name – How the parameter will be stored within parameters and also how you address it using the shortcut methods: instrument.set(param_name, value) etc.
parameter_class – You can construct the parameter out of any class. Default parameters.Parameter.
**kwargs – Constructor arguments for parameter_class.

Raises:

KeyError – If this instrument already has a parameter with this name and the parameter being replaced is not an abstract parameter.
ValueError – If there is an existing abstract parameter and the unit of the new parameter is inconsistent with the existing one.

add_submodule(name: str, submodule: InstrumentModule | ChannelTuple) → None

Bind one submodule to this instrument.

Instrument subclasses can call this repeatedly in their __init__ method for every submodule of the instrument.

Submodules can effectively be considered as instruments within the main instrument, and should at minimum be snapshottable. For example, they can be used to either store logical groupings of parameters, which may or may not be repeated, or channel lists. They should either be an instance of an InstrumentModule or a ChannelTuple.

Parameters:

name – How the submodule will be stored within instrument.submodules and also how it can be addressed.
submodule – The submodule to be stored.

Raises:

KeyError – If this instrument already contains a submodule with this name.
TypeError – If the submodule that we are trying to add is not an instance of an Metadatable object.

property ancestors: tuple[InstrumentBase, ...]

Ancestors in the form of a list of InstrumentBase

The list starts with the current module then the parent and the parents parent until the root instrument is reached.

ask(cmd: str) → str: Override of normal ask. This is important, since queries to the instrument must be wrapped in ‘print()’

ask_raw(cmd: str) → str

Low-level interface to visa_handle.ask.

Parameters:: cmd – The command to send to the instrument.
Returns:: The instrument’s response.
Return type:: str

call(func_name: str, *args: Any) → Any

Shortcut for calling a function from its name.

Parameters:

func_name – The name of a function of this instrument.
*args – any arguments to the function.

Returns:

The return value of the function.

close() → None: Disconnect and irreversibly tear down the instrument.

classmethod close_all() → None

Try to close all instruments registered in _all_instruments This is handy for use with atexit to ensure that all instruments are closed when a python session is closed.

Examples

>>> atexit.register(qc.Instrument.close_all())

connect_message(idn_param: str = 'IDN', begin_time: float | None = None) → None

Print a standard message on initial connection to an instrument.

Parameters:

idn_param – Name of parameter that returns ID dict. Default IDN.
begin_time – time.time() when init started. Default is self._t0, set at start of Instrument.__init__.

delegate_attr_dicts: ClassVar[list[str]] = ['parameters', 'functions', 'submodules']: A list of names (strings) of dictionaries which are (or will be) attributes of self, whose keys should be treated as attributes of self.

delegate_attr_objects: ClassVar[list[str]] = []: A list of names (strings) of objects which are (or will be) attributes of self, whose attributes should be passed through to self.

device_clear() → None: Clear the buffers of the device

display_clear() → None: This function clears the display, but also leaves it in user mode

display_normal() → None: Set the display to the default mode

static exist(name: str, instrument_class: type[Instrument] | None = None) → bool

Check if an instrument with a given names exists (i.e. is already instantiated).

Parameters:

name – Name of the instrument.
instrument_class – The type of instrument you are looking for.

exit_key() → None: Get back the normal screen after an error: send an EXIT key press event

classmethod find_instrument(name: str, instrument_class: type[T] | None = None) → T | Instrument

Find an existing instrument by name.

Parameters:

name – Name of the instrument.
instrument_class – The type of instrument you are looking for.

Returns:

The instrument found.

Raises:

KeyError – If no instrument of that name was found, or if its reference is invalid (dead).
TypeError – If a specific class was requested but a different type was found.

property full_name: str

Full name of the instrument.

For an InstrumentModule this includes all parents separated by _

get(param_name: str) → Any

Shortcut for getting a parameter from its name.

Parameters:: param_name – The name of a parameter of this instrument.
Returns:: The current value of the parameter.

get_component(full_name: str) → MetadatableWithName

Recursively get a component of the instrument by full_name.

Parameters:: full_name – The name of the component to get.
Returns:: The component with the given name.
Raises:: KeyError – If the component does not exist.

get_idn() → dict[str, str | None]

Parse a standard VISA *IDN? response into an ID dict.

Even though this is the VISA standard, it applies to various other types as well, such as IPInstruments, so it is included here in the Instrument base class.

Override this if your instrument does not support *IDN? or returns a nonstandard IDN string. This string is supposed to be a comma-separated list of vendor, model, serial, and firmware, but semicolon and colon are also common separators so we accept them here as well.

Returns:: A dict containing vendor, model, serial, and firmware.

classmethod instances() → list[T]

Get all currently defined instances of this instrument class.

You can use this to get the objects back if you lose track of them, and it’s also used by the test system to find objects to test against.

Returns:: A list of instances.

invalidate_cache() → None

Invalidate the cache of all parameters on the instrument. Calling this method will recursively mark the cache of all parameters on the instrument and any parameter on instrument modules as invalid.

This is useful if you have performed manual operations (e.g. using the frontpanel) which changes the state of the instrument outside QCoDeS.

This in turn means that the next snapshot of the instrument will trigger a (potentially slow) reread of all parameters of the instrument if you pass update=None to snapshot.

static is_valid(instr_instance: Instrument) → bool

Check if a given instance of an instrument is valid: if an instrument has been closed, its instance is not longer a “valid” instrument.

Parameters:: instr_instance – Instance of an Instrument class or its subclass.

property label: str: Nicely formatted label of the instrument.

load_metadata(metadata: Mapping[str, Any]) → None

Load metadata into this classes metadata dictionary.

Parameters:: metadata – Metadata to load.

property name: str

Full name of the instrument

This is equivalent to full_name() for backwards compatibility.

property name_parts: list[str]: A list of all the parts of the instrument name from root_instrument() to the current InstrumentModule.

omit_delegate_attrs: ClassVar[list[str]] = []: A list of attribute names (strings) to not delegate to any other dictionary or object.

property parent: InstrumentBase | None: The parent instrument. By default, this is None. Any SubInstrument should subclass this to return the parent instrument.

print_readable_snapshot(update: bool = False, max_chars: int = 80) → None

Prints a readable version of the snapshot. The readable snapshot includes the name, value and unit of each parameter. A convenience function to quickly get an overview of the status of an instrument.

Parameters:

update – If True, update the state by querying the instrument. If False, just use the latest values in memory. This argument gets passed to the snapshot function.
max_chars – the maximum number of characters per line. The readable snapshot will be cropped if this value is exceeded. Defaults to 80 to be consistent with default terminal width.

classmethod record_instance(instance: Instrument) → None

Record (a weak ref to) an instance in a class’s instance list.

Also records the instance in list of all instruments, and verifies that there are no other instruments with the same name.

This method is called after initialization of the instrument is completed.

Parameters:: instance – Instance to record.
Raises:: KeyError – If another instance with the same name is already present.

classmethod remove_instance(instance: Instrument) → None

Remove a particular instance from the record.

Parameters:: instance – The instance to remove

reset() → None: Reset instrument to factory defaults. This resets both channels.

property root_instrument: InstrumentBase

The topmost parent of this module.

For the root_instrument this is self.

set(param_name: str, value: Any) → None

Shortcut for setting a parameter from its name and new value.

Parameters:

param_name – The name of a parameter of this instrument.
value – The new value to set.

set_address(address: str) → None

Set the address for this instrument.

Parameters:: address – The visa resource name to use to connect. The address should be the actual address and just that. If you wish to change the backend for VISA, use the self.visalib attribute (and then call this function).

set_terminator(terminator: str | None) → None

Change the read terminator to use.

Parameters:: terminator – Character(s) to look for at the end of a read and to end each write command with. eg. \r\n. If None the terminator will not be set.

property short_name: str

Short name of the instrument.

For an InstrumentModule this does not include any parent names.

snapshot(update: bool | None = False) → dict[str, Any]

Decorate a snapshot dictionary with metadata. DO NOT override this method if you want metadata in the snapshot instead, override snapshot_base().

Parameters:: update – Passed to snapshot_base.
Returns:: Base snapshot.

snapshot_base(update: bool | None = True, params_to_skip_update: Sequence[str] | None = None) → dict[Any, Any]

State of the instrument as a JSON-compatible dict (everything that the custom JSON encoder class NumpyJSONEncoder supports).

Parameters:

update – If True, update the state by querying the instrument. If None only update if the state is known to be invalid. If False, just use the latest values in memory and never update.
params_to_skip_update – List of parameter names that will be skipped in update even if update is True. This is useful if you have parameters that are slow to update but can be updated in a different way (as in the qdac). If you want to skip the update of certain parameters in all snapshots, use the snapshot_get attribute of those parameters instead.

Returns:

base snapshot

Return type:

dict

validate_status(verbose: bool = False) → None

Validate the values of all gettable parameters

The validation is done for all parameters that have both a get and set method.

Parameters:: verbose – If True, then information about the parameters that are being check is printed.

write(cmd: str) → None

Write a command string with NO response to the hardware.

Subclasses that transform cmd should override this method, and in it call super().write(new_cmd). Subclasses that define a new hardware communication should instead override write_raw.

Parameters:: cmd – The string to send to the instrument.
Raises:: Exception – Wraps any underlying exception with extra context, including the command and the instrument.

write_raw(cmd: str) → None

Low-level interface to visa_handle.write.

Parameters:: cmd – The command to send to the instrument.

channels: list[Keithley2600Channel] = []

visabackend: str = visabackend

visa_handle: pyvisa.resources.MessageBasedResource = visa_handle: The VISA resource used by this instrument.

visalib: str | None = visalib

parameters: dict[str, ParameterBase] = {}: All the parameters supported by this instrument. Usually populated via add_parameter().

functions: dict[str, Function] = {}: All the functions supported by this instrument. Usually populated via add_function().

submodules: dict[str, InstrumentModule | ChannelTuple] = {}: All the submodules of this instrument such as channel lists or logical groupings of parameters. Usually populated via add_submodule().

instrument_modules: dict[str, InstrumentModule] = {}: All the InstrumentModule of this instrument Usually populated via add_submodule().

log: InstrumentLoggerAdapter = get_instrument_logger(self, __name__)

metadata: dict[str, Any] = {}

resource_manager = resource_manager: The VISA resource manager used by this instrument.

class qcodes.instrument_drivers.Keithley.Keithley2602A(name: str, address: str, **kwargs: Any)[source]

Bases: Keithley2600

QCoDeS driver for the Keithley 2602A Source-Meter

Parameters:

name – Name to use internally in QCoDeS
address – VISA resource address
**kwargs – kwargs are forwarded to base class.

Methods:

`__del__`()	Close the instrument and remove its instance record.
`__getitem__`(key)	Delegate instrument['name'] to parameter or function 'name'.
`__getstate__`()	Prevent pickling instruments, and give a nice error message.
`__repr__`()	Simplified repr giving just the class and name.
`add_function`(name, **kwargs)	Bind one `Function` to this instrument.
`add_parameter`(name[, parameter_class])	Bind one Parameter to this instrument.
`add_submodule`(name, submodule)	Bind one submodule to this instrument.
`ask`(cmd)	Override of normal ask.
`ask_raw`(cmd)	Low-level interface to `visa_handle.ask`.
`call`(func_name, *args)	Shortcut for calling a function from its name.
`close`()	Disconnect and irreversibly tear down the instrument.
`close_all`()	Try to close all instruments registered in `_all_instruments` This is handy for use with atexit to ensure that all instruments are closed when a python session is closed.
`connect_message`([idn_param, begin_time])	Print a standard message on initial connection to an instrument.
`device_clear`()	Clear the buffers of the device
`display_clear`()	This function clears the display, but also leaves it in user mode
`display_normal`()	Set the display to the default mode
`exist`(name[, instrument_class])	Check if an instrument with a given names exists (i.e. is already instantiated).
`exit_key`()	Get back the normal screen after an error: send an EXIT key press event
`find_instrument`(name[, instrument_class])	Find an existing instrument by name.
`get`(param_name)	Shortcut for getting a parameter from its name.
`get_component`(full_name)	Recursively get a component of the instrument by full_name.
`get_idn`()	Parse a standard VISA `*IDN?` response into an ID dict.
`instances`()	Get all currently defined instances of this instrument class.
`invalidate_cache`()	Invalidate the cache of all parameters on the instrument.
`is_valid`(instr_instance)	Check if a given instance of an instrument is valid: if an instrument has been closed, its instance is not longer a "valid" instrument.
`load_metadata`(metadata)	Load metadata into this classes metadata dictionary.
`print_readable_snapshot`([update, max_chars])	Prints a readable version of the snapshot.
`record_instance`(instance)	Record (a weak ref to) an instance in a class's instance list.
`remove_instance`(instance)	Remove a particular instance from the record.
`reset`()	Reset instrument to factory defaults.
`set`(param_name, value)	Shortcut for setting a parameter from its name and new value.
`set_address`(address)	Set the address for this instrument.
`set_terminator`(terminator)	Change the read terminator to use.
`snapshot`([update])	Decorate a snapshot dictionary with metadata.
`snapshot_base`([update, params_to_skip_update])	State of the instrument as a JSON-compatible dict (everything that the custom JSON encoder class `NumpyJSONEncoder` supports).
`validate_status`([verbose])	Validate the values of all gettable parameters
`write`(cmd)	Write a command string with NO response to the hardware.
`write_raw`(cmd)	Low-level interface to `visa_handle.write`.

Attributes:

`ancestors`	Ancestors in the form of a list of `InstrumentBase`
`delegate_attr_dicts`	A list of names (strings) of dictionaries which are (or will be) attributes of `self`, whose keys should be treated as attributes of `self`.
`delegate_attr_objects`	A list of names (strings) of objects which are (or will be) attributes of `self`, whose attributes should be passed through to `self`.
`full_name`	Full name of the instrument.
`label`	Nicely formatted label of the instrument.
`name`	Full name of the instrument
`name_parts`	A list of all the parts of the instrument name from `root_instrument()` to the current `InstrumentModule`.
`omit_delegate_attrs`	A list of attribute names (strings) to not delegate to any other dictionary or object.
`parent`	The parent instrument.
`root_instrument`	The topmost parent of this module.
`short_name`	Short name of the instrument.
`visa_handle`	The VISA resource used by this instrument.
`resource_manager`	The VISA resource manager used by this instrument.
`parameters`	All the parameters supported by this instrument.
`functions`	All the functions supported by this instrument.
`submodules`	All the submodules of this instrument such as channel lists or logical groupings of parameters.
`instrument_modules`	All the `InstrumentModule` of this instrument Usually populated via `add_submodule()`.

__del__() → None: Close the instrument and remove its instance record.

__getitem__(key: str) → Callable[..., Any] | Parameter: Delegate instrument[‘name’] to parameter or function ‘name’.

__getstate__() → None: Prevent pickling instruments, and give a nice error message.

__repr__() → str: Simplified repr giving just the class and name.

add_function(name: str, **kwargs: Any) → None

Bind one Function to this instrument.

Instrument subclasses can call this repeatedly in their __init__ for every real function of the instrument.

This functionality is meant for simple cases, principally things that map to simple commands like *RST (reset) or those with just a few arguments. It requires a fixed argument count, and positional args only.

Note

We do not recommend the usage of Function for any new driver. Function does not add any significant features over a method defined on the class.

Parameters:

name – How the Function will be stored within instrument.Functions and also how you address it using the shortcut methods: instrument.call(func_name, *args) etc.
**kwargs – constructor kwargs for Function

Raises:

KeyError – If this instrument already has a function with this name.

add_parameter(name: str, parameter_class: type[ParameterBase] | None = None, **kwargs: Any) → None

Bind one Parameter to this instrument.

Instrument subclasses can call this repeatedly in their __init__ for every real parameter of the instrument.

In this sense, parameters are the state variables of the instrument, anything the user can set and/or get.

Parameters:

name – How the parameter will be stored within parameters and also how you address it using the shortcut methods: instrument.set(param_name, value) etc.
parameter_class – You can construct the parameter out of any class. Default parameters.Parameter.
**kwargs – Constructor arguments for parameter_class.

Raises:

KeyError – If this instrument already has a parameter with this name and the parameter being replaced is not an abstract parameter.
ValueError – If there is an existing abstract parameter and the unit of the new parameter is inconsistent with the existing one.

add_submodule(name: str, submodule: InstrumentModule | ChannelTuple) → None

Bind one submodule to this instrument.

Instrument subclasses can call this repeatedly in their __init__ method for every submodule of the instrument.

Submodules can effectively be considered as instruments within the main instrument, and should at minimum be snapshottable. For example, they can be used to either store logical groupings of parameters, which may or may not be repeated, or channel lists. They should either be an instance of an InstrumentModule or a ChannelTuple.

Parameters:

name – How the submodule will be stored within instrument.submodules and also how it can be addressed.
submodule – The submodule to be stored.

Raises:

KeyError – If this instrument already contains a submodule with this name.
TypeError – If the submodule that we are trying to add is not an instance of an Metadatable object.

property ancestors: tuple[InstrumentBase, ...]

Ancestors in the form of a list of InstrumentBase

The list starts with the current module then the parent and the parents parent until the root instrument is reached.

ask(cmd: str) → str: Override of normal ask. This is important, since queries to the instrument must be wrapped in ‘print()’

ask_raw(cmd: str) → str

Low-level interface to visa_handle.ask.

Parameters:: cmd – The command to send to the instrument.
Returns:: The instrument’s response.
Return type:: str

call(func_name: str, *args: Any) → Any

Shortcut for calling a function from its name.

Parameters:

func_name – The name of a function of this instrument.
*args – any arguments to the function.

Returns:

The return value of the function.

close() → None: Disconnect and irreversibly tear down the instrument.

classmethod close_all() → None

Try to close all instruments registered in _all_instruments This is handy for use with atexit to ensure that all instruments are closed when a python session is closed.

Examples

>>> atexit.register(qc.Instrument.close_all())

connect_message(idn_param: str = 'IDN', begin_time: float | None = None) → None

Print a standard message on initial connection to an instrument.

Parameters:

idn_param – Name of parameter that returns ID dict. Default IDN.
begin_time – time.time() when init started. Default is self._t0, set at start of Instrument.__init__.

delegate_attr_dicts: ClassVar[list[str]] = ['parameters', 'functions', 'submodules']: A list of names (strings) of dictionaries which are (or will be) attributes of self, whose keys should be treated as attributes of self.

delegate_attr_objects: ClassVar[list[str]] = []: A list of names (strings) of objects which are (or will be) attributes of self, whose attributes should be passed through to self.

device_clear() → None: Clear the buffers of the device

display_clear() → None: This function clears the display, but also leaves it in user mode

display_normal() → None: Set the display to the default mode

static exist(name: str, instrument_class: type[Instrument] | None = None) → bool

Check if an instrument with a given names exists (i.e. is already instantiated).

Parameters:

name – Name of the instrument.
instrument_class – The type of instrument you are looking for.

exit_key() → None: Get back the normal screen after an error: send an EXIT key press event

classmethod find_instrument(name: str, instrument_class: type[T] | None = None) → T | Instrument

Find an existing instrument by name.

Parameters:

name – Name of the instrument.
instrument_class – The type of instrument you are looking for.

Returns:

The instrument found.

Raises:

KeyError – If no instrument of that name was found, or if its reference is invalid (dead).
TypeError – If a specific class was requested but a different type was found.

property full_name: str

Full name of the instrument.

For an InstrumentModule this includes all parents separated by _

get(param_name: str) → Any

Shortcut for getting a parameter from its name.

Parameters:: param_name – The name of a parameter of this instrument.
Returns:: The current value of the parameter.

get_component(full_name: str) → MetadatableWithName

Recursively get a component of the instrument by full_name.

Parameters:: full_name – The name of the component to get.
Returns:: The component with the given name.
Raises:: KeyError – If the component does not exist.

get_idn() → dict[str, str | None]

Parse a standard VISA *IDN? response into an ID dict.

Even though this is the VISA standard, it applies to various other types as well, such as IPInstruments, so it is included here in the Instrument base class.

Override this if your instrument does not support *IDN? or returns a nonstandard IDN string. This string is supposed to be a comma-separated list of vendor, model, serial, and firmware, but semicolon and colon are also common separators so we accept them here as well.

Returns:: A dict containing vendor, model, serial, and firmware.

classmethod instances() → list[T]

Get all currently defined instances of this instrument class.

You can use this to get the objects back if you lose track of them, and it’s also used by the test system to find objects to test against.

Returns:: A list of instances.

invalidate_cache() → None

Invalidate the cache of all parameters on the instrument. Calling this method will recursively mark the cache of all parameters on the instrument and any parameter on instrument modules as invalid.

This is useful if you have performed manual operations (e.g. using the frontpanel) which changes the state of the instrument outside QCoDeS.

This in turn means that the next snapshot of the instrument will trigger a (potentially slow) reread of all parameters of the instrument if you pass update=None to snapshot.

static is_valid(instr_instance: Instrument) → bool

Check if a given instance of an instrument is valid: if an instrument has been closed, its instance is not longer a “valid” instrument.

Parameters:: instr_instance – Instance of an Instrument class or its subclass.

property label: str: Nicely formatted label of the instrument.

load_metadata(metadata: Mapping[str, Any]) → None

Load metadata into this classes metadata dictionary.

Parameters:: metadata – Metadata to load.

property name: str

Full name of the instrument

This is equivalent to full_name() for backwards compatibility.

property name_parts: list[str]: A list of all the parts of the instrument name from root_instrument() to the current InstrumentModule.

omit_delegate_attrs: ClassVar[list[str]] = []: A list of attribute names (strings) to not delegate to any other dictionary or object.

property parent: InstrumentBase | None: The parent instrument. By default, this is None. Any SubInstrument should subclass this to return the parent instrument.

print_readable_snapshot(update: bool = False, max_chars: int = 80) → None

Prints a readable version of the snapshot. The readable snapshot includes the name, value and unit of each parameter. A convenience function to quickly get an overview of the status of an instrument.

Parameters:

update – If True, update the state by querying the instrument. If False, just use the latest values in memory. This argument gets passed to the snapshot function.
max_chars – the maximum number of characters per line. The readable snapshot will be cropped if this value is exceeded. Defaults to 80 to be consistent with default terminal width.

classmethod record_instance(instance: Instrument) → None

Record (a weak ref to) an instance in a class’s instance list.

Also records the instance in list of all instruments, and verifies that there are no other instruments with the same name.

This method is called after initialization of the instrument is completed.

Parameters:: instance – Instance to record.
Raises:: KeyError – If another instance with the same name is already present.

classmethod remove_instance(instance: Instrument) → None

Remove a particular instance from the record.

Parameters:: instance – The instance to remove

reset() → None: Reset instrument to factory defaults. This resets both channels.

property root_instrument: InstrumentBase

The topmost parent of this module.

For the root_instrument this is self.

set(param_name: str, value: Any) → None

Shortcut for setting a parameter from its name and new value.

Parameters:

param_name – The name of a parameter of this instrument.
value – The new value to set.

set_address(address: str) → None

Set the address for this instrument.

Parameters:: address – The visa resource name to use to connect. The address should be the actual address and just that. If you wish to change the backend for VISA, use the self.visalib attribute (and then call this function).

set_terminator(terminator: str | None) → None

Change the read terminator to use.

Parameters:: terminator – Character(s) to look for at the end of a read and to end each write command with. eg. \r\n. If None the terminator will not be set.

property short_name: str

Short name of the instrument.

For an InstrumentModule this does not include any parent names.

snapshot(update: bool | None = False) → dict[str, Any]

Decorate a snapshot dictionary with metadata. DO NOT override this method if you want metadata in the snapshot instead, override snapshot_base().

Parameters:: update – Passed to snapshot_base.
Returns:: Base snapshot.

snapshot_base(update: bool | None = True, params_to_skip_update: Sequence[str] | None = None) → dict[Any, Any]

State of the instrument as a JSON-compatible dict (everything that the custom JSON encoder class NumpyJSONEncoder supports).

Parameters:

update – If True, update the state by querying the instrument. If None only update if the state is known to be invalid. If False, just use the latest values in memory and never update.
params_to_skip_update – List of parameter names that will be skipped in update even if update is True. This is useful if you have parameters that are slow to update but can be updated in a different way (as in the qdac). If you want to skip the update of certain parameters in all snapshots, use the snapshot_get attribute of those parameters instead.

Returns:

base snapshot

Return type:

dict

validate_status(verbose: bool = False) → None

Validate the values of all gettable parameters

The validation is done for all parameters that have both a get and set method.

Parameters:: verbose – If True, then information about the parameters that are being check is printed.

write(cmd: str) → None

Write a command string with NO response to the hardware.

Subclasses that transform cmd should override this method, and in it call super().write(new_cmd). Subclasses that define a new hardware communication should instead override write_raw.

Parameters:: cmd – The string to send to the instrument.
Raises:: Exception – Wraps any underlying exception with extra context, including the command and the instrument.

write_raw(cmd: str) → None

Low-level interface to visa_handle.write.

Parameters:: cmd – The command to send to the instrument.

channels: list[Keithley2600Channel] = []

visabackend: str = visabackend

visa_handle: pyvisa.resources.MessageBasedResource = visa_handle: The VISA resource used by this instrument.

visalib: str | None = visalib

parameters: dict[str, ParameterBase] = {}: All the parameters supported by this instrument. Usually populated via add_parameter().

functions: dict[str, Function] = {}: All the functions supported by this instrument. Usually populated via add_function().

submodules: dict[str, InstrumentModule | ChannelTuple] = {}: All the submodules of this instrument such as channel lists or logical groupings of parameters. Usually populated via add_submodule().

instrument_modules: dict[str, InstrumentModule] = {}: All the InstrumentModule of this instrument Usually populated via add_submodule().

log: InstrumentLoggerAdapter = get_instrument_logger(self, __name__)

metadata: dict[str, Any] = {}

resource_manager = resource_manager: The VISA resource manager used by this instrument.

class qcodes.instrument_drivers.Keithley.Keithley2602B(name: str, address: str, **kwargs: Any)[source]

Bases: Keithley2600

QCoDeS driver for the Keithley 2602B Source-Meter

Parameters:

name – Name to use internally in QCoDeS
address – VISA resource address
**kwargs – kwargs are forwarded to base class.

Methods:

`__del__`()	Close the instrument and remove its instance record.
`__getitem__`(key)	Delegate instrument['name'] to parameter or function 'name'.
`__getstate__`()	Prevent pickling instruments, and give a nice error message.
`__repr__`()	Simplified repr giving just the class and name.
`add_function`(name, **kwargs)	Bind one `Function` to this instrument.
`add_parameter`(name[, parameter_class])	Bind one Parameter to this instrument.
`add_submodule`(name, submodule)	Bind one submodule to this instrument.
`ask`(cmd)	Override of normal ask.
`ask_raw`(cmd)	Low-level interface to `visa_handle.ask`.
`call`(func_name, *args)	Shortcut for calling a function from its name.
`close`()	Disconnect and irreversibly tear down the instrument.
`close_all`()	Try to close all instruments registered in `_all_instruments` This is handy for use with atexit to ensure that all instruments are closed when a python session is closed.
`connect_message`([idn_param, begin_time])	Print a standard message on initial connection to an instrument.
`device_clear`()	Clear the buffers of the device
`display_clear`()	This function clears the display, but also leaves it in user mode
`display_normal`()	Set the display to the default mode
`exist`(name[, instrument_class])	Check if an instrument with a given names exists (i.e. is already instantiated).
`exit_key`()	Get back the normal screen after an error: send an EXIT key press event
`find_instrument`(name[, instrument_class])	Find an existing instrument by name.
`get`(param_name)	Shortcut for getting a parameter from its name.
`get_component`(full_name)	Recursively get a component of the instrument by full_name.
`get_idn`()	Parse a standard VISA `*IDN?` response into an ID dict.
`instances`()	Get all currently defined instances of this instrument class.
`invalidate_cache`()	Invalidate the cache of all parameters on the instrument.
`is_valid`(instr_instance)	Check if a given instance of an instrument is valid: if an instrument has been closed, its instance is not longer a "valid" instrument.
`load_metadata`(metadata)	Load metadata into this classes metadata dictionary.
`print_readable_snapshot`([update, max_chars])	Prints a readable version of the snapshot.
`record_instance`(instance)	Record (a weak ref to) an instance in a class's instance list.
`remove_instance`(instance)	Remove a particular instance from the record.
`reset`()	Reset instrument to factory defaults.
`set`(param_name, value)	Shortcut for setting a parameter from its name and new value.
`set_address`(address)	Set the address for this instrument.
`set_terminator`(terminator)	Change the read terminator to use.
`snapshot`([update])	Decorate a snapshot dictionary with metadata.
`snapshot_base`([update, params_to_skip_update])	State of the instrument as a JSON-compatible dict (everything that the custom JSON encoder class `NumpyJSONEncoder` supports).
`validate_status`([verbose])	Validate the values of all gettable parameters
`write`(cmd)	Write a command string with NO response to the hardware.
`write_raw`(cmd)	Low-level interface to `visa_handle.write`.

Attributes:

`ancestors`	Ancestors in the form of a list of `InstrumentBase`
`delegate_attr_dicts`	A list of names (strings) of dictionaries which are (or will be) attributes of `self`, whose keys should be treated as attributes of `self`.
`delegate_attr_objects`	A list of names (strings) of objects which are (or will be) attributes of `self`, whose attributes should be passed through to `self`.
`full_name`	Full name of the instrument.
`label`	Nicely formatted label of the instrument.
`name`	Full name of the instrument
`name_parts`	A list of all the parts of the instrument name from `root_instrument()` to the current `InstrumentModule`.
`omit_delegate_attrs`	A list of attribute names (strings) to not delegate to any other dictionary or object.
`parent`	The parent instrument.
`root_instrument`	The topmost parent of this module.
`short_name`	Short name of the instrument.
`visa_handle`	The VISA resource used by this instrument.
`resource_manager`	The VISA resource manager used by this instrument.
`parameters`	All the parameters supported by this instrument.
`functions`	All the functions supported by this instrument.
`submodules`	All the submodules of this instrument such as channel lists or logical groupings of parameters.
`instrument_modules`	All the `InstrumentModule` of this instrument Usually populated via `add_submodule()`.

__del__() → None: Close the instrument and remove its instance record.

__getitem__(key: str) → Callable[..., Any] | Parameter: Delegate instrument[‘name’] to parameter or function ‘name’.

__getstate__() → None: Prevent pickling instruments, and give a nice error message.

__repr__() → str: Simplified repr giving just the class and name.

add_function(name: str, **kwargs: Any) → None

Bind one Function to this instrument.

Instrument subclasses can call this repeatedly in their __init__ for every real function of the instrument.

This functionality is meant for simple cases, principally things that map to simple commands like *RST (reset) or those with just a few arguments. It requires a fixed argument count, and positional args only.

Note

We do not recommend the usage of Function for any new driver. Function does not add any significant features over a method defined on the class.

Parameters:

name – How the Function will be stored within instrument.Functions and also how you address it using the shortcut methods: instrument.call(func_name, *args) etc.
**kwargs – constructor kwargs for Function

Raises:

KeyError – If this instrument already has a function with this name.

add_parameter(name: str, parameter_class: type[ParameterBase] | None = None, **kwargs: Any) → None

Bind one Parameter to this instrument.

Instrument subclasses can call this repeatedly in their __init__ for every real parameter of the instrument.

In this sense, parameters are the state variables of the instrument, anything the user can set and/or get.

Parameters:

name – How the parameter will be stored within parameters and also how you address it using the shortcut methods: instrument.set(param_name, value) etc.
parameter_class – You can construct the parameter out of any class. Default parameters.Parameter.
**kwargs – Constructor arguments for parameter_class.

Raises:

KeyError – If this instrument already has a parameter with this name and the parameter being replaced is not an abstract parameter.
ValueError – If there is an existing abstract parameter and the unit of the new parameter is inconsistent with the existing one.

add_submodule(name: str, submodule: InstrumentModule | ChannelTuple) → None

Bind one submodule to this instrument.

Instrument subclasses can call this repeatedly in their __init__ method for every submodule of the instrument.

Submodules can effectively be considered as instruments within the main instrument, and should at minimum be snapshottable. For example, they can be used to either store logical groupings of parameters, which may or may not be repeated, or channel lists. They should either be an instance of an InstrumentModule or a ChannelTuple.

Parameters:

name – How the submodule will be stored within instrument.submodules and also how it can be addressed.
submodule – The submodule to be stored.

Raises:

KeyError – If this instrument already contains a submodule with this name.
TypeError – If the submodule that we are trying to add is not an instance of an Metadatable object.

property ancestors: tuple[InstrumentBase, ...]

Ancestors in the form of a list of InstrumentBase

The list starts with the current module then the parent and the parents parent until the root instrument is reached.

ask(cmd: str) → str: Override of normal ask. This is important, since queries to the instrument must be wrapped in ‘print()’

ask_raw(cmd: str) → str

Low-level interface to visa_handle.ask.

Parameters:: cmd – The command to send to the instrument.
Returns:: The instrument’s response.
Return type:: str

call(func_name: str, *args: Any) → Any

Shortcut for calling a function from its name.

Parameters:

func_name – The name of a function of this instrument.
*args – any arguments to the function.

Returns:

The return value of the function.

close() → None: Disconnect and irreversibly tear down the instrument.

classmethod close_all() → None

Try to close all instruments registered in _all_instruments This is handy for use with atexit to ensure that all instruments are closed when a python session is closed.

Examples

>>> atexit.register(qc.Instrument.close_all())

connect_message(idn_param: str = 'IDN', begin_time: float | None = None) → None

Print a standard message on initial connection to an instrument.

Parameters:

idn_param – Name of parameter that returns ID dict. Default IDN.
begin_time – time.time() when init started. Default is self._t0, set at start of Instrument.__init__.

delegate_attr_dicts: ClassVar[list[str]] = ['parameters', 'functions', 'submodules']: A list of names (strings) of dictionaries which are (or will be) attributes of self, whose keys should be treated as attributes of self.

delegate_attr_objects: ClassVar[list[str]] = []: A list of names (strings) of objects which are (or will be) attributes of self, whose attributes should be passed through to self.

device_clear() → None: Clear the buffers of the device

display_clear() → None: This function clears the display, but also leaves it in user mode

display_normal() → None: Set the display to the default mode

static exist(name: str, instrument_class: type[Instrument] | None = None) → bool

Check if an instrument with a given names exists (i.e. is already instantiated).

Parameters:

name – Name of the instrument.
instrument_class – The type of instrument you are looking for.

exit_key() → None: Get back the normal screen after an error: send an EXIT key press event

classmethod find_instrument(name: str, instrument_class: type[T] | None = None) → T | Instrument

Find an existing instrument by name.

Parameters:

name – Name of the instrument.
instrument_class – The type of instrument you are looking for.

Returns:

The instrument found.

Raises:

KeyError – If no instrument of that name was found, or if its reference is invalid (dead).
TypeError – If a specific class was requested but a different type was found.

property full_name: str

Full name of the instrument.

For an InstrumentModule this includes all parents separated by _

get(param_name: str) → Any

Shortcut for getting a parameter from its name.

Parameters:: param_name – The name of a parameter of this instrument.
Returns:: The current value of the parameter.

get_component(full_name: str) → MetadatableWithName

Recursively get a component of the instrument by full_name.

Parameters:: full_name – The name of the component to get.
Returns:: The component with the given name.
Raises:: KeyError – If the component does not exist.

get_idn() → dict[str, str | None]

Parse a standard VISA *IDN? response into an ID dict.

Even though this is the VISA standard, it applies to various other types as well, such as IPInstruments, so it is included here in the Instrument base class.

Override this if your instrument does not support *IDN? or returns a nonstandard IDN string. This string is supposed to be a comma-separated list of vendor, model, serial, and firmware, but semicolon and colon are also common separators so we accept them here as well.

Returns:: A dict containing vendor, model, serial, and firmware.

classmethod instances() → list[T]

Get all currently defined instances of this instrument class.

You can use this to get the objects back if you lose track of them, and it’s also used by the test system to find objects to test against.

Returns:: A list of instances.

invalidate_cache() → None

Invalidate the cache of all parameters on the instrument. Calling this method will recursively mark the cache of all parameters on the instrument and any parameter on instrument modules as invalid.

This is useful if you have performed manual operations (e.g. using the frontpanel) which changes the state of the instrument outside QCoDeS.

This in turn means that the next snapshot of the instrument will trigger a (potentially slow) reread of all parameters of the instrument if you pass update=None to snapshot.

static is_valid(instr_instance: Instrument) → bool

Check if a given instance of an instrument is valid: if an instrument has been closed, its instance is not longer a “valid” instrument.

Parameters:: instr_instance – Instance of an Instrument class or its subclass.

property label: str: Nicely formatted label of the instrument.

load_metadata(metadata: Mapping[str, Any]) → None

Load metadata into this classes metadata dictionary.

Parameters:: metadata – Metadata to load.

property name: str

Full name of the instrument

This is equivalent to full_name() for backwards compatibility.

property name_parts: list[str]: A list of all the parts of the instrument name from root_instrument() to the current InstrumentModule.

omit_delegate_attrs: ClassVar[list[str]] = []: A list of attribute names (strings) to not delegate to any other dictionary or object.

property parent: InstrumentBase | None: The parent instrument. By default, this is None. Any SubInstrument should subclass this to return the parent instrument.

print_readable_snapshot(update: bool = False, max_chars: int = 80) → None

Prints a readable version of the snapshot. The readable snapshot includes the name, value and unit of each parameter. A convenience function to quickly get an overview of the status of an instrument.

Parameters:

update – If True, update the state by querying the instrument. If False, just use the latest values in memory. This argument gets passed to the snapshot function.
max_chars – the maximum number of characters per line. The readable snapshot will be cropped if this value is exceeded. Defaults to 80 to be consistent with default terminal width.

classmethod record_instance(instance: Instrument) → None

Record (a weak ref to) an instance in a class’s instance list.

Also records the instance in list of all instruments, and verifies that there are no other instruments with the same name.

This method is called after initialization of the instrument is completed.

Parameters:: instance – Instance to record.
Raises:: KeyError – If another instance with the same name is already present.

classmethod remove_instance(instance: Instrument) → None

Remove a particular instance from the record.

Parameters:: instance – The instance to remove

reset() → None: Reset instrument to factory defaults. This resets both channels.

property root_instrument: InstrumentBase

The topmost parent of this module.

For the root_instrument this is self.

set(param_name: str, value: Any) → None

Shortcut for setting a parameter from its name and new value.

Parameters:

param_name – The name of a parameter of this instrument.
value – The new value to set.

set_address(address: str) → None

Set the address for this instrument.

Parameters:: address – The visa resource name to use to connect. The address should be the actual address and just that. If you wish to change the backend for VISA, use the self.visalib attribute (and then call this function).

set_terminator(terminator: str | None) → None

Change the read terminator to use.

Parameters:: terminator – Character(s) to look for at the end of a read and to end each write command with. eg. \r\n. If None the terminator will not be set.

property short_name: str

Short name of the instrument.

For an InstrumentModule this does not include any parent names.

snapshot(update: bool | None = False) → dict[str, Any]

Decorate a snapshot dictionary with metadata. DO NOT override this method if you want metadata in the snapshot instead, override snapshot_base().

Parameters:: update – Passed to snapshot_base.
Returns:: Base snapshot.

snapshot_base(update: bool | None = True, params_to_skip_update: Sequence[str] | None = None) → dict[Any, Any]

State of the instrument as a JSON-compatible dict (everything that the custom JSON encoder class NumpyJSONEncoder supports).

Parameters:

update – If True, update the state by querying the instrument. If None only update if the state is known to be invalid. If False, just use the latest values in memory and never update.
params_to_skip_update – List of parameter names that will be skipped in update even if update is True. This is useful if you have parameters that are slow to update but can be updated in a different way (as in the qdac). If you want to skip the update of certain parameters in all snapshots, use the snapshot_get attribute of those parameters instead.

Returns:

base snapshot

Return type:

dict

validate_status(verbose: bool = False) → None

Validate the values of all gettable parameters

The validation is done for all parameters that have both a get and set method.

Parameters:: verbose – If True, then information about the parameters that are being check is printed.

write(cmd: str) → None

Write a command string with NO response to the hardware.

Subclasses that transform cmd should override this method, and in it call super().write(new_cmd). Subclasses that define a new hardware communication should instead override write_raw.

Parameters:: cmd – The string to send to the instrument.
Raises:: Exception – Wraps any underlying exception with extra context, including the command and the instrument.

write_raw(cmd: str) → None

Low-level interface to visa_handle.write.

Parameters:: cmd – The command to send to the instrument.

channels: list[Keithley2600Channel] = []

visabackend: str = visabackend

visa_handle: pyvisa.resources.MessageBasedResource = visa_handle: The VISA resource used by this instrument.

visalib: str | None = visalib

parameters: dict[str, ParameterBase] = {}: All the parameters supported by this instrument. Usually populated via add_parameter().

functions: dict[str, Function] = {}: All the functions supported by this instrument. Usually populated via add_function().

submodules: dict[str, InstrumentModule | ChannelTuple] = {}: All the submodules of this instrument such as channel lists or logical groupings of parameters. Usually populated via add_submodule().

instrument_modules: dict[str, InstrumentModule] = {}: All the InstrumentModule of this instrument Usually populated via add_submodule().

log: InstrumentLoggerAdapter = get_instrument_logger(self, __name__)

metadata: dict[str, Any] = {}

resource_manager = resource_manager: The VISA resource manager used by this instrument.

class qcodes.instrument_drivers.Keithley.Keithley2604B(name: str, address: str, **kwargs: Any)[source]

Bases: Keithley2600

QCoDeS driver for the Keithley 2604B Source-Meter

Parameters:

name – Name to use internally in QCoDeS
address – VISA resource address
**kwargs – kwargs are forwarded to base class.

Methods:

`__del__`()	Close the instrument and remove its instance record.
`__getitem__`(key)	Delegate instrument['name'] to parameter or function 'name'.
`__getstate__`()	Prevent pickling instruments, and give a nice error message.
`__repr__`()	Simplified repr giving just the class and name.
`add_function`(name, **kwargs)	Bind one `Function` to this instrument.
`add_parameter`(name[, parameter_class])	Bind one Parameter to this instrument.
`add_submodule`(name, submodule)	Bind one submodule to this instrument.
`ask`(cmd)	Override of normal ask.
`ask_raw`(cmd)	Low-level interface to `visa_handle.ask`.
`call`(func_name, *args)	Shortcut for calling a function from its name.
`close`()	Disconnect and irreversibly tear down the instrument.
`close_all`()	Try to close all instruments registered in `_all_instruments` This is handy for use with atexit to ensure that all instruments are closed when a python session is closed.
`connect_message`([idn_param, begin_time])	Print a standard message on initial connection to an instrument.
`device_clear`()	Clear the buffers of the device
`display_clear`()	This function clears the display, but also leaves it in user mode
`display_normal`()	Set the display to the default mode
`exist`(name[, instrument_class])	Check if an instrument with a given names exists (i.e. is already instantiated).
`exit_key`()	Get back the normal screen after an error: send an EXIT key press event
`find_instrument`(name[, instrument_class])	Find an existing instrument by name.
`get`(param_name)	Shortcut for getting a parameter from its name.
`get_component`(full_name)	Recursively get a component of the instrument by full_name.
`get_idn`()	Parse a standard VISA `*IDN?` response into an ID dict.
`instances`()	Get all currently defined instances of this instrument class.
`invalidate_cache`()	Invalidate the cache of all parameters on the instrument.
`is_valid`(instr_instance)	Check if a given instance of an instrument is valid: if an instrument has been closed, its instance is not longer a "valid" instrument.
`load_metadata`(metadata)	Load metadata into this classes metadata dictionary.
`print_readable_snapshot`([update, max_chars])	Prints a readable version of the snapshot.
`record_instance`(instance)	Record (a weak ref to) an instance in a class's instance list.
`remove_instance`(instance)	Remove a particular instance from the record.
`reset`()	Reset instrument to factory defaults.
`set`(param_name, value)	Shortcut for setting a parameter from its name and new value.
`set_address`(address)	Set the address for this instrument.
`set_terminator`(terminator)	Change the read terminator to use.
`snapshot`([update])	Decorate a snapshot dictionary with metadata.
`snapshot_base`([update, params_to_skip_update])	State of the instrument as a JSON-compatible dict (everything that the custom JSON encoder class `NumpyJSONEncoder` supports).
`validate_status`([verbose])	Validate the values of all gettable parameters
`write`(cmd)	Write a command string with NO response to the hardware.
`write_raw`(cmd)	Low-level interface to `visa_handle.write`.

Attributes:

`ancestors`	Ancestors in the form of a list of `InstrumentBase`
`delegate_attr_dicts`	A list of names (strings) of dictionaries which are (or will be) attributes of `self`, whose keys should be treated as attributes of `self`.
`delegate_attr_objects`	A list of names (strings) of objects which are (or will be) attributes of `self`, whose attributes should be passed through to `self`.
`full_name`	Full name of the instrument.
`label`	Nicely formatted label of the instrument.
`name`	Full name of the instrument
`name_parts`	A list of all the parts of the instrument name from `root_instrument()` to the current `InstrumentModule`.
`omit_delegate_attrs`	A list of attribute names (strings) to not delegate to any other dictionary or object.
`parent`	The parent instrument.
`root_instrument`	The topmost parent of this module.
`short_name`	Short name of the instrument.
`visa_handle`	The VISA resource used by this instrument.
`resource_manager`	The VISA resource manager used by this instrument.
`parameters`	All the parameters supported by this instrument.
`functions`	All the functions supported by this instrument.
`submodules`	All the submodules of this instrument such as channel lists or logical groupings of parameters.
`instrument_modules`	All the `InstrumentModule` of this instrument Usually populated via `add_submodule()`.

__del__() → None: Close the instrument and remove its instance record.

__getitem__(key: str) → Callable[..., Any] | Parameter: Delegate instrument[‘name’] to parameter or function ‘name’.

__getstate__() → None: Prevent pickling instruments, and give a nice error message.

__repr__() → str: Simplified repr giving just the class and name.

add_function(name: str, **kwargs: Any) → None

Bind one Function to this instrument.

Instrument subclasses can call this repeatedly in their __init__ for every real function of the instrument.

This functionality is meant for simple cases, principally things that map to simple commands like *RST (reset) or those with just a few arguments. It requires a fixed argument count, and positional args only.

Note

We do not recommend the usage of Function for any new driver. Function does not add any significant features over a method defined on the class.

Parameters:

name – How the Function will be stored within instrument.Functions and also how you address it using the shortcut methods: instrument.call(func_name, *args) etc.
**kwargs – constructor kwargs for Function

Raises:

KeyError – If this instrument already has a function with this name.

add_parameter(name: str, parameter_class: type[ParameterBase] | None = None, **kwargs: Any) → None

Bind one Parameter to this instrument.

Instrument subclasses can call this repeatedly in their __init__ for every real parameter of the instrument.

In this sense, parameters are the state variables of the instrument, anything the user can set and/or get.

Parameters:

name – How the parameter will be stored within parameters and also how you address it using the shortcut methods: instrument.set(param_name, value) etc.
parameter_class – You can construct the parameter out of any class. Default parameters.Parameter.
**kwargs – Constructor arguments for parameter_class.

Raises:

KeyError – If this instrument already has a parameter with this name and the parameter being replaced is not an abstract parameter.
ValueError – If there is an existing abstract parameter and the unit of the new parameter is inconsistent with the existing one.

add_submodule(name: str, submodule: InstrumentModule | ChannelTuple) → None

Bind one submodule to this instrument.

Instrument subclasses can call this repeatedly in their __init__ method for every submodule of the instrument.

Submodules can effectively be considered as instruments within the main instrument, and should at minimum be snapshottable. For example, they can be used to either store logical groupings of parameters, which may or may not be repeated, or channel lists. They should either be an instance of an InstrumentModule or a ChannelTuple.

Parameters:

name – How the submodule will be stored within instrument.submodules and also how it can be addressed.
submodule – The submodule to be stored.

Raises:

KeyError – If this instrument already contains a submodule with this name.
TypeError – If the submodule that we are trying to add is not an instance of an Metadatable object.

property ancestors: tuple[InstrumentBase, ...]

Ancestors in the form of a list of InstrumentBase

The list starts with the current module then the parent and the parents parent until the root instrument is reached.

ask(cmd: str) → str: Override of normal ask. This is important, since queries to the instrument must be wrapped in ‘print()’

ask_raw(cmd: str) → str

Low-level interface to visa_handle.ask.

Parameters:: cmd – The command to send to the instrument.
Returns:: The instrument’s response.
Return type:: str

call(func_name: str, *args: Any) → Any

Shortcut for calling a function from its name.

Parameters:

func_name – The name of a function of this instrument.
*args – any arguments to the function.

Returns:

The return value of the function.

close() → None: Disconnect and irreversibly tear down the instrument.

classmethod close_all() → None

Try to close all instruments registered in _all_instruments This is handy for use with atexit to ensure that all instruments are closed when a python session is closed.

Examples

>>> atexit.register(qc.Instrument.close_all())

connect_message(idn_param: str = 'IDN', begin_time: float | None = None) → None

Print a standard message on initial connection to an instrument.

Parameters:

idn_param – Name of parameter that returns ID dict. Default IDN.
begin_time – time.time() when init started. Default is self._t0, set at start of Instrument.__init__.

delegate_attr_dicts: ClassVar[list[str]] = ['parameters', 'functions', 'submodules']: A list of names (strings) of dictionaries which are (or will be) attributes of self, whose keys should be treated as attributes of self.

delegate_attr_objects: ClassVar[list[str]] = []: A list of names (strings) of objects which are (or will be) attributes of self, whose attributes should be passed through to self.

device_clear() → None: Clear the buffers of the device

display_clear() → None: This function clears the display, but also leaves it in user mode

display_normal() → None: Set the display to the default mode

static exist(name: str, instrument_class: type[Instrument] | None = None) → bool

Check if an instrument with a given names exists (i.e. is already instantiated).

Parameters:

name – Name of the instrument.
instrument_class – The type of instrument you are looking for.

exit_key() → None: Get back the normal screen after an error: send an EXIT key press event

classmethod find_instrument(name: str, instrument_class: type[T] | None = None) → T | Instrument

Find an existing instrument by name.

Parameters:

name – Name of the instrument.
instrument_class – The type of instrument you are looking for.

Returns:

The instrument found.

Raises:

KeyError – If no instrument of that name was found, or if its reference is invalid (dead).
TypeError – If a specific class was requested but a different type was found.

property full_name: str

Full name of the instrument.

For an InstrumentModule this includes all parents separated by _

get(param_name: str) → Any

Shortcut for getting a parameter from its name.

Parameters:: param_name – The name of a parameter of this instrument.
Returns:: The current value of the parameter.

get_component(full_name: str) → MetadatableWithName

Recursively get a component of the instrument by full_name.

Parameters:: full_name – The name of the component to get.
Returns:: The component with the given name.
Raises:: KeyError – If the component does not exist.

get_idn() → dict[str, str | None]

Parse a standard VISA *IDN? response into an ID dict.

Even though this is the VISA standard, it applies to various other types as well, such as IPInstruments, so it is included here in the Instrument base class.

Override this if your instrument does not support *IDN? or returns a nonstandard IDN string. This string is supposed to be a comma-separated list of vendor, model, serial, and firmware, but semicolon and colon are also common separators so we accept them here as well.

Returns:: A dict containing vendor, model, serial, and firmware.

classmethod instances() → list[T]

Get all currently defined instances of this instrument class.

You can use this to get the objects back if you lose track of them, and it’s also used by the test system to find objects to test against.

Returns:: A list of instances.

invalidate_cache() → None

Invalidate the cache of all parameters on the instrument. Calling this method will recursively mark the cache of all parameters on the instrument and any parameter on instrument modules as invalid.

This is useful if you have performed manual operations (e.g. using the frontpanel) which changes the state of the instrument outside QCoDeS.

This in turn means that the next snapshot of the instrument will trigger a (potentially slow) reread of all parameters of the instrument if you pass update=None to snapshot.

static is_valid(instr_instance: Instrument) → bool

Check if a given instance of an instrument is valid: if an instrument has been closed, its instance is not longer a “valid” instrument.

Parameters:: instr_instance – Instance of an Instrument class or its subclass.

property label: str: Nicely formatted label of the instrument.

load_metadata(metadata: Mapping[str, Any]) → None

Load metadata into this classes metadata dictionary.

Parameters:: metadata – Metadata to load.

property name: str

Full name of the instrument

This is equivalent to full_name() for backwards compatibility.

property name_parts: list[str]: A list of all the parts of the instrument name from root_instrument() to the current InstrumentModule.

omit_delegate_attrs: ClassVar[list[str]] = []: A list of attribute names (strings) to not delegate to any other dictionary or object.

property parent: InstrumentBase | None: The parent instrument. By default, this is None. Any SubInstrument should subclass this to return the parent instrument.

print_readable_snapshot(update: bool = False, max_chars: int = 80) → None

Prints a readable version of the snapshot. The readable snapshot includes the name, value and unit of each parameter. A convenience function to quickly get an overview of the status of an instrument.

Parameters:

update – If True, update the state by querying the instrument. If False, just use the latest values in memory. This argument gets passed to the snapshot function.
max_chars – the maximum number of characters per line. The readable snapshot will be cropped if this value is exceeded. Defaults to 80 to be consistent with default terminal width.

classmethod record_instance(instance: Instrument) → None

Record (a weak ref to) an instance in a class’s instance list.

Also records the instance in list of all instruments, and verifies that there are no other instruments with the same name.

This method is called after initialization of the instrument is completed.

Parameters:: instance – Instance to record.
Raises:: KeyError – If another instance with the same name is already present.

classmethod remove_instance(instance: Instrument) → None

Remove a particular instance from the record.

Parameters:: instance – The instance to remove

reset() → None: Reset instrument to factory defaults. This resets both channels.

property root_instrument: InstrumentBase

The topmost parent of this module.

For the root_instrument this is self.

set(param_name: str, value: Any) → None

Shortcut for setting a parameter from its name and new value.

Parameters:

param_name – The name of a parameter of this instrument.
value – The new value to set.

set_address(address: str) → None

Set the address for this instrument.

Parameters:: address – The visa resource name to use to connect. The address should be the actual address and just that. If you wish to change the backend for VISA, use the self.visalib attribute (and then call this function).

set_terminator(terminator: str | None) → None

Change the read terminator to use.

Parameters:: terminator – Character(s) to look for at the end of a read and to end each write command with. eg. \r\n. If None the terminator will not be set.

property short_name: str

Short name of the instrument.

For an InstrumentModule this does not include any parent names.

snapshot(update: bool | None = False) → dict[str, Any]

Decorate a snapshot dictionary with metadata. DO NOT override this method if you want metadata in the snapshot instead, override snapshot_base().

Parameters:: update – Passed to snapshot_base.
Returns:: Base snapshot.

snapshot_base(update: bool | None = True, params_to_skip_update: Sequence[str] | None = None) → dict[Any, Any]

State of the instrument as a JSON-compatible dict (everything that the custom JSON encoder class NumpyJSONEncoder supports).

Parameters:

update – If True, update the state by querying the instrument. If None only update if the state is known to be invalid. If False, just use the latest values in memory and never update.
params_to_skip_update – List of parameter names that will be skipped in update even if update is True. This is useful if you have parameters that are slow to update but can be updated in a different way (as in the qdac). If you want to skip the update of certain parameters in all snapshots, use the snapshot_get attribute of those parameters instead.

Returns:

base snapshot

Return type:

dict

validate_status(verbose: bool = False) → None

Validate the values of all gettable parameters

The validation is done for all parameters that have both a get and set method.

Parameters:: verbose – If True, then information about the parameters that are being check is printed.

write(cmd: str) → None

Write a command string with NO response to the hardware.

Subclasses that transform cmd should override this method, and in it call super().write(new_cmd). Subclasses that define a new hardware communication should instead override write_raw.

Parameters:: cmd – The string to send to the instrument.
Raises:: Exception – Wraps any underlying exception with extra context, including the command and the instrument.

write_raw(cmd: str) → None

Low-level interface to visa_handle.write.

Parameters:: cmd – The command to send to the instrument.

channels: list[Keithley2600Channel] = []

visabackend: str = visabackend

visa_handle: pyvisa.resources.MessageBasedResource = visa_handle: The VISA resource used by this instrument.

visalib: str | None = visalib

parameters: dict[str, ParameterBase] = {}: All the parameters supported by this instrument. Usually populated via add_parameter().

functions: dict[str, Function] = {}: All the functions supported by this instrument. Usually populated via add_function().

submodules: dict[str, InstrumentModule | ChannelTuple] = {}: All the submodules of this instrument such as channel lists or logical groupings of parameters. Usually populated via add_submodule().

instrument_modules: dict[str, InstrumentModule] = {}: All the InstrumentModule of this instrument Usually populated via add_submodule().

log: InstrumentLoggerAdapter = get_instrument_logger(self, __name__)

metadata: dict[str, Any] = {}

resource_manager = resource_manager: The VISA resource manager used by this instrument.

class qcodes.instrument_drivers.Keithley.Keithley2611B(name: str, address: str, **kwargs: Any)[source]

Bases: Keithley2600

QCoDeS driver for the Keithley 2611B Source-Meter

Parameters:

name – Name to use internally in QCoDeS
address – VISA resource address
**kwargs – kwargs are forwarded to base class.

Methods:

`__del__`()	Close the instrument and remove its instance record.
`__getitem__`(key)	Delegate instrument['name'] to parameter or function 'name'.
`__getstate__`()	Prevent pickling instruments, and give a nice error message.
`__repr__`()	Simplified repr giving just the class and name.
`add_function`(name, **kwargs)	Bind one `Function` to this instrument.
`add_parameter`(name[, parameter_class])	Bind one Parameter to this instrument.
`add_submodule`(name, submodule)	Bind one submodule to this instrument.
`ask`(cmd)	Override of normal ask.
`ask_raw`(cmd)	Low-level interface to `visa_handle.ask`.
`call`(func_name, *args)	Shortcut for calling a function from its name.
`close`()	Disconnect and irreversibly tear down the instrument.
`close_all`()	Try to close all instruments registered in `_all_instruments` This is handy for use with atexit to ensure that all instruments are closed when a python session is closed.
`connect_message`([idn_param, begin_time])	Print a standard message on initial connection to an instrument.
`device_clear`()	Clear the buffers of the device
`display_clear`()	This function clears the display, but also leaves it in user mode
`display_normal`()	Set the display to the default mode
`exist`(name[, instrument_class])	Check if an instrument with a given names exists (i.e. is already instantiated).
`exit_key`()	Get back the normal screen after an error: send an EXIT key press event
`find_instrument`(name[, instrument_class])	Find an existing instrument by name.
`get`(param_name)	Shortcut for getting a parameter from its name.
`get_component`(full_name)	Recursively get a component of the instrument by full_name.
`get_idn`()	Parse a standard VISA `*IDN?` response into an ID dict.
`instances`()	Get all currently defined instances of this instrument class.
`invalidate_cache`()	Invalidate the cache of all parameters on the instrument.
`is_valid`(instr_instance)	Check if a given instance of an instrument is valid: if an instrument has been closed, its instance is not longer a "valid" instrument.
`load_metadata`(metadata)	Load metadata into this classes metadata dictionary.
`print_readable_snapshot`([update, max_chars])	Prints a readable version of the snapshot.
`record_instance`(instance)	Record (a weak ref to) an instance in a class's instance list.
`remove_instance`(instance)	Remove a particular instance from the record.
`reset`()	Reset instrument to factory defaults.
`set`(param_name, value)	Shortcut for setting a parameter from its name and new value.
`set_address`(address)	Set the address for this instrument.
`set_terminator`(terminator)	Change the read terminator to use.
`snapshot`([update])	Decorate a snapshot dictionary with metadata.
`snapshot_base`([update, params_to_skip_update])	State of the instrument as a JSON-compatible dict (everything that the custom JSON encoder class `NumpyJSONEncoder` supports).
`validate_status`([verbose])	Validate the values of all gettable parameters
`write`(cmd)	Write a command string with NO response to the hardware.
`write_raw`(cmd)	Low-level interface to `visa_handle.write`.

Attributes:

`ancestors`	Ancestors in the form of a list of `InstrumentBase`
`delegate_attr_dicts`	A list of names (strings) of dictionaries which are (or will be) attributes of `self`, whose keys should be treated as attributes of `self`.
`delegate_attr_objects`	A list of names (strings) of objects which are (or will be) attributes of `self`, whose attributes should be passed through to `self`.
`full_name`	Full name of the instrument.
`label`	Nicely formatted label of the instrument.
`name`	Full name of the instrument
`name_parts`	A list of all the parts of the instrument name from `root_instrument()` to the current `InstrumentModule`.
`omit_delegate_attrs`	A list of attribute names (strings) to not delegate to any other dictionary or object.
`parent`	The parent instrument.
`root_instrument`	The topmost parent of this module.
`short_name`	Short name of the instrument.
`visa_handle`	The VISA resource used by this instrument.
`resource_manager`	The VISA resource manager used by this instrument.
`parameters`	All the parameters supported by this instrument.
`functions`	All the functions supported by this instrument.
`submodules`	All the submodules of this instrument such as channel lists or logical groupings of parameters.
`instrument_modules`	All the `InstrumentModule` of this instrument Usually populated via `add_submodule()`.

__del__() → None: Close the instrument and remove its instance record.

__getitem__(key: str) → Callable[..., Any] | Parameter: Delegate instrument[‘name’] to parameter or function ‘name’.

__getstate__() → None: Prevent pickling instruments, and give a nice error message.

__repr__() → str: Simplified repr giving just the class and name.

add_function(name: str, **kwargs: Any) → None

Bind one Function to this instrument.

Instrument subclasses can call this repeatedly in their __init__ for every real function of the instrument.

This functionality is meant for simple cases, principally things that map to simple commands like *RST (reset) or those with just a few arguments. It requires a fixed argument count, and positional args only.

Note

We do not recommend the usage of Function for any new driver. Function does not add any significant features over a method defined on the class.

Parameters:

name – How the Function will be stored within instrument.Functions and also how you address it using the shortcut methods: instrument.call(func_name, *args) etc.
**kwargs – constructor kwargs for Function

Raises:

KeyError – If this instrument already has a function with this name.

add_parameter(name: str, parameter_class: type[ParameterBase] | None = None, **kwargs: Any) → None

Bind one Parameter to this instrument.

Instrument subclasses can call this repeatedly in their __init__ for every real parameter of the instrument.

In this sense, parameters are the state variables of the instrument, anything the user can set and/or get.

Parameters:

name – How the parameter will be stored within parameters and also how you address it using the shortcut methods: instrument.set(param_name, value) etc.
parameter_class – You can construct the parameter out of any class. Default parameters.Parameter.
**kwargs – Constructor arguments for parameter_class.

Raises:

KeyError – If this instrument already has a parameter with this name and the parameter being replaced is not an abstract parameter.
ValueError – If there is an existing abstract parameter and the unit of the new parameter is inconsistent with the existing one.

add_submodule(name: str, submodule: InstrumentModule | ChannelTuple) → None

Bind one submodule to this instrument.

Instrument subclasses can call this repeatedly in their __init__ method for every submodule of the instrument.

Submodules can effectively be considered as instruments within the main instrument, and should at minimum be snapshottable. For example, they can be used to either store logical groupings of parameters, which may or may not be repeated, or channel lists. They should either be an instance of an InstrumentModule or a ChannelTuple.

Parameters:

name – How the submodule will be stored within instrument.submodules and also how it can be addressed.
submodule – The submodule to be stored.

Raises:

KeyError – If this instrument already contains a submodule with this name.
TypeError – If the submodule that we are trying to add is not an instance of an Metadatable object.

property ancestors: tuple[InstrumentBase, ...]

Ancestors in the form of a list of InstrumentBase

The list starts with the current module then the parent and the parents parent until the root instrument is reached.

ask(cmd: str) → str: Override of normal ask. This is important, since queries to the instrument must be wrapped in ‘print()’

ask_raw(cmd: str) → str

Low-level interface to visa_handle.ask.

Parameters:: cmd – The command to send to the instrument.
Returns:: The instrument’s response.
Return type:: str

call(func_name: str, *args: Any) → Any

Shortcut for calling a function from its name.

Parameters:

func_name – The name of a function of this instrument.
*args – any arguments to the function.

Returns:

The return value of the function.

close() → None: Disconnect and irreversibly tear down the instrument.

classmethod close_all() → None

Try to close all instruments registered in _all_instruments This is handy for use with atexit to ensure that all instruments are closed when a python session is closed.

Examples

>>> atexit.register(qc.Instrument.close_all())

connect_message(idn_param: str = 'IDN', begin_time: float | None = None) → None

Print a standard message on initial connection to an instrument.

Parameters:

idn_param – Name of parameter that returns ID dict. Default IDN.
begin_time – time.time() when init started. Default is self._t0, set at start of Instrument.__init__.

delegate_attr_dicts: ClassVar[list[str]] = ['parameters', 'functions', 'submodules']: A list of names (strings) of dictionaries which are (or will be) attributes of self, whose keys should be treated as attributes of self.

delegate_attr_objects: ClassVar[list[str]] = []: A list of names (strings) of objects which are (or will be) attributes of self, whose attributes should be passed through to self.

device_clear() → None: Clear the buffers of the device

display_clear() → None: This function clears the display, but also leaves it in user mode

display_normal() → None: Set the display to the default mode

static exist(name: str, instrument_class: type[Instrument] | None = None) → bool

Check if an instrument with a given names exists (i.e. is already instantiated).

Parameters:

name – Name of the instrument.
instrument_class – The type of instrument you are looking for.

exit_key() → None: Get back the normal screen after an error: send an EXIT key press event

classmethod find_instrument(name: str, instrument_class: type[T] | None = None) → T | Instrument

Find an existing instrument by name.

Parameters:

name – Name of the instrument.
instrument_class – The type of instrument you are looking for.

Returns:

The instrument found.

Raises:

KeyError – If no instrument of that name was found, or if its reference is invalid (dead).
TypeError – If a specific class was requested but a different type was found.

property full_name: str

Full name of the instrument.

For an InstrumentModule this includes all parents separated by _

get(param_name: str) → Any

Shortcut for getting a parameter from its name.

Parameters:: param_name – The name of a parameter of this instrument.
Returns:: The current value of the parameter.

get_component(full_name: str) → MetadatableWithName

Recursively get a component of the instrument by full_name.

Parameters:: full_name – The name of the component to get.
Returns:: The component with the given name.
Raises:: KeyError – If the component does not exist.

get_idn() → dict[str, str | None]

Parse a standard VISA *IDN? response into an ID dict.

Even though this is the VISA standard, it applies to various other types as well, such as IPInstruments, so it is included here in the Instrument base class.

Override this if your instrument does not support *IDN? or returns a nonstandard IDN string. This string is supposed to be a comma-separated list of vendor, model, serial, and firmware, but semicolon and colon are also common separators so we accept them here as well.

Returns:: A dict containing vendor, model, serial, and firmware.

classmethod instances() → list[T]

Get all currently defined instances of this instrument class.

You can use this to get the objects back if you lose track of them, and it’s also used by the test system to find objects to test against.

Returns:: A list of instances.

invalidate_cache() → None

Invalidate the cache of all parameters on the instrument. Calling this method will recursively mark the cache of all parameters on the instrument and any parameter on instrument modules as invalid.

This is useful if you have performed manual operations (e.g. using the frontpanel) which changes the state of the instrument outside QCoDeS.

This in turn means that the next snapshot of the instrument will trigger a (potentially slow) reread of all parameters of the instrument if you pass update=None to snapshot.

static is_valid(instr_instance: Instrument) → bool

Check if a given instance of an instrument is valid: if an instrument has been closed, its instance is not longer a “valid” instrument.

Parameters:: instr_instance – Instance of an Instrument class or its subclass.

property label: str: Nicely formatted label of the instrument.

load_metadata(metadata: Mapping[str, Any]) → None

Load metadata into this classes metadata dictionary.

Parameters:: metadata – Metadata to load.

property name: str

Full name of the instrument

This is equivalent to full_name() for backwards compatibility.

property name_parts: list[str]: A list of all the parts of the instrument name from root_instrument() to the current InstrumentModule.

omit_delegate_attrs: ClassVar[list[str]] = []: A list of attribute names (strings) to not delegate to any other dictionary or object.

property parent: InstrumentBase | None: The parent instrument. By default, this is None. Any SubInstrument should subclass this to return the parent instrument.

print_readable_snapshot(update: bool = False, max_chars: int = 80) → None

Prints a readable version of the snapshot. The readable snapshot includes the name, value and unit of each parameter. A convenience function to quickly get an overview of the status of an instrument.

Parameters:

update – If True, update the state by querying the instrument. If False, just use the latest values in memory. This argument gets passed to the snapshot function.
max_chars – the maximum number of characters per line. The readable snapshot will be cropped if this value is exceeded. Defaults to 80 to be consistent with default terminal width.

classmethod record_instance(instance: Instrument) → None

Record (a weak ref to) an instance in a class’s instance list.

Also records the instance in list of all instruments, and verifies that there are no other instruments with the same name.

This method is called after initialization of the instrument is completed.

Parameters:: instance – Instance to record.
Raises:: KeyError – If another instance with the same name is already present.

classmethod remove_instance(instance: Instrument) → None

Remove a particular instance from the record.

Parameters:: instance – The instance to remove

reset() → None: Reset instrument to factory defaults. This resets both channels.

property root_instrument: InstrumentBase

The topmost parent of this module.

For the root_instrument this is self.

set(param_name: str, value: Any) → None

Shortcut for setting a parameter from its name and new value.

Parameters:

param_name – The name of a parameter of this instrument.
value – The new value to set.

set_address(address: str) → None

Set the address for this instrument.

Parameters:: address – The visa resource name to use to connect. The address should be the actual address and just that. If you wish to change the backend for VISA, use the self.visalib attribute (and then call this function).

set_terminator(terminator: str | None) → None

Change the read terminator to use.

Parameters:: terminator – Character(s) to look for at the end of a read and to end each write command with. eg. \r\n. If None the terminator will not be set.

property short_name: str

Short name of the instrument.

For an InstrumentModule this does not include any parent names.

snapshot(update: bool | None = False) → dict[str, Any]

Decorate a snapshot dictionary with metadata. DO NOT override this method if you want metadata in the snapshot instead, override snapshot_base().

Parameters:: update – Passed to snapshot_base.
Returns:: Base snapshot.

snapshot_base(update: bool | None = True, params_to_skip_update: Sequence[str] | None = None) → dict[Any, Any]

State of the instrument as a JSON-compatible dict (everything that the custom JSON encoder class NumpyJSONEncoder supports).

Parameters:

update – If True, update the state by querying the instrument. If None only update if the state is known to be invalid. If False, just use the latest values in memory and never update.
params_to_skip_update – List of parameter names that will be skipped in update even if update is True. This is useful if you have parameters that are slow to update but can be updated in a different way (as in the qdac). If you want to skip the update of certain parameters in all snapshots, use the snapshot_get attribute of those parameters instead.

Returns:

base snapshot

Return type:

dict

validate_status(verbose: bool = False) → None

Validate the values of all gettable parameters

The validation is done for all parameters that have both a get and set method.

Parameters:: verbose – If True, then information about the parameters that are being check is printed.

write(cmd: str) → None

Write a command string with NO response to the hardware.

Subclasses that transform cmd should override this method, and in it call super().write(new_cmd). Subclasses that define a new hardware communication should instead override write_raw.

Parameters:: cmd – The string to send to the instrument.
Raises:: Exception – Wraps any underlying exception with extra context, including the command and the instrument.

write_raw(cmd: str) → None

Low-level interface to visa_handle.write.

Parameters:: cmd – The command to send to the instrument.

channels: list[Keithley2600Channel] = []

visabackend: str = visabackend

visa_handle: pyvisa.resources.MessageBasedResource = visa_handle: The VISA resource used by this instrument.

visalib: str | None = visalib

parameters: dict[str, ParameterBase] = {}: All the parameters supported by this instrument. Usually populated via add_parameter().

functions: dict[str, Function] = {}: All the functions supported by this instrument. Usually populated via add_function().

submodules: dict[str, InstrumentModule | ChannelTuple] = {}: All the submodules of this instrument such as channel lists or logical groupings of parameters. Usually populated via add_submodule().

instrument_modules: dict[str, InstrumentModule] = {}: All the InstrumentModule of this instrument Usually populated via add_submodule().

log: InstrumentLoggerAdapter = get_instrument_logger(self, __name__)

metadata: dict[str, Any] = {}

resource_manager = resource_manager: The VISA resource manager used by this instrument.

class qcodes.instrument_drivers.Keithley.Keithley2612B(name: str, address: str, **kwargs: Any)[source]

Bases: Keithley2600

QCoDeS driver for the Keithley 2612B Source-Meter

Parameters:

name – Name to use internally in QCoDeS
address – VISA resource address
**kwargs – kwargs are forwarded to base class.

Methods:

`__del__`()	Close the instrument and remove its instance record.
`__getitem__`(key)	Delegate instrument['name'] to parameter or function 'name'.
`__getstate__`()	Prevent pickling instruments, and give a nice error message.
`__repr__`()	Simplified repr giving just the class and name.
`add_function`(name, **kwargs)	Bind one `Function` to this instrument.
`add_parameter`(name[, parameter_class])	Bind one Parameter to this instrument.
`add_submodule`(name, submodule)	Bind one submodule to this instrument.
`ask`(cmd)	Override of normal ask.
`ask_raw`(cmd)	Low-level interface to `visa_handle.ask`.
`call`(func_name, *args)	Shortcut for calling a function from its name.
`close`()	Disconnect and irreversibly tear down the instrument.
`close_all`()	Try to close all instruments registered in `_all_instruments` This is handy for use with atexit to ensure that all instruments are closed when a python session is closed.
`connect_message`([idn_param, begin_time])	Print a standard message on initial connection to an instrument.
`device_clear`()	Clear the buffers of the device
`display_clear`()	This function clears the display, but also leaves it in user mode
`display_normal`()	Set the display to the default mode
`exist`(name[, instrument_class])	Check if an instrument with a given names exists (i.e. is already instantiated).
`exit_key`()	Get back the normal screen after an error: send an EXIT key press event
`find_instrument`(name[, instrument_class])	Find an existing instrument by name.
`get`(param_name)	Shortcut for getting a parameter from its name.
`get_component`(full_name)	Recursively get a component of the instrument by full_name.
`get_idn`()	Parse a standard VISA `*IDN?` response into an ID dict.
`instances`()	Get all currently defined instances of this instrument class.
`invalidate_cache`()	Invalidate the cache of all parameters on the instrument.
`is_valid`(instr_instance)	Check if a given instance of an instrument is valid: if an instrument has been closed, its instance is not longer a "valid" instrument.
`load_metadata`(metadata)	Load metadata into this classes metadata dictionary.
`print_readable_snapshot`([update, max_chars])	Prints a readable version of the snapshot.
`record_instance`(instance)	Record (a weak ref to) an instance in a class's instance list.
`remove_instance`(instance)	Remove a particular instance from the record.
`reset`()	Reset instrument to factory defaults.
`set`(param_name, value)	Shortcut for setting a parameter from its name and new value.
`set_address`(address)	Set the address for this instrument.
`set_terminator`(terminator)	Change the read terminator to use.
`snapshot`([update])	Decorate a snapshot dictionary with metadata.
`snapshot_base`([update, params_to_skip_update])	State of the instrument as a JSON-compatible dict (everything that the custom JSON encoder class `NumpyJSONEncoder` supports).
`validate_status`([verbose])	Validate the values of all gettable parameters
`write`(cmd)	Write a command string with NO response to the hardware.
`write_raw`(cmd)	Low-level interface to `visa_handle.write`.

Attributes:

`ancestors`	Ancestors in the form of a list of `InstrumentBase`
`delegate_attr_dicts`	A list of names (strings) of dictionaries which are (or will be) attributes of `self`, whose keys should be treated as attributes of `self`.
`delegate_attr_objects`	A list of names (strings) of objects which are (or will be) attributes of `self`, whose attributes should be passed through to `self`.
`full_name`	Full name of the instrument.
`label`	Nicely formatted label of the instrument.
`name`	Full name of the instrument
`name_parts`	A list of all the parts of the instrument name from `root_instrument()` to the current `InstrumentModule`.
`omit_delegate_attrs`	A list of attribute names (strings) to not delegate to any other dictionary or object.
`parent`	The parent instrument.
`root_instrument`	The topmost parent of this module.
`short_name`	Short name of the instrument.
`visa_handle`	The VISA resource used by this instrument.
`resource_manager`	The VISA resource manager used by this instrument.
`parameters`	All the parameters supported by this instrument.
`functions`	All the functions supported by this instrument.
`submodules`	All the submodules of this instrument such as channel lists or logical groupings of parameters.
`instrument_modules`	All the `InstrumentModule` of this instrument Usually populated via `add_submodule()`.

__del__() → None: Close the instrument and remove its instance record.

__getitem__(key: str) → Callable[..., Any] | Parameter: Delegate instrument[‘name’] to parameter or function ‘name’.

__getstate__() → None: Prevent pickling instruments, and give a nice error message.

__repr__() → str: Simplified repr giving just the class and name.

add_function(name: str, **kwargs: Any) → None

Bind one Function to this instrument.

Instrument subclasses can call this repeatedly in their __init__ for every real function of the instrument.

This functionality is meant for simple cases, principally things that map to simple commands like *RST (reset) or those with just a few arguments. It requires a fixed argument count, and positional args only.

Note

We do not recommend the usage of Function for any new driver. Function does not add any significant features over a method defined on the class.

Parameters:

name – How the Function will be stored within instrument.Functions and also how you address it using the shortcut methods: instrument.call(func_name, *args) etc.
**kwargs – constructor kwargs for Function

Raises:

KeyError – If this instrument already has a function with this name.

add_parameter(name: str, parameter_class: type[ParameterBase] | None = None, **kwargs: Any) → None

Bind one Parameter to this instrument.

Instrument subclasses can call this repeatedly in their __init__ for every real parameter of the instrument.

In this sense, parameters are the state variables of the instrument, anything the user can set and/or get.

Parameters:

name – How the parameter will be stored within parameters and also how you address it using the shortcut methods: instrument.set(param_name, value) etc.
parameter_class – You can construct the parameter out of any class. Default parameters.Parameter.
**kwargs – Constructor arguments for parameter_class.

Raises:

KeyError – If this instrument already has a parameter with this name and the parameter being replaced is not an abstract parameter.
ValueError – If there is an existing abstract parameter and the unit of the new parameter is inconsistent with the existing one.

add_submodule(name: str, submodule: InstrumentModule | ChannelTuple) → None

Bind one submodule to this instrument.

Instrument subclasses can call this repeatedly in their __init__ method for every submodule of the instrument.

Submodules can effectively be considered as instruments within the main instrument, and should at minimum be snapshottable. For example, they can be used to either store logical groupings of parameters, which may or may not be repeated, or channel lists. They should either be an instance of an InstrumentModule or a ChannelTuple.

Parameters:

name – How the submodule will be stored within instrument.submodules and also how it can be addressed.
submodule – The submodule to be stored.

Raises:

KeyError – If this instrument already contains a submodule with this name.
TypeError – If the submodule that we are trying to add is not an instance of an Metadatable object.

property ancestors: tuple[InstrumentBase, ...]

Ancestors in the form of a list of InstrumentBase

The list starts with the current module then the parent and the parents parent until the root instrument is reached.

ask(cmd: str) → str: Override of normal ask. This is important, since queries to the instrument must be wrapped in ‘print()’

ask_raw(cmd: str) → str

Low-level interface to visa_handle.ask.

Parameters:: cmd – The command to send to the instrument.
Returns:: The instrument’s response.
Return type:: str

call(func_name: str, *args: Any) → Any

Shortcut for calling a function from its name.

Parameters:

func_name – The name of a function of this instrument.
*args – any arguments to the function.

Returns:

The return value of the function.

close() → None: Disconnect and irreversibly tear down the instrument.

classmethod close_all() → None

Try to close all instruments registered in _all_instruments This is handy for use with atexit to ensure that all instruments are closed when a python session is closed.

Examples

>>> atexit.register(qc.Instrument.close_all())

connect_message(idn_param: str = 'IDN', begin_time: float | None = None) → None

Print a standard message on initial connection to an instrument.

Parameters:

idn_param – Name of parameter that returns ID dict. Default IDN.
begin_time – time.time() when init started. Default is self._t0, set at start of Instrument.__init__.

delegate_attr_dicts: ClassVar[list[str]] = ['parameters', 'functions', 'submodules']: A list of names (strings) of dictionaries which are (or will be) attributes of self, whose keys should be treated as attributes of self.

delegate_attr_objects: ClassVar[list[str]] = []: A list of names (strings) of objects which are (or will be) attributes of self, whose attributes should be passed through to self.

device_clear() → None: Clear the buffers of the device

display_clear() → None: This function clears the display, but also leaves it in user mode

display_normal() → None: Set the display to the default mode

static exist(name: str, instrument_class: type[Instrument] | None = None) → bool

Check if an instrument with a given names exists (i.e. is already instantiated).

Parameters:

name – Name of the instrument.
instrument_class – The type of instrument you are looking for.

exit_key() → None: Get back the normal screen after an error: send an EXIT key press event

classmethod find_instrument(name: str, instrument_class: type[T] | None = None) → T | Instrument

Find an existing instrument by name.

Parameters:

name – Name of the instrument.
instrument_class – The type of instrument you are looking for.

Returns:

The instrument found.

Raises:

KeyError – If no instrument of that name was found, or if its reference is invalid (dead).
TypeError – If a specific class was requested but a different type was found.

property full_name: str

Full name of the instrument.

For an InstrumentModule this includes all parents separated by _

get(param_name: str) → Any

Shortcut for getting a parameter from its name.

Parameters:: param_name – The name of a parameter of this instrument.
Returns:: The current value of the parameter.

get_component(full_name: str) → MetadatableWithName

Recursively get a component of the instrument by full_name.

Parameters:: full_name – The name of the component to get.
Returns:: The component with the given name.
Raises:: KeyError – If the component does not exist.

get_idn() → dict[str, str | None]

Parse a standard VISA *IDN? response into an ID dict.

Even though this is the VISA standard, it applies to various other types as well, such as IPInstruments, so it is included here in the Instrument base class.

Override this if your instrument does not support *IDN? or returns a nonstandard IDN string. This string is supposed to be a comma-separated list of vendor, model, serial, and firmware, but semicolon and colon are also common separators so we accept them here as well.

Returns:: A dict containing vendor, model, serial, and firmware.

classmethod instances() → list[T]

Get all currently defined instances of this instrument class.

You can use this to get the objects back if you lose track of them, and it’s also used by the test system to find objects to test against.

Returns:: A list of instances.

invalidate_cache() → None

Invalidate the cache of all parameters on the instrument. Calling this method will recursively mark the cache of all parameters on the instrument and any parameter on instrument modules as invalid.

This is useful if you have performed manual operations (e.g. using the frontpanel) which changes the state of the instrument outside QCoDeS.

This in turn means that the next snapshot of the instrument will trigger a (potentially slow) reread of all parameters of the instrument if you pass update=None to snapshot.

static is_valid(instr_instance: Instrument) → bool

Check if a given instance of an instrument is valid: if an instrument has been closed, its instance is not longer a “valid” instrument.

Parameters:: instr_instance – Instance of an Instrument class or its subclass.

property label: str: Nicely formatted label of the instrument.

load_metadata(metadata: Mapping[str, Any]) → None

Load metadata into this classes metadata dictionary.

Parameters:: metadata – Metadata to load.

property name: str

Full name of the instrument

This is equivalent to full_name() for backwards compatibility.

property name_parts: list[str]: A list of all the parts of the instrument name from root_instrument() to the current InstrumentModule.

omit_delegate_attrs: ClassVar[list[str]] = []: A list of attribute names (strings) to not delegate to any other dictionary or object.

property parent: InstrumentBase | None: The parent instrument. By default, this is None. Any SubInstrument should subclass this to return the parent instrument.

print_readable_snapshot(update: bool = False, max_chars: int = 80) → None

Prints a readable version of the snapshot. The readable snapshot includes the name, value and unit of each parameter. A convenience function to quickly get an overview of the status of an instrument.

Parameters:

update – If True, update the state by querying the instrument. If False, just use the latest values in memory. This argument gets passed to the snapshot function.
max_chars – the maximum number of characters per line. The readable snapshot will be cropped if this value is exceeded. Defaults to 80 to be consistent with default terminal width.

classmethod record_instance(instance: Instrument) → None

Record (a weak ref to) an instance in a class’s instance list.

Also records the instance in list of all instruments, and verifies that there are no other instruments with the same name.

This method is called after initialization of the instrument is completed.

Parameters:: instance – Instance to record.
Raises:: KeyError – If another instance with the same name is already present.

classmethod remove_instance(instance: Instrument) → None

Remove a particular instance from the record.

Parameters:: instance – The instance to remove

reset() → None: Reset instrument to factory defaults. This resets both channels.

property root_instrument: InstrumentBase

The topmost parent of this module.

For the root_instrument this is self.

set(param_name: str, value: Any) → None

Shortcut for setting a parameter from its name and new value.

Parameters:

param_name – The name of a parameter of this instrument.
value – The new value to set.

set_address(address: str) → None

Set the address for this instrument.

Parameters:: address – The visa resource name to use to connect. The address should be the actual address and just that. If you wish to change the backend for VISA, use the self.visalib attribute (and then call this function).

set_terminator(terminator: str | None) → None

Change the read terminator to use.

Parameters:: terminator – Character(s) to look for at the end of a read and to end each write command with. eg. \r\n. If None the terminator will not be set.

property short_name: str

Short name of the instrument.

For an InstrumentModule this does not include any parent names.

snapshot(update: bool | None = False) → dict[str, Any]

Decorate a snapshot dictionary with metadata. DO NOT override this method if you want metadata in the snapshot instead, override snapshot_base().

Parameters:: update – Passed to snapshot_base.
Returns:: Base snapshot.

snapshot_base(update: bool | None = True, params_to_skip_update: Sequence[str] | None = None) → dict[Any, Any]

State of the instrument as a JSON-compatible dict (everything that the custom JSON encoder class NumpyJSONEncoder supports).

Parameters:

update – If True, update the state by querying the instrument. If None only update if the state is known to be invalid. If False, just use the latest values in memory and never update.
params_to_skip_update – List of parameter names that will be skipped in update even if update is True. This is useful if you have parameters that are slow to update but can be updated in a different way (as in the qdac). If you want to skip the update of certain parameters in all snapshots, use the snapshot_get attribute of those parameters instead.

Returns:

base snapshot

Return type:

dict

validate_status(verbose: bool = False) → None

Validate the values of all gettable parameters

The validation is done for all parameters that have both a get and set method.

Parameters:: verbose – If True, then information about the parameters that are being check is printed.

write(cmd: str) → None

Write a command string with NO response to the hardware.

Subclasses that transform cmd should override this method, and in it call super().write(new_cmd). Subclasses that define a new hardware communication should instead override write_raw.

Parameters:: cmd – The string to send to the instrument.
Raises:: Exception – Wraps any underlying exception with extra context, including the command and the instrument.

write_raw(cmd: str) → None

Low-level interface to visa_handle.write.

Parameters:: cmd – The command to send to the instrument.

channels: list[Keithley2600Channel] = []

visabackend: str = visabackend

visa_handle: pyvisa.resources.MessageBasedResource = visa_handle: The VISA resource used by this instrument.

visalib: str | None = visalib

parameters: dict[str, ParameterBase] = {}: All the parameters supported by this instrument. Usually populated via add_parameter().

functions: dict[str, Function] = {}: All the functions supported by this instrument. Usually populated via add_function().

submodules: dict[str, InstrumentModule | ChannelTuple] = {}: All the submodules of this instrument such as channel lists or logical groupings of parameters. Usually populated via add_submodule().

instrument_modules: dict[str, InstrumentModule] = {}: All the InstrumentModule of this instrument Usually populated via add_submodule().

log: InstrumentLoggerAdapter = get_instrument_logger(self, __name__)

metadata: dict[str, Any] = {}

resource_manager = resource_manager: The VISA resource manager used by this instrument.

class qcodes.instrument_drivers.Keithley.Keithley2614B(name: str, address: str, **kwargs: Any)[source]

Bases: Keithley2600

QCoDeS driver for the Keithley 2614B Source-Meter

Parameters:

name – Name to use internally in QCoDeS
address – VISA resource address
**kwargs – kwargs are forwarded to base class.

Methods:

`__del__`()	Close the instrument and remove its instance record.
`__getitem__`(key)	Delegate instrument['name'] to parameter or function 'name'.
`__getstate__`()	Prevent pickling instruments, and give a nice error message.
`__repr__`()	Simplified repr giving just the class and name.
`add_function`(name, **kwargs)	Bind one `Function` to this instrument.
`add_parameter`(name[, parameter_class])	Bind one Parameter to this instrument.
`add_submodule`(name, submodule)	Bind one submodule to this instrument.
`ask`(cmd)	Override of normal ask.
`ask_raw`(cmd)	Low-level interface to `visa_handle.ask`.
`call`(func_name, *args)	Shortcut for calling a function from its name.
`close`()	Disconnect and irreversibly tear down the instrument.
`close_all`()	Try to close all instruments registered in `_all_instruments` This is handy for use with atexit to ensure that all instruments are closed when a python session is closed.
`connect_message`([idn_param, begin_time])	Print a standard message on initial connection to an instrument.
`device_clear`()	Clear the buffers of the device
`display_clear`()	This function clears the display, but also leaves it in user mode
`display_normal`()	Set the display to the default mode
`exist`(name[, instrument_class])	Check if an instrument with a given names exists (i.e. is already instantiated).
`exit_key`()	Get back the normal screen after an error: send an EXIT key press event
`find_instrument`(name[, instrument_class])	Find an existing instrument by name.
`get`(param_name)	Shortcut for getting a parameter from its name.
`get_component`(full_name)	Recursively get a component of the instrument by full_name.
`get_idn`()	Parse a standard VISA `*IDN?` response into an ID dict.
`instances`()	Get all currently defined instances of this instrument class.
`invalidate_cache`()	Invalidate the cache of all parameters on the instrument.
`is_valid`(instr_instance)	Check if a given instance of an instrument is valid: if an instrument has been closed, its instance is not longer a "valid" instrument.
`load_metadata`(metadata)	Load metadata into this classes metadata dictionary.
`print_readable_snapshot`([update, max_chars])	Prints a readable version of the snapshot.
`record_instance`(instance)	Record (a weak ref to) an instance in a class's instance list.
`remove_instance`(instance)	Remove a particular instance from the record.
`reset`()	Reset instrument to factory defaults.
`set`(param_name, value)	Shortcut for setting a parameter from its name and new value.
`set_address`(address)	Set the address for this instrument.
`set_terminator`(terminator)	Change the read terminator to use.
`snapshot`([update])	Decorate a snapshot dictionary with metadata.
`snapshot_base`([update, params_to_skip_update])	State of the instrument as a JSON-compatible dict (everything that the custom JSON encoder class `NumpyJSONEncoder` supports).
`validate_status`([verbose])	Validate the values of all gettable parameters
`write`(cmd)	Write a command string with NO response to the hardware.
`write_raw`(cmd)	Low-level interface to `visa_handle.write`.

Attributes:

`ancestors`	Ancestors in the form of a list of `InstrumentBase`
`delegate_attr_dicts`	A list of names (strings) of dictionaries which are (or will be) attributes of `self`, whose keys should be treated as attributes of `self`.
`delegate_attr_objects`	A list of names (strings) of objects which are (or will be) attributes of `self`, whose attributes should be passed through to `self`.
`full_name`	Full name of the instrument.
`label`	Nicely formatted label of the instrument.
`name`	Full name of the instrument
`name_parts`	A list of all the parts of the instrument name from `root_instrument()` to the current `InstrumentModule`.
`omit_delegate_attrs`	A list of attribute names (strings) to not delegate to any other dictionary or object.
`parent`	The parent instrument.
`root_instrument`	The topmost parent of this module.
`short_name`	Short name of the instrument.
`visa_handle`	The VISA resource used by this instrument.
`resource_manager`	The VISA resource manager used by this instrument.
`parameters`	All the parameters supported by this instrument.
`functions`	All the functions supported by this instrument.
`submodules`	All the submodules of this instrument such as channel lists or logical groupings of parameters.
`instrument_modules`	All the `InstrumentModule` of this instrument Usually populated via `add_submodule()`.

__del__() → None: Close the instrument and remove its instance record.

__getitem__(key: str) → Callable[..., Any] | Parameter: Delegate instrument[‘name’] to parameter or function ‘name’.

__getstate__() → None: Prevent pickling instruments, and give a nice error message.

__repr__() → str: Simplified repr giving just the class and name.

add_function(name: str, **kwargs: Any) → None

Bind one Function to this instrument.

Instrument subclasses can call this repeatedly in their __init__ for every real function of the instrument.

This functionality is meant for simple cases, principally things that map to simple commands like *RST (reset) or those with just a few arguments. It requires a fixed argument count, and positional args only.

Note

We do not recommend the usage of Function for any new driver. Function does not add any significant features over a method defined on the class.

Parameters:

name – How the Function will be stored within instrument.Functions and also how you address it using the shortcut methods: instrument.call(func_name, *args) etc.
**kwargs – constructor kwargs for Function

Raises:

KeyError – If this instrument already has a function with this name.

add_parameter(name: str, parameter_class: type[ParameterBase] | None = None, **kwargs: Any) → None

Bind one Parameter to this instrument.

Instrument subclasses can call this repeatedly in their __init__ for every real parameter of the instrument.

In this sense, parameters are the state variables of the instrument, anything the user can set and/or get.

Parameters:

name – How the parameter will be stored within parameters and also how you address it using the shortcut methods: instrument.set(param_name, value) etc.
parameter_class – You can construct the parameter out of any class. Default parameters.Parameter.
**kwargs – Constructor arguments for parameter_class.

Raises:

KeyError – If this instrument already has a parameter with this name and the parameter being replaced is not an abstract parameter.
ValueError – If there is an existing abstract parameter and the unit of the new parameter is inconsistent with the existing one.

add_submodule(name: str, submodule: InstrumentModule | ChannelTuple) → None

Bind one submodule to this instrument.

Instrument subclasses can call this repeatedly in their __init__ method for every submodule of the instrument.

Submodules can effectively be considered as instruments within the main instrument, and should at minimum be snapshottable. For example, they can be used to either store logical groupings of parameters, which may or may not be repeated, or channel lists. They should either be an instance of an InstrumentModule or a ChannelTuple.

Parameters:

name – How the submodule will be stored within instrument.submodules and also how it can be addressed.
submodule – The submodule to be stored.

Raises:

KeyError – If this instrument already contains a submodule with this name.
TypeError – If the submodule that we are trying to add is not an instance of an Metadatable object.

property ancestors: tuple[InstrumentBase, ...]

Ancestors in the form of a list of InstrumentBase

The list starts with the current module then the parent and the parents parent until the root instrument is reached.

ask(cmd: str) → str: Override of normal ask. This is important, since queries to the instrument must be wrapped in ‘print()’

ask_raw(cmd: str) → str

Low-level interface to visa_handle.ask.

Parameters:: cmd – The command to send to the instrument.
Returns:: The instrument’s response.
Return type:: str

call(func_name: str, *args: Any) → Any

Shortcut for calling a function from its name.

Parameters:

func_name – The name of a function of this instrument.
*args – any arguments to the function.

Returns:

The return value of the function.

close() → None: Disconnect and irreversibly tear down the instrument.

classmethod close_all() → None

Try to close all instruments registered in _all_instruments This is handy for use with atexit to ensure that all instruments are closed when a python session is closed.

Examples

>>> atexit.register(qc.Instrument.close_all())

connect_message(idn_param: str = 'IDN', begin_time: float | None = None) → None

Print a standard message on initial connection to an instrument.

Parameters:

idn_param – Name of parameter that returns ID dict. Default IDN.
begin_time – time.time() when init started. Default is self._t0, set at start of Instrument.__init__.

delegate_attr_dicts: ClassVar[list[str]] = ['parameters', 'functions', 'submodules']: A list of names (strings) of dictionaries which are (or will be) attributes of self, whose keys should be treated as attributes of self.

delegate_attr_objects: ClassVar[list[str]] = []: A list of names (strings) of objects which are (or will be) attributes of self, whose attributes should be passed through to self.

device_clear() → None: Clear the buffers of the device

display_clear() → None: This function clears the display, but also leaves it in user mode

display_normal() → None: Set the display to the default mode

static exist(name: str, instrument_class: type[Instrument] | None = None) → bool

Check if an instrument with a given names exists (i.e. is already instantiated).

Parameters:

name – Name of the instrument.
instrument_class – The type of instrument you are looking for.

exit_key() → None: Get back the normal screen after an error: send an EXIT key press event

classmethod find_instrument(name: str, instrument_class: type[T] | None = None) → T | Instrument

Find an existing instrument by name.

Parameters:

name – Name of the instrument.
instrument_class – The type of instrument you are looking for.

Returns:

The instrument found.

Raises:

KeyError – If no instrument of that name was found, or if its reference is invalid (dead).
TypeError – If a specific class was requested but a different type was found.

property full_name: str

Full name of the instrument.

For an InstrumentModule this includes all parents separated by _

get(param_name: str) → Any

Shortcut for getting a parameter from its name.

Parameters:: param_name – The name of a parameter of this instrument.
Returns:: The current value of the parameter.

get_component(full_name: str) → MetadatableWithName

Recursively get a component of the instrument by full_name.

Parameters:: full_name – The name of the component to get.
Returns:: The component with the given name.
Raises:: KeyError – If the component does not exist.

get_idn() → dict[str, str | None]

Parse a standard VISA *IDN? response into an ID dict.

Even though this is the VISA standard, it applies to various other types as well, such as IPInstruments, so it is included here in the Instrument base class.

Override this if your instrument does not support *IDN? or returns a nonstandard IDN string. This string is supposed to be a comma-separated list of vendor, model, serial, and firmware, but semicolon and colon are also common separators so we accept them here as well.

Returns:: A dict containing vendor, model, serial, and firmware.

classmethod instances() → list[T]

Get all currently defined instances of this instrument class.

You can use this to get the objects back if you lose track of them, and it’s also used by the test system to find objects to test against.

Returns:: A list of instances.

invalidate_cache() → None

Invalidate the cache of all parameters on the instrument. Calling this method will recursively mark the cache of all parameters on the instrument and any parameter on instrument modules as invalid.

This is useful if you have performed manual operations (e.g. using the frontpanel) which changes the state of the instrument outside QCoDeS.

This in turn means that the next snapshot of the instrument will trigger a (potentially slow) reread of all parameters of the instrument if you pass update=None to snapshot.

static is_valid(instr_instance: Instrument) → bool

Check if a given instance of an instrument is valid: if an instrument has been closed, its instance is not longer a “valid” instrument.

Parameters:: instr_instance – Instance of an Instrument class or its subclass.

property label: str: Nicely formatted label of the instrument.

load_metadata(metadata: Mapping[str, Any]) → None

Load metadata into this classes metadata dictionary.

Parameters:: metadata – Metadata to load.

property name: str

Full name of the instrument

This is equivalent to full_name() for backwards compatibility.

property name_parts: list[str]: A list of all the parts of the instrument name from root_instrument() to the current InstrumentModule.

omit_delegate_attrs: ClassVar[list[str]] = []: A list of attribute names (strings) to not delegate to any other dictionary or object.

property parent: InstrumentBase | None: The parent instrument. By default, this is None. Any SubInstrument should subclass this to return the parent instrument.

print_readable_snapshot(update: bool = False, max_chars: int = 80) → None

Prints a readable version of the snapshot. The readable snapshot includes the name, value and unit of each parameter. A convenience function to quickly get an overview of the status of an instrument.

Parameters:

update – If True, update the state by querying the instrument. If False, just use the latest values in memory. This argument gets passed to the snapshot function.
max_chars – the maximum number of characters per line. The readable snapshot will be cropped if this value is exceeded. Defaults to 80 to be consistent with default terminal width.

classmethod record_instance(instance: Instrument) → None

Record (a weak ref to) an instance in a class’s instance list.

Also records the instance in list of all instruments, and verifies that there are no other instruments with the same name.

This method is called after initialization of the instrument is completed.

Parameters:: instance – Instance to record.
Raises:: KeyError – If another instance with the same name is already present.

classmethod remove_instance(instance: Instrument) → None

Remove a particular instance from the record.

Parameters:: instance – The instance to remove

reset() → None: Reset instrument to factory defaults. This resets both channels.

property root_instrument: InstrumentBase

The topmost parent of this module.

For the root_instrument this is self.

set(param_name: str, value: Any) → None

Shortcut for setting a parameter from its name and new value.

Parameters:

param_name – The name of a parameter of this instrument.
value – The new value to set.

set_address(address: str) → None

Set the address for this instrument.

Parameters:: address – The visa resource name to use to connect. The address should be the actual address and just that. If you wish to change the backend for VISA, use the self.visalib attribute (and then call this function).

set_terminator(terminator: str | None) → None

Change the read terminator to use.

Parameters:: terminator – Character(s) to look for at the end of a read and to end each write command with. eg. \r\n. If None the terminator will not be set.

property short_name: str

Short name of the instrument.

For an InstrumentModule this does not include any parent names.

snapshot(update: bool | None = False) → dict[str, Any]

Decorate a snapshot dictionary with metadata. DO NOT override this method if you want metadata in the snapshot instead, override snapshot_base().

Parameters:: update – Passed to snapshot_base.
Returns:: Base snapshot.

snapshot_base(update: bool | None = True, params_to_skip_update: Sequence[str] | None = None) → dict[Any, Any]

State of the instrument as a JSON-compatible dict (everything that the custom JSON encoder class NumpyJSONEncoder supports).

Parameters:

update – If True, update the state by querying the instrument. If None only update if the state is known to be invalid. If False, just use the latest values in memory and never update.
params_to_skip_update – List of parameter names that will be skipped in update even if update is True. This is useful if you have parameters that are slow to update but can be updated in a different way (as in the qdac). If you want to skip the update of certain parameters in all snapshots, use the snapshot_get attribute of those parameters instead.

Returns:

base snapshot

Return type:

dict

validate_status(verbose: bool = False) → None

Validate the values of all gettable parameters

The validation is done for all parameters that have both a get and set method.

Parameters:: verbose – If True, then information about the parameters that are being check is printed.

write(cmd: str) → None

Write a command string with NO response to the hardware.

Subclasses that transform cmd should override this method, and in it call super().write(new_cmd). Subclasses that define a new hardware communication should instead override write_raw.

Parameters:: cmd – The string to send to the instrument.
Raises:: Exception – Wraps any underlying exception with extra context, including the command and the instrument.

write_raw(cmd: str) → None

Low-level interface to visa_handle.write.

Parameters:: cmd – The command to send to the instrument.

channels: list[Keithley2600Channel] = []

visabackend: str = visabackend

visa_handle: pyvisa.resources.MessageBasedResource = visa_handle: The VISA resource used by this instrument.

visalib: str | None = visalib

parameters: dict[str, ParameterBase] = {}: All the parameters supported by this instrument. Usually populated via add_parameter().

functions: dict[str, Function] = {}: All the functions supported by this instrument. Usually populated via add_function().

submodules: dict[str, InstrumentModule | ChannelTuple] = {}: All the submodules of this instrument such as channel lists or logical groupings of parameters. Usually populated via add_submodule().

instrument_modules: dict[str, InstrumentModule] = {}: All the InstrumentModule of this instrument Usually populated via add_submodule().

log: InstrumentLoggerAdapter = get_instrument_logger(self, __name__)

metadata: dict[str, Any] = {}

resource_manager = resource_manager: The VISA resource manager used by this instrument.

class qcodes.instrument_drivers.Keithley.Keithley2634B(name: str, address: str, **kwargs: Any)[source]

Bases: Keithley2600

QCoDeS driver for the Keithley 2634B Source-Meter

Parameters:

name – Name to use internally in QCoDeS
address – VISA resource address
**kwargs – kwargs are forwarded to base class.

Methods:

`__del__`()	Close the instrument and remove its instance record.
`__getitem__`(key)	Delegate instrument['name'] to parameter or function 'name'.
`__getstate__`()	Prevent pickling instruments, and give a nice error message.
`__repr__`()	Simplified repr giving just the class and name.
`add_function`(name, **kwargs)	Bind one `Function` to this instrument.
`add_parameter`(name[, parameter_class])	Bind one Parameter to this instrument.
`add_submodule`(name, submodule)	Bind one submodule to this instrument.
`ask`(cmd)	Override of normal ask.
`ask_raw`(cmd)	Low-level interface to `visa_handle.ask`.
`call`(func_name, *args)	Shortcut for calling a function from its name.
`close`()	Disconnect and irreversibly tear down the instrument.
`close_all`()	Try to close all instruments registered in `_all_instruments` This is handy for use with atexit to ensure that all instruments are closed when a python session is closed.
`connect_message`([idn_param, begin_time])	Print a standard message on initial connection to an instrument.
`device_clear`()	Clear the buffers of the device
`display_clear`()	This function clears the display, but also leaves it in user mode
`display_normal`()	Set the display to the default mode
`exist`(name[, instrument_class])	Check if an instrument with a given names exists (i.e. is already instantiated).
`exit_key`()	Get back the normal screen after an error: send an EXIT key press event
`find_instrument`(name[, instrument_class])	Find an existing instrument by name.
`get`(param_name)	Shortcut for getting a parameter from its name.
`get_component`(full_name)	Recursively get a component of the instrument by full_name.
`get_idn`()	Parse a standard VISA `*IDN?` response into an ID dict.
`instances`()	Get all currently defined instances of this instrument class.
`invalidate_cache`()	Invalidate the cache of all parameters on the instrument.
`is_valid`(instr_instance)	Check if a given instance of an instrument is valid: if an instrument has been closed, its instance is not longer a "valid" instrument.
`load_metadata`(metadata)	Load metadata into this classes metadata dictionary.
`print_readable_snapshot`([update, max_chars])	Prints a readable version of the snapshot.
`record_instance`(instance)	Record (a weak ref to) an instance in a class's instance list.
`remove_instance`(instance)	Remove a particular instance from the record.
`reset`()	Reset instrument to factory defaults.
`set`(param_name, value)	Shortcut for setting a parameter from its name and new value.
`set_address`(address)	Set the address for this instrument.
`set_terminator`(terminator)	Change the read terminator to use.
`snapshot`([update])	Decorate a snapshot dictionary with metadata.
`snapshot_base`([update, params_to_skip_update])	State of the instrument as a JSON-compatible dict (everything that the custom JSON encoder class `NumpyJSONEncoder` supports).
`validate_status`([verbose])	Validate the values of all gettable parameters
`write`(cmd)	Write a command string with NO response to the hardware.
`write_raw`(cmd)	Low-level interface to `visa_handle.write`.

Attributes:

`ancestors`	Ancestors in the form of a list of `InstrumentBase`
`delegate_attr_dicts`	A list of names (strings) of dictionaries which are (or will be) attributes of `self`, whose keys should be treated as attributes of `self`.
`delegate_attr_objects`	A list of names (strings) of objects which are (or will be) attributes of `self`, whose attributes should be passed through to `self`.
`full_name`	Full name of the instrument.
`label`	Nicely formatted label of the instrument.
`name`	Full name of the instrument
`name_parts`	A list of all the parts of the instrument name from `root_instrument()` to the current `InstrumentModule`.
`omit_delegate_attrs`	A list of attribute names (strings) to not delegate to any other dictionary or object.
`parent`	The parent instrument.
`root_instrument`	The topmost parent of this module.
`short_name`	Short name of the instrument.
`visa_handle`	The VISA resource used by this instrument.
`resource_manager`	The VISA resource manager used by this instrument.
`parameters`	All the parameters supported by this instrument.
`functions`	All the functions supported by this instrument.
`submodules`	All the submodules of this instrument such as channel lists or logical groupings of parameters.
`instrument_modules`	All the `InstrumentModule` of this instrument Usually populated via `add_submodule()`.

__del__() → None: Close the instrument and remove its instance record.

__getitem__(key: str) → Callable[..., Any] | Parameter: Delegate instrument[‘name’] to parameter or function ‘name’.

__getstate__() → None: Prevent pickling instruments, and give a nice error message.

__repr__() → str: Simplified repr giving just the class and name.

add_function(name: str, **kwargs: Any) → None

Bind one Function to this instrument.

Instrument subclasses can call this repeatedly in their __init__ for every real function of the instrument.

This functionality is meant for simple cases, principally things that map to simple commands like *RST (reset) or those with just a few arguments. It requires a fixed argument count, and positional args only.

Note

We do not recommend the usage of Function for any new driver. Function does not add any significant features over a method defined on the class.

Parameters:

name – How the Function will be stored within instrument.Functions and also how you address it using the shortcut methods: instrument.call(func_name, *args) etc.
**kwargs – constructor kwargs for Function

Raises:

KeyError – If this instrument already has a function with this name.

add_parameter(name: str, parameter_class: type[ParameterBase] | None = None, **kwargs: Any) → None

Bind one Parameter to this instrument.

Instrument subclasses can call this repeatedly in their __init__ for every real parameter of the instrument.

In this sense, parameters are the state variables of the instrument, anything the user can set and/or get.

Parameters:

name – How the parameter will be stored within parameters and also how you address it using the shortcut methods: instrument.set(param_name, value) etc.
parameter_class – You can construct the parameter out of any class. Default parameters.Parameter.
**kwargs – Constructor arguments for parameter_class.

Raises:

KeyError – If this instrument already has a parameter with this name and the parameter being replaced is not an abstract parameter.
ValueError – If there is an existing abstract parameter and the unit of the new parameter is inconsistent with the existing one.

add_submodule(name: str, submodule: InstrumentModule | ChannelTuple) → None

Bind one submodule to this instrument.

Instrument subclasses can call this repeatedly in their __init__ method for every submodule of the instrument.

Submodules can effectively be considered as instruments within the main instrument, and should at minimum be snapshottable. For example, they can be used to either store logical groupings of parameters, which may or may not be repeated, or channel lists. They should either be an instance of an InstrumentModule or a ChannelTuple.

Parameters:

name – How the submodule will be stored within instrument.submodules and also how it can be addressed.
submodule – The submodule to be stored.

Raises:

KeyError – If this instrument already contains a submodule with this name.
TypeError – If the submodule that we are trying to add is not an instance of an Metadatable object.

property ancestors: tuple[InstrumentBase, ...]

Ancestors in the form of a list of InstrumentBase

The list starts with the current module then the parent and the parents parent until the root instrument is reached.

ask(cmd: str) → str: Override of normal ask. This is important, since queries to the instrument must be wrapped in ‘print()’

ask_raw(cmd: str) → str

Low-level interface to visa_handle.ask.

Parameters:: cmd – The command to send to the instrument.
Returns:: The instrument’s response.
Return type:: str

call(func_name: str, *args: Any) → Any

Shortcut for calling a function from its name.

Parameters:

func_name – The name of a function of this instrument.
*args – any arguments to the function.

Returns:

The return value of the function.

close() → None: Disconnect and irreversibly tear down the instrument.

classmethod close_all() → None

Try to close all instruments registered in _all_instruments This is handy for use with atexit to ensure that all instruments are closed when a python session is closed.

Examples

>>> atexit.register(qc.Instrument.close_all())

connect_message(idn_param: str = 'IDN', begin_time: float | None = None) → None

Print a standard message on initial connection to an instrument.

Parameters:

idn_param – Name of parameter that returns ID dict. Default IDN.
begin_time – time.time() when init started. Default is self._t0, set at start of Instrument.__init__.

delegate_attr_dicts: ClassVar[list[str]] = ['parameters', 'functions', 'submodules']: A list of names (strings) of dictionaries which are (or will be) attributes of self, whose keys should be treated as attributes of self.

delegate_attr_objects: ClassVar[list[str]] = []: A list of names (strings) of objects which are (or will be) attributes of self, whose attributes should be passed through to self.

device_clear() → None: Clear the buffers of the device

display_clear() → None: This function clears the display, but also leaves it in user mode

display_normal() → None: Set the display to the default mode

static exist(name: str, instrument_class: type[Instrument] | None = None) → bool

Check if an instrument with a given names exists (i.e. is already instantiated).

Parameters:

name – Name of the instrument.
instrument_class – The type of instrument you are looking for.

exit_key() → None: Get back the normal screen after an error: send an EXIT key press event

classmethod find_instrument(name: str, instrument_class: type[T] | None = None) → T | Instrument

Find an existing instrument by name.

Parameters:

name – Name of the instrument.
instrument_class – The type of instrument you are looking for.

Returns:

The instrument found.

Raises:

KeyError – If no instrument of that name was found, or if its reference is invalid (dead).
TypeError – If a specific class was requested but a different type was found.

property full_name: str

Full name of the instrument.

For an InstrumentModule this includes all parents separated by _

get(param_name: str) → Any

Shortcut for getting a parameter from its name.

Parameters:: param_name – The name of a parameter of this instrument.
Returns:: The current value of the parameter.

get_component(full_name: str) → MetadatableWithName

Recursively get a component of the instrument by full_name.

Parameters:: full_name – The name of the component to get.
Returns:: The component with the given name.
Raises:: KeyError – If the component does not exist.

get_idn() → dict[str, str | None]

Parse a standard VISA *IDN? response into an ID dict.

Even though this is the VISA standard, it applies to various other types as well, such as IPInstruments, so it is included here in the Instrument base class.

Override this if your instrument does not support *IDN? or returns a nonstandard IDN string. This string is supposed to be a comma-separated list of vendor, model, serial, and firmware, but semicolon and colon are also common separators so we accept them here as well.

Returns:: A dict containing vendor, model, serial, and firmware.

classmethod instances() → list[T]

Get all currently defined instances of this instrument class.

You can use this to get the objects back if you lose track of them, and it’s also used by the test system to find objects to test against.

Returns:: A list of instances.

invalidate_cache() → None

Invalidate the cache of all parameters on the instrument. Calling this method will recursively mark the cache of all parameters on the instrument and any parameter on instrument modules as invalid.

This is useful if you have performed manual operations (e.g. using the frontpanel) which changes the state of the instrument outside QCoDeS.

This in turn means that the next snapshot of the instrument will trigger a (potentially slow) reread of all parameters of the instrument if you pass update=None to snapshot.

static is_valid(instr_instance: Instrument) → bool

Check if a given instance of an instrument is valid: if an instrument has been closed, its instance is not longer a “valid” instrument.

Parameters:: instr_instance – Instance of an Instrument class or its subclass.

property label: str: Nicely formatted label of the instrument.

load_metadata(metadata: Mapping[str, Any]) → None

Load metadata into this classes metadata dictionary.

Parameters:: metadata – Metadata to load.

property name: str

Full name of the instrument

This is equivalent to full_name() for backwards compatibility.

property name_parts: list[str]: A list of all the parts of the instrument name from root_instrument() to the current InstrumentModule.

omit_delegate_attrs: ClassVar[list[str]] = []: A list of attribute names (strings) to not delegate to any other dictionary or object.

property parent: InstrumentBase | None: The parent instrument. By default, this is None. Any SubInstrument should subclass this to return the parent instrument.

print_readable_snapshot(update: bool = False, max_chars: int = 80) → None

Prints a readable version of the snapshot. The readable snapshot includes the name, value and unit of each parameter. A convenience function to quickly get an overview of the status of an instrument.

Parameters:

update – If True, update the state by querying the instrument. If False, just use the latest values in memory. This argument gets passed to the snapshot function.
max_chars – the maximum number of characters per line. The readable snapshot will be cropped if this value is exceeded. Defaults to 80 to be consistent with default terminal width.

classmethod record_instance(instance: Instrument) → None

Record (a weak ref to) an instance in a class’s instance list.

Also records the instance in list of all instruments, and verifies that there are no other instruments with the same name.

This method is called after initialization of the instrument is completed.

Parameters:: instance – Instance to record.
Raises:: KeyError – If another instance with the same name is already present.

classmethod remove_instance(instance: Instrument) → None

Remove a particular instance from the record.

Parameters:: instance – The instance to remove

reset() → None: Reset instrument to factory defaults. This resets both channels.

property root_instrument: InstrumentBase

The topmost parent of this module.

For the root_instrument this is self.

set(param_name: str, value: Any) → None

Shortcut for setting a parameter from its name and new value.

Parameters:

param_name – The name of a parameter of this instrument.
value – The new value to set.

set_address(address: str) → None

Set the address for this instrument.

Parameters:: address – The visa resource name to use to connect. The address should be the actual address and just that. If you wish to change the backend for VISA, use the self.visalib attribute (and then call this function).

set_terminator(terminator: str | None) → None

Change the read terminator to use.

Parameters:: terminator – Character(s) to look for at the end of a read and to end each write command with. eg. \r\n. If None the terminator will not be set.

property short_name: str

Short name of the instrument.

For an InstrumentModule this does not include any parent names.

snapshot(update: bool | None = False) → dict[str, Any]

Decorate a snapshot dictionary with metadata. DO NOT override this method if you want metadata in the snapshot instead, override snapshot_base().

Parameters:: update – Passed to snapshot_base.
Returns:: Base snapshot.

snapshot_base(update: bool | None = True, params_to_skip_update: Sequence[str] | None = None) → dict[Any, Any]

State of the instrument as a JSON-compatible dict (everything that the custom JSON encoder class NumpyJSONEncoder supports).

Parameters:

update – If True, update the state by querying the instrument. If None only update if the state is known to be invalid. If False, just use the latest values in memory and never update.
params_to_skip_update – List of parameter names that will be skipped in update even if update is True. This is useful if you have parameters that are slow to update but can be updated in a different way (as in the qdac). If you want to skip the update of certain parameters in all snapshots, use the snapshot_get attribute of those parameters instead.

Returns:

base snapshot

Return type:

dict

validate_status(verbose: bool = False) → None

Validate the values of all gettable parameters

The validation is done for all parameters that have both a get and set method.

Parameters:: verbose – If True, then information about the parameters that are being check is printed.

write(cmd: str) → None

Write a command string with NO response to the hardware.

Subclasses that transform cmd should override this method, and in it call super().write(new_cmd). Subclasses that define a new hardware communication should instead override write_raw.

Parameters:: cmd – The string to send to the instrument.
Raises:: Exception – Wraps any underlying exception with extra context, including the command and the instrument.

write_raw(cmd: str) → None

Low-level interface to visa_handle.write.

Parameters:: cmd – The command to send to the instrument.

channels: list[Keithley2600Channel] = []

visabackend: str = visabackend

visa_handle: pyvisa.resources.MessageBasedResource = visa_handle: The VISA resource used by this instrument.

visalib: str | None = visalib

parameters: dict[str, ParameterBase] = {}: All the parameters supported by this instrument. Usually populated via add_parameter().

functions: dict[str, Function] = {}: All the functions supported by this instrument. Usually populated via add_function().

submodules: dict[str, InstrumentModule | ChannelTuple] = {}: All the submodules of this instrument such as channel lists or logical groupings of parameters. Usually populated via add_submodule().

instrument_modules: dict[str, InstrumentModule] = {}: All the InstrumentModule of this instrument Usually populated via add_submodule().

log: InstrumentLoggerAdapter = get_instrument_logger(self, __name__)

metadata: dict[str, Any] = {}

resource_manager = resource_manager: The VISA resource manager used by this instrument.

class qcodes.instrument_drivers.Keithley.Keithley2635B(name: str, address: str, **kwargs: Any)[source]

Bases: Keithley2600

QCoDeS driver for the Keithley 2635B Source-Meter

Parameters:

name – Name to use internally in QCoDeS
address – VISA resource address
**kwargs – kwargs are forwarded to base class.

Methods:

`__del__`()	Close the instrument and remove its instance record.
`__getitem__`(key)	Delegate instrument['name'] to parameter or function 'name'.
`__getstate__`()	Prevent pickling instruments, and give a nice error message.
`__repr__`()	Simplified repr giving just the class and name.
`add_function`(name, **kwargs)	Bind one `Function` to this instrument.
`add_parameter`(name[, parameter_class])	Bind one Parameter to this instrument.
`add_submodule`(name, submodule)	Bind one submodule to this instrument.
`ask`(cmd)	Override of normal ask.
`ask_raw`(cmd)	Low-level interface to `visa_handle.ask`.
`call`(func_name, *args)	Shortcut for calling a function from its name.
`close`()	Disconnect and irreversibly tear down the instrument.
`close_all`()	Try to close all instruments registered in `_all_instruments` This is handy for use with atexit to ensure that all instruments are closed when a python session is closed.
`connect_message`([idn_param, begin_time])	Print a standard message on initial connection to an instrument.
`device_clear`()	Clear the buffers of the device
`display_clear`()	This function clears the display, but also leaves it in user mode
`display_normal`()	Set the display to the default mode
`exist`(name[, instrument_class])	Check if an instrument with a given names exists (i.e. is already instantiated).
`exit_key`()	Get back the normal screen after an error: send an EXIT key press event
`find_instrument`(name[, instrument_class])	Find an existing instrument by name.
`get`(param_name)	Shortcut for getting a parameter from its name.
`get_component`(full_name)	Recursively get a component of the instrument by full_name.
`get_idn`()	Parse a standard VISA `*IDN?` response into an ID dict.
`instances`()	Get all currently defined instances of this instrument class.
`invalidate_cache`()	Invalidate the cache of all parameters on the instrument.
`is_valid`(instr_instance)	Check if a given instance of an instrument is valid: if an instrument has been closed, its instance is not longer a "valid" instrument.
`load_metadata`(metadata)	Load metadata into this classes metadata dictionary.
`print_readable_snapshot`([update, max_chars])	Prints a readable version of the snapshot.
`record_instance`(instance)	Record (a weak ref to) an instance in a class's instance list.
`remove_instance`(instance)	Remove a particular instance from the record.
`reset`()	Reset instrument to factory defaults.
`set`(param_name, value)	Shortcut for setting a parameter from its name and new value.
`set_address`(address)	Set the address for this instrument.
`set_terminator`(terminator)	Change the read terminator to use.
`snapshot`([update])	Decorate a snapshot dictionary with metadata.
`snapshot_base`([update, params_to_skip_update])	State of the instrument as a JSON-compatible dict (everything that the custom JSON encoder class `NumpyJSONEncoder` supports).
`validate_status`([verbose])	Validate the values of all gettable parameters
`write`(cmd)	Write a command string with NO response to the hardware.
`write_raw`(cmd)	Low-level interface to `visa_handle.write`.

Attributes:

`ancestors`	Ancestors in the form of a list of `InstrumentBase`
`delegate_attr_dicts`	A list of names (strings) of dictionaries which are (or will be) attributes of `self`, whose keys should be treated as attributes of `self`.
`delegate_attr_objects`	A list of names (strings) of objects which are (or will be) attributes of `self`, whose attributes should be passed through to `self`.
`full_name`	Full name of the instrument.
`label`	Nicely formatted label of the instrument.
`name`	Full name of the instrument
`name_parts`	A list of all the parts of the instrument name from `root_instrument()` to the current `InstrumentModule`.
`omit_delegate_attrs`	A list of attribute names (strings) to not delegate to any other dictionary or object.
`parent`	The parent instrument.
`root_instrument`	The topmost parent of this module.
`short_name`	Short name of the instrument.
`visa_handle`	The VISA resource used by this instrument.
`resource_manager`	The VISA resource manager used by this instrument.
`parameters`	All the parameters supported by this instrument.
`functions`	All the functions supported by this instrument.
`submodules`	All the submodules of this instrument such as channel lists or logical groupings of parameters.
`instrument_modules`	All the `InstrumentModule` of this instrument Usually populated via `add_submodule()`.

__del__() → None: Close the instrument and remove its instance record.

__getitem__(key: str) → Callable[..., Any] | Parameter: Delegate instrument[‘name’] to parameter or function ‘name’.

__getstate__() → None: Prevent pickling instruments, and give a nice error message.

__repr__() → str: Simplified repr giving just the class and name.

add_function(name: str, **kwargs: Any) → None

Bind one Function to this instrument.

Instrument subclasses can call this repeatedly in their __init__ for every real function of the instrument.

This functionality is meant for simple cases, principally things that map to simple commands like *RST (reset) or those with just a few arguments. It requires a fixed argument count, and positional args only.

Note

We do not recommend the usage of Function for any new driver. Function does not add any significant features over a method defined on the class.

Parameters:

name – How the Function will be stored within instrument.Functions and also how you address it using the shortcut methods: instrument.call(func_name, *args) etc.
**kwargs – constructor kwargs for Function

Raises:

KeyError – If this instrument already has a function with this name.

add_parameter(name: str, parameter_class: type[ParameterBase] | None = None, **kwargs: Any) → None

Bind one Parameter to this instrument.

Instrument subclasses can call this repeatedly in their __init__ for every real parameter of the instrument.

In this sense, parameters are the state variables of the instrument, anything the user can set and/or get.

Parameters:

name – How the parameter will be stored within parameters and also how you address it using the shortcut methods: instrument.set(param_name, value) etc.
parameter_class – You can construct the parameter out of any class. Default parameters.Parameter.
**kwargs – Constructor arguments for parameter_class.

Raises:

KeyError – If this instrument already has a parameter with this name and the parameter being replaced is not an abstract parameter.
ValueError – If there is an existing abstract parameter and the unit of the new parameter is inconsistent with the existing one.

add_submodule(name: str, submodule: InstrumentModule | ChannelTuple) → None

Bind one submodule to this instrument.

Instrument subclasses can call this repeatedly in their __init__ method for every submodule of the instrument.

Submodules can effectively be considered as instruments within the main instrument, and should at minimum be snapshottable. For example, they can be used to either store logical groupings of parameters, which may or may not be repeated, or channel lists. They should either be an instance of an InstrumentModule or a ChannelTuple.

Parameters:

name – How the submodule will be stored within instrument.submodules and also how it can be addressed.
submodule – The submodule to be stored.

Raises:

KeyError – If this instrument already contains a submodule with this name.
TypeError – If the submodule that we are trying to add is not an instance of an Metadatable object.

property ancestors: tuple[InstrumentBase, ...]

Ancestors in the form of a list of InstrumentBase

The list starts with the current module then the parent and the parents parent until the root instrument is reached.

ask(cmd: str) → str: Override of normal ask. This is important, since queries to the instrument must be wrapped in ‘print()’

ask_raw(cmd: str) → str

Low-level interface to visa_handle.ask.

Parameters:: cmd – The command to send to the instrument.
Returns:: The instrument’s response.
Return type:: str

call(func_name: str, *args: Any) → Any

Shortcut for calling a function from its name.

Parameters:

func_name – The name of a function of this instrument.
*args – any arguments to the function.

Returns:

The return value of the function.

close() → None: Disconnect and irreversibly tear down the instrument.

classmethod close_all() → None

Try to close all instruments registered in _all_instruments This is handy for use with atexit to ensure that all instruments are closed when a python session is closed.

Examples

>>> atexit.register(qc.Instrument.close_all())

connect_message(idn_param: str = 'IDN', begin_time: float | None = None) → None

Print a standard message on initial connection to an instrument.

Parameters:

idn_param – Name of parameter that returns ID dict. Default IDN.
begin_time – time.time() when init started. Default is self._t0, set at start of Instrument.__init__.

delegate_attr_dicts: ClassVar[list[str]] = ['parameters', 'functions', 'submodules']: A list of names (strings) of dictionaries which are (or will be) attributes of self, whose keys should be treated as attributes of self.

delegate_attr_objects: ClassVar[list[str]] = []: A list of names (strings) of objects which are (or will be) attributes of self, whose attributes should be passed through to self.

device_clear() → None: Clear the buffers of the device

display_clear() → None: This function clears the display, but also leaves it in user mode

display_normal() → None: Set the display to the default mode

static exist(name: str, instrument_class: type[Instrument] | None = None) → bool

Check if an instrument with a given names exists (i.e. is already instantiated).

Parameters:

name – Name of the instrument.
instrument_class – The type of instrument you are looking for.

exit_key() → None: Get back the normal screen after an error: send an EXIT key press event

classmethod find_instrument(name: str, instrument_class: type[T] | None = None) → T | Instrument

Find an existing instrument by name.

Parameters:

name – Name of the instrument.
instrument_class – The type of instrument you are looking for.

Returns:

The instrument found.

Raises:

KeyError – If no instrument of that name was found, or if its reference is invalid (dead).
TypeError – If a specific class was requested but a different type was found.

property full_name: str

Full name of the instrument.

For an InstrumentModule this includes all parents separated by _

get(param_name: str) → Any

Shortcut for getting a parameter from its name.

Parameters:: param_name – The name of a parameter of this instrument.
Returns:: The current value of the parameter.

get_component(full_name: str) → MetadatableWithName

Recursively get a component of the instrument by full_name.

Parameters:: full_name – The name of the component to get.
Returns:: The component with the given name.
Raises:: KeyError – If the component does not exist.

get_idn() → dict[str, str | None]

Parse a standard VISA *IDN? response into an ID dict.

Even though this is the VISA standard, it applies to various other types as well, such as IPInstruments, so it is included here in the Instrument base class.

Override this if your instrument does not support *IDN? or returns a nonstandard IDN string. This string is supposed to be a comma-separated list of vendor, model, serial, and firmware, but semicolon and colon are also common separators so we accept them here as well.

Returns:: A dict containing vendor, model, serial, and firmware.

classmethod instances() → list[T]

Get all currently defined instances of this instrument class.

You can use this to get the objects back if you lose track of them, and it’s also used by the test system to find objects to test against.

Returns:: A list of instances.

invalidate_cache() → None

Invalidate the cache of all parameters on the instrument. Calling this method will recursively mark the cache of all parameters on the instrument and any parameter on instrument modules as invalid.

This is useful if you have performed manual operations (e.g. using the frontpanel) which changes the state of the instrument outside QCoDeS.

This in turn means that the next snapshot of the instrument will trigger a (potentially slow) reread of all parameters of the instrument if you pass update=None to snapshot.

static is_valid(instr_instance: Instrument) → bool

Check if a given instance of an instrument is valid: if an instrument has been closed, its instance is not longer a “valid” instrument.

Parameters:: instr_instance – Instance of an Instrument class or its subclass.

property label: str: Nicely formatted label of the instrument.

load_metadata(metadata: Mapping[str, Any]) → None

Load metadata into this classes metadata dictionary.

Parameters:: metadata – Metadata to load.

property name: str

Full name of the instrument

This is equivalent to full_name() for backwards compatibility.

property name_parts: list[str]: A list of all the parts of the instrument name from root_instrument() to the current InstrumentModule.

omit_delegate_attrs: ClassVar[list[str]] = []: A list of attribute names (strings) to not delegate to any other dictionary or object.

property parent: InstrumentBase | None: The parent instrument. By default, this is None. Any SubInstrument should subclass this to return the parent instrument.

print_readable_snapshot(update: bool = False, max_chars: int = 80) → None

Prints a readable version of the snapshot. The readable snapshot includes the name, value and unit of each parameter. A convenience function to quickly get an overview of the status of an instrument.

Parameters:

update – If True, update the state by querying the instrument. If False, just use the latest values in memory. This argument gets passed to the snapshot function.
max_chars – the maximum number of characters per line. The readable snapshot will be cropped if this value is exceeded. Defaults to 80 to be consistent with default terminal width.

classmethod record_instance(instance: Instrument) → None

Record (a weak ref to) an instance in a class’s instance list.

Also records the instance in list of all instruments, and verifies that there are no other instruments with the same name.

This method is called after initialization of the instrument is completed.

Parameters:: instance – Instance to record.
Raises:: KeyError – If another instance with the same name is already present.

classmethod remove_instance(instance: Instrument) → None

Remove a particular instance from the record.

Parameters:: instance – The instance to remove

reset() → None: Reset instrument to factory defaults. This resets both channels.

property root_instrument: InstrumentBase

The topmost parent of this module.

For the root_instrument this is self.

set(param_name: str, value: Any) → None

Shortcut for setting a parameter from its name and new value.

Parameters:

param_name – The name of a parameter of this instrument.
value – The new value to set.

set_address(address: str) → None

Set the address for this instrument.

Parameters:: address – The visa resource name to use to connect. The address should be the actual address and just that. If you wish to change the backend for VISA, use the self.visalib attribute (and then call this function).

set_terminator(terminator: str | None) → None

Change the read terminator to use.

Parameters:: terminator – Character(s) to look for at the end of a read and to end each write command with. eg. \r\n. If None the terminator will not be set.

property short_name: str

Short name of the instrument.

For an InstrumentModule this does not include any parent names.

snapshot(update: bool | None = False) → dict[str, Any]

Decorate a snapshot dictionary with metadata. DO NOT override this method if you want metadata in the snapshot instead, override snapshot_base().

Parameters:: update – Passed to snapshot_base.
Returns:: Base snapshot.

snapshot_base(update: bool | None = True, params_to_skip_update: Sequence[str] | None = None) → dict[Any, Any]

State of the instrument as a JSON-compatible dict (everything that the custom JSON encoder class NumpyJSONEncoder supports).

Parameters:

update – If True, update the state by querying the instrument. If None only update if the state is known to be invalid. If False, just use the latest values in memory and never update.
params_to_skip_update – List of parameter names that will be skipped in update even if update is True. This is useful if you have parameters that are slow to update but can be updated in a different way (as in the qdac). If you want to skip the update of certain parameters in all snapshots, use the snapshot_get attribute of those parameters instead.

Returns:

base snapshot

Return type:

dict

validate_status(verbose: bool = False) → None

Validate the values of all gettable parameters

The validation is done for all parameters that have both a get and set method.

Parameters:: verbose – If True, then information about the parameters that are being check is printed.

write(cmd: str) → None

Write a command string with NO response to the hardware.

Subclasses that transform cmd should override this method, and in it call super().write(new_cmd). Subclasses that define a new hardware communication should instead override write_raw.

Parameters:: cmd – The string to send to the instrument.
Raises:: Exception – Wraps any underlying exception with extra context, including the command and the instrument.

write_raw(cmd: str) → None

Low-level interface to visa_handle.write.

Parameters:: cmd – The command to send to the instrument.

channels: list[Keithley2600Channel] = []

visabackend: str = visabackend

visa_handle: pyvisa.resources.MessageBasedResource = visa_handle: The VISA resource used by this instrument.

visalib: str | None = visalib

parameters: dict[str, ParameterBase] = {}: All the parameters supported by this instrument. Usually populated via add_parameter().

functions: dict[str, Function] = {}: All the functions supported by this instrument. Usually populated via add_function().

submodules: dict[str, InstrumentModule | ChannelTuple] = {}: All the submodules of this instrument such as channel lists or logical groupings of parameters. Usually populated via add_submodule().

instrument_modules: dict[str, InstrumentModule] = {}: All the InstrumentModule of this instrument Usually populated via add_submodule().

log: InstrumentLoggerAdapter = get_instrument_logger(self, __name__)

metadata: dict[str, Any] = {}

resource_manager = resource_manager: The VISA resource manager used by this instrument.

class qcodes.instrument_drivers.Keithley.Keithley2636B(name: str, address: str, **kwargs: Any)[source]

Bases: Keithley2600

QCoDeS driver for the Keithley 2636B Source-Meter

Parameters:

name – Name to use internally in QCoDeS
address – VISA resource address
**kwargs – kwargs are forwarded to base class.

Methods:

`__del__`()	Close the instrument and remove its instance record.
`__getitem__`(key)	Delegate instrument['name'] to parameter or function 'name'.
`__getstate__`()	Prevent pickling instruments, and give a nice error message.
`__repr__`()	Simplified repr giving just the class and name.
`add_function`(name, **kwargs)	Bind one `Function` to this instrument.
`add_parameter`(name[, parameter_class])	Bind one Parameter to this instrument.
`add_submodule`(name, submodule)	Bind one submodule to this instrument.
`ask`(cmd)	Override of normal ask.
`ask_raw`(cmd)	Low-level interface to `visa_handle.ask`.
`call`(func_name, *args)	Shortcut for calling a function from its name.
`close`()	Disconnect and irreversibly tear down the instrument.
`close_all`()	Try to close all instruments registered in `_all_instruments` This is handy for use with atexit to ensure that all instruments are closed when a python session is closed.
`connect_message`([idn_param, begin_time])	Print a standard message on initial connection to an instrument.
`device_clear`()	Clear the buffers of the device
`display_clear`()	This function clears the display, but also leaves it in user mode
`display_normal`()	Set the display to the default mode
`exist`(name[, instrument_class])	Check if an instrument with a given names exists (i.e. is already instantiated).
`exit_key`()	Get back the normal screen after an error: send an EXIT key press event
`find_instrument`(name[, instrument_class])	Find an existing instrument by name.
`get`(param_name)	Shortcut for getting a parameter from its name.
`get_component`(full_name)	Recursively get a component of the instrument by full_name.
`get_idn`()	Parse a standard VISA `*IDN?` response into an ID dict.
`instances`()	Get all currently defined instances of this instrument class.
`invalidate_cache`()	Invalidate the cache of all parameters on the instrument.
`is_valid`(instr_instance)	Check if a given instance of an instrument is valid: if an instrument has been closed, its instance is not longer a "valid" instrument.
`load_metadata`(metadata)	Load metadata into this classes metadata dictionary.
`print_readable_snapshot`([update, max_chars])	Prints a readable version of the snapshot.
`record_instance`(instance)	Record (a weak ref to) an instance in a class's instance list.
`remove_instance`(instance)	Remove a particular instance from the record.
`reset`()	Reset instrument to factory defaults.
`set`(param_name, value)	Shortcut for setting a parameter from its name and new value.
`set_address`(address)	Set the address for this instrument.
`set_terminator`(terminator)	Change the read terminator to use.
`snapshot`([update])	Decorate a snapshot dictionary with metadata.
`snapshot_base`([update, params_to_skip_update])	State of the instrument as a JSON-compatible dict (everything that the custom JSON encoder class `NumpyJSONEncoder` supports).
`validate_status`([verbose])	Validate the values of all gettable parameters
`write`(cmd)	Write a command string with NO response to the hardware.
`write_raw`(cmd)	Low-level interface to `visa_handle.write`.

Attributes:

`ancestors`	Ancestors in the form of a list of `InstrumentBase`
`delegate_attr_dicts`	A list of names (strings) of dictionaries which are (or will be) attributes of `self`, whose keys should be treated as attributes of `self`.
`delegate_attr_objects`	A list of names (strings) of objects which are (or will be) attributes of `self`, whose attributes should be passed through to `self`.
`full_name`	Full name of the instrument.
`label`	Nicely formatted label of the instrument.
`name`	Full name of the instrument
`name_parts`	A list of all the parts of the instrument name from `root_instrument()` to the current `InstrumentModule`.
`omit_delegate_attrs`	A list of attribute names (strings) to not delegate to any other dictionary or object.
`parent`	The parent instrument.
`root_instrument`	The topmost parent of this module.
`short_name`	Short name of the instrument.
`visa_handle`	The VISA resource used by this instrument.
`resource_manager`	The VISA resource manager used by this instrument.
`parameters`	All the parameters supported by this instrument.
`functions`	All the functions supported by this instrument.
`submodules`	All the submodules of this instrument such as channel lists or logical groupings of parameters.
`instrument_modules`	All the `InstrumentModule` of this instrument Usually populated via `add_submodule()`.

__del__() → None: Close the instrument and remove its instance record.

__getitem__(key: str) → Callable[..., Any] | Parameter: Delegate instrument[‘name’] to parameter or function ‘name’.

__getstate__() → None: Prevent pickling instruments, and give a nice error message.

__repr__() → str: Simplified repr giving just the class and name.

add_function(name: str, **kwargs: Any) → None

Bind one Function to this instrument.

Instrument subclasses can call this repeatedly in their __init__ for every real function of the instrument.

This functionality is meant for simple cases, principally things that map to simple commands like *RST (reset) or those with just a few arguments. It requires a fixed argument count, and positional args only.

Note

We do not recommend the usage of Function for any new driver. Function does not add any significant features over a method defined on the class.

Parameters:

name – How the Function will be stored within instrument.Functions and also how you address it using the shortcut methods: instrument.call(func_name, *args) etc.
**kwargs – constructor kwargs for Function

Raises:

KeyError – If this instrument already has a function with this name.

add_parameter(name: str, parameter_class: type[ParameterBase] | None = None, **kwargs: Any) → None

Bind one Parameter to this instrument.

Instrument subclasses can call this repeatedly in their __init__ for every real parameter of the instrument.

In this sense, parameters are the state variables of the instrument, anything the user can set and/or get.

Parameters:

name – How the parameter will be stored within parameters and also how you address it using the shortcut methods: instrument.set(param_name, value) etc.
parameter_class – You can construct the parameter out of any class. Default parameters.Parameter.
**kwargs – Constructor arguments for parameter_class.

Raises:

KeyError – If this instrument already has a parameter with this name and the parameter being replaced is not an abstract parameter.
ValueError – If there is an existing abstract parameter and the unit of the new parameter is inconsistent with the existing one.

add_submodule(name: str, submodule: InstrumentModule | ChannelTuple) → None

Bind one submodule to this instrument.

Instrument subclasses can call this repeatedly in their __init__ method for every submodule of the instrument.

Submodules can effectively be considered as instruments within the main instrument, and should at minimum be snapshottable. For example, they can be used to either store logical groupings of parameters, which may or may not be repeated, or channel lists. They should either be an instance of an InstrumentModule or a ChannelTuple.

Parameters:

name – How the submodule will be stored within instrument.submodules and also how it can be addressed.
submodule – The submodule to be stored.

Raises:

KeyError – If this instrument already contains a submodule with this name.
TypeError – If the submodule that we are trying to add is not an instance of an Metadatable object.

property ancestors: tuple[InstrumentBase, ...]

Ancestors in the form of a list of InstrumentBase

The list starts with the current module then the parent and the parents parent until the root instrument is reached.

ask(cmd: str) → str: Override of normal ask. This is important, since queries to the instrument must be wrapped in ‘print()’

ask_raw(cmd: str) → str

Low-level interface to visa_handle.ask.

Parameters:: cmd – The command to send to the instrument.
Returns:: The instrument’s response.
Return type:: str

call(func_name: str, *args: Any) → Any

Shortcut for calling a function from its name.

Parameters:

func_name – The name of a function of this instrument.
*args – any arguments to the function.

Returns:

The return value of the function.

close() → None: Disconnect and irreversibly tear down the instrument.

classmethod close_all() → None

Try to close all instruments registered in _all_instruments This is handy for use with atexit to ensure that all instruments are closed when a python session is closed.

Examples

>>> atexit.register(qc.Instrument.close_all())

connect_message(idn_param: str = 'IDN', begin_time: float | None = None) → None

Print a standard message on initial connection to an instrument.

Parameters:

idn_param – Name of parameter that returns ID dict. Default IDN.
begin_time – time.time() when init started. Default is self._t0, set at start of Instrument.__init__.

delegate_attr_dicts: ClassVar[list[str]] = ['parameters', 'functions', 'submodules']: A list of names (strings) of dictionaries which are (or will be) attributes of self, whose keys should be treated as attributes of self.

delegate_attr_objects: ClassVar[list[str]] = []: A list of names (strings) of objects which are (or will be) attributes of self, whose attributes should be passed through to self.

device_clear() → None: Clear the buffers of the device

display_clear() → None: This function clears the display, but also leaves it in user mode

display_normal() → None: Set the display to the default mode

static exist(name: str, instrument_class: type[Instrument] | None = None) → bool

Check if an instrument with a given names exists (i.e. is already instantiated).

Parameters:

name – Name of the instrument.
instrument_class – The type of instrument you are looking for.

exit_key() → None: Get back the normal screen after an error: send an EXIT key press event

classmethod find_instrument(name: str, instrument_class: type[T] | None = None) → T | Instrument

Find an existing instrument by name.

Parameters:

name – Name of the instrument.
instrument_class – The type of instrument you are looking for.

Returns:

The instrument found.

Raises:

KeyError – If no instrument of that name was found, or if its reference is invalid (dead).
TypeError – If a specific class was requested but a different type was found.

property full_name: str

Full name of the instrument.

For an InstrumentModule this includes all parents separated by _

get(param_name: str) → Any

Shortcut for getting a parameter from its name.

Parameters:: param_name – The name of a parameter of this instrument.
Returns:: The current value of the parameter.

get_component(full_name: str) → MetadatableWithName

Recursively get a component of the instrument by full_name.

Parameters:: full_name – The name of the component to get.
Returns:: The component with the given name.
Raises:: KeyError – If the component does not exist.

get_idn() → dict[str, str | None]

Parse a standard VISA *IDN? response into an ID dict.

Even though this is the VISA standard, it applies to various other types as well, such as IPInstruments, so it is included here in the Instrument base class.

Override this if your instrument does not support *IDN? or returns a nonstandard IDN string. This string is supposed to be a comma-separated list of vendor, model, serial, and firmware, but semicolon and colon are also common separators so we accept them here as well.

Returns:: A dict containing vendor, model, serial, and firmware.

classmethod instances() → list[T]

Get all currently defined instances of this instrument class.

You can use this to get the objects back if you lose track of them, and it’s also used by the test system to find objects to test against.

Returns:: A list of instances.

invalidate_cache() → None

Invalidate the cache of all parameters on the instrument. Calling this method will recursively mark the cache of all parameters on the instrument and any parameter on instrument modules as invalid.

This is useful if you have performed manual operations (e.g. using the frontpanel) which changes the state of the instrument outside QCoDeS.

This in turn means that the next snapshot of the instrument will trigger a (potentially slow) reread of all parameters of the instrument if you pass update=None to snapshot.

static is_valid(instr_instance: Instrument) → bool

Check if a given instance of an instrument is valid: if an instrument has been closed, its instance is not longer a “valid” instrument.

Parameters:: instr_instance – Instance of an Instrument class or its subclass.

property label: str: Nicely formatted label of the instrument.

load_metadata(metadata: Mapping[str, Any]) → None

Load metadata into this classes metadata dictionary.

Parameters:: metadata – Metadata to load.

property name: str

Full name of the instrument

This is equivalent to full_name() for backwards compatibility.

property name_parts: list[str]: A list of all the parts of the instrument name from root_instrument() to the current InstrumentModule.

omit_delegate_attrs: ClassVar[list[str]] = []: A list of attribute names (strings) to not delegate to any other dictionary or object.

property parent: InstrumentBase | None: The parent instrument. By default, this is None. Any SubInstrument should subclass this to return the parent instrument.

print_readable_snapshot(update: bool = False, max_chars: int = 80) → None

Prints a readable version of the snapshot. The readable snapshot includes the name, value and unit of each parameter. A convenience function to quickly get an overview of the status of an instrument.

Parameters:

update – If True, update the state by querying the instrument. If False, just use the latest values in memory. This argument gets passed to the snapshot function.
max_chars – the maximum number of characters per line. The readable snapshot will be cropped if this value is exceeded. Defaults to 80 to be consistent with default terminal width.

classmethod record_instance(instance: Instrument) → None

Record (a weak ref to) an instance in a class’s instance list.

Also records the instance in list of all instruments, and verifies that there are no other instruments with the same name.

This method is called after initialization of the instrument is completed.

Parameters:: instance – Instance to record.
Raises:: KeyError – If another instance with the same name is already present.

classmethod remove_instance(instance: Instrument) → None

Remove a particular instance from the record.

Parameters:: instance – The instance to remove

reset() → None: Reset instrument to factory defaults. This resets both channels.

property root_instrument: InstrumentBase

The topmost parent of this module.

For the root_instrument this is self.

set(param_name: str, value: Any) → None

Shortcut for setting a parameter from its name and new value.

Parameters:

param_name – The name of a parameter of this instrument.
value – The new value to set.

set_address(address: str) → None

Set the address for this instrument.

Parameters:: address – The visa resource name to use to connect. The address should be the actual address and just that. If you wish to change the backend for VISA, use the self.visalib attribute (and then call this function).

set_terminator(terminator: str | None) → None

Change the read terminator to use.

Parameters:: terminator – Character(s) to look for at the end of a read and to end each write command with. eg. \r\n. If None the terminator will not be set.

property short_name: str

Short name of the instrument.

For an InstrumentModule this does not include any parent names.

snapshot(update: bool | None = False) → dict[str, Any]

Decorate a snapshot dictionary with metadata. DO NOT override this method if you want metadata in the snapshot instead, override snapshot_base().

Parameters:: update – Passed to snapshot_base.
Returns:: Base snapshot.

snapshot_base(update: bool | None = True, params_to_skip_update: Sequence[str] | None = None) → dict[Any, Any]

State of the instrument as a JSON-compatible dict (everything that the custom JSON encoder class NumpyJSONEncoder supports).

Parameters:

update – If True, update the state by querying the instrument. If None only update if the state is known to be invalid. If False, just use the latest values in memory and never update.
params_to_skip_update – List of parameter names that will be skipped in update even if update is True. This is useful if you have parameters that are slow to update but can be updated in a different way (as in the qdac). If you want to skip the update of certain parameters in all snapshots, use the snapshot_get attribute of those parameters instead.

Returns:

base snapshot

Return type:

dict

validate_status(verbose: bool = False) → None

Validate the values of all gettable parameters

The validation is done for all parameters that have both a get and set method.

Parameters:: verbose – If True, then information about the parameters that are being check is printed.

write(cmd: str) → None

Write a command string with NO response to the hardware.

Subclasses that transform cmd should override this method, and in it call super().write(new_cmd). Subclasses that define a new hardware communication should instead override write_raw.

Parameters:: cmd – The string to send to the instrument.
Raises:: Exception – Wraps any underlying exception with extra context, including the command and the instrument.

write_raw(cmd: str) → None

Low-level interface to visa_handle.write.

Parameters:: cmd – The command to send to the instrument.

channels: list[Keithley2600Channel] = []

visabackend: str = visabackend

visa_handle: pyvisa.resources.MessageBasedResource = visa_handle: The VISA resource used by this instrument.

visalib: str | None = visalib

parameters: dict[str, ParameterBase] = {}: All the parameters supported by this instrument. Usually populated via add_parameter().

functions: dict[str, Function] = {}: All the functions supported by this instrument. Usually populated via add_function().

submodules: dict[str, InstrumentModule | ChannelTuple] = {}: All the submodules of this instrument such as channel lists or logical groupings of parameters. Usually populated via add_submodule().

instrument_modules: dict[str, InstrumentModule] = {}: All the InstrumentModule of this instrument Usually populated via add_submodule().

log: InstrumentLoggerAdapter = get_instrument_logger(self, __name__)

metadata: dict[str, Any] = {}

resource_manager = resource_manager: The VISA resource manager used by this instrument.

class qcodes.instrument_drivers.Keithley.Keithley3706A(name: str, address: str, terminator: str = '\n', **kwargs: Any)[source]

Bases: VisaInstrument

This is the QCoDeS instrument driver for the Keithley 3706A-SNFP System Switch.

Parameters:

name – Name to use internally in QCoDeS
address – VISA resource address
terminator – Character to terminate messages with.
**kwargs – kwargs are forwarded to base class.

Methods:

`reset_channel`(val)	Resets the specified channels to factory default settings.
`open_channel`(val)	Opens the specified channels and backplane relays.
`close_channel`(val)	Closes the channels and backplane relays.
`exclusive_close`(val)	Closes the specified channels such that any presently closed channels opens if they are not in the specified by the parameter.
`exclusive_slot_close`(val)	Closes the specified channels on the associated slots abd opens any other channels if they are not specified by the parameter.
`get_closed_channels`(val)	Queries for the closed channels.
`set_forbidden_channels`(val)	Prevents the closing of specified channels and backplane relays.
`get_forbidden_channels`(val)	Returns a string that lists the channels and backplane relays that are forbidden to close.
`clear_forbidden_channels`(val)	Clears the list of channels that are forbidden to close.
`set_delay`(val, delay_time)	Sets an additional delay time for the specified channels.
`get_delay`(val)	Queries for the delay times.
`set_backplane`(val, backplane)	Sets the analog backplane relays to use with given channels when they are used in switching applications.
`get_backplane`(val)	Lists the backplane relays that are controlled in switching applications for specified channels.
`get_channels`()	This function returns the name of the matrix channels.
`get_channels_by_slot`(slot_no)	Returns the channel names of a given slot.
`get_analog_backplane_specifiers`()	Returns a list of comma separated strings representing available analog backplane relays.
`connect_row_to_columns`(slot_id, row_id, columns)	A convenient function that connects given columns to a row of a slot and opens the formed channels.
`disconnect_row_from_columns`(slot_id, row_id, ...)	A convenient function that disconnects given columns to a row of a slot and closes the formed channels.
`connect_column_to_rows`(slot_id, column_id, rows)	A convenient function that connects given rows to a column of a slot and opens the formed channels.
`disconnect_column_from_rows`(slot_id, ...)	A convenient function that disconnects given rows to a column of a slot and closes the formed channels.
`get_idn`()	Overwrites the generic QCoDeS get IDN method.
`get_switch_cards`()	Returns a list of dictionaries listing the properties of the installed switch cards including the slot number tha it is installed, model, firmware version and serial number.
`get_available_memory`()	Returns the amount of memory that is currently available for storing scripts, configurations and channel patterns.
`get_interlock_state`()	A function that collects the interlock status of the installed cards.
`get_interlock_state_by_slot`(slot)
`get_ip_address`()	Returns the current IP address of the instrument.
`reset_local_network`()	Resets the local network (LAN).
`save_setup`([val])	Saves the present setup.
`load_setup`(val)	Loads the settings from a saved setup.
`connect_message`([idn_param, begin_time])	Overwrites the generic QCoDeS instrument connect message.
`ask`(cmd)	Override of normal ask.
`__del__`()	Close the instrument and remove its instance record.
`__getitem__`(key)	Delegate instrument['name'] to parameter or function 'name'.
`__getstate__`()	Prevent pickling instruments, and give a nice error message.
`__repr__`()	Simplified repr giving just the class and name.
`add_function`(name, **kwargs)	Bind one `Function` to this instrument.
`add_parameter`(name[, parameter_class])	Bind one Parameter to this instrument.
`add_submodule`(name, submodule)	Bind one submodule to this instrument.
`ask_raw`(cmd)	Low-level interface to `visa_handle.ask`.
`call`(func_name, *args)	Shortcut for calling a function from its name.
`close`()	Disconnect and irreversibly tear down the instrument.
`close_all`()	Try to close all instruments registered in `_all_instruments` This is handy for use with atexit to ensure that all instruments are closed when a python session is closed.
`device_clear`()	Clear the buffers of the device
`exist`(name[, instrument_class])	Check if an instrument with a given names exists (i.e. is already instantiated).
`find_instrument`(name[, instrument_class])	Find an existing instrument by name.
`get`(param_name)	Shortcut for getting a parameter from its name.
`get_component`(full_name)	Recursively get a component of the instrument by full_name.
`instances`()	Get all currently defined instances of this instrument class.
`invalidate_cache`()	Invalidate the cache of all parameters on the instrument.
`is_valid`(instr_instance)	Check if a given instance of an instrument is valid: if an instrument has been closed, its instance is not longer a "valid" instrument.
`load_metadata`(metadata)	Load metadata into this classes metadata dictionary.
`print_readable_snapshot`([update, max_chars])	Prints a readable version of the snapshot.
`record_instance`(instance)	Record (a weak ref to) an instance in a class's instance list.
`remove_instance`(instance)	Remove a particular instance from the record.
`set`(param_name, value)	Shortcut for setting a parameter from its name and new value.
`set_address`(address)	Set the address for this instrument.
`set_terminator`(terminator)	Change the read terminator to use.
`snapshot`([update])	Decorate a snapshot dictionary with metadata.
`snapshot_base`([update, params_to_skip_update])	State of the instrument as a JSON-compatible dict (everything that the custom JSON encoder class `NumpyJSONEncoder` supports).
`validate_status`([verbose])	Validate the values of all gettable parameters
`write`(cmd)	Write a command string with NO response to the hardware.
`write_raw`(cmd)	Low-level interface to `visa_handle.write`.

Attributes:

`ancestors`	Ancestors in the form of a list of `InstrumentBase`
`delegate_attr_dicts`	A list of names (strings) of dictionaries which are (or will be) attributes of `self`, whose keys should be treated as attributes of `self`.
`delegate_attr_objects`	A list of names (strings) of objects which are (or will be) attributes of `self`, whose attributes should be passed through to `self`.
`full_name`	Full name of the instrument.
`label`	Nicely formatted label of the instrument.
`name`	Full name of the instrument
`name_parts`	A list of all the parts of the instrument name from `root_instrument()` to the current `InstrumentModule`.
`omit_delegate_attrs`	A list of attribute names (strings) to not delegate to any other dictionary or object.
`parent`	The parent instrument.
`root_instrument`	The topmost parent of this module.
`short_name`	Short name of the instrument.
`visa_handle`	The VISA resource used by this instrument.
`resource_manager`	The VISA resource manager used by this instrument.
`parameters`	All the parameters supported by this instrument.
`functions`	All the functions supported by this instrument.
`submodules`	All the submodules of this instrument such as channel lists or logical groupings of parameters.
`instrument_modules`	All the `InstrumentModule` of this instrument Usually populated via `add_submodule()`.

reset_channel(val: str) → None[source]

Resets the specified channels to factory default settings.

Parameters:: val – A string representing the channels, channel ranges, backplane relays, slots or channel patterns to be queried.

open_channel(val: str) → None[source]

Opens the specified channels and backplane relays.

Parameters:: val – A string representing the channels, channel ranges, backplane relays, slots or channel patterns to be queried.

close_channel(val: str) → None[source]

Closes the channels and backplane relays.

Parameters:: val – A string representing the channels, channel ranges, backplane relays to be queried.

exclusive_close(val: str) → None[source]

Closes the specified channels such that any presently closed channels opens if they are not in the specified by the parameter.

Parameters:: val – A string representing the channels, channel ranges, backplane relays to be queried.

exclusive_slot_close(val: str) → None[source]

Closes the specified channels on the associated slots abd opens any other channels if they are not specified by the parameter.

Parameters:: val – A string representing the channels, channel ranges, backplane relays to be queried.

get_closed_channels(val: str) → list[str] | None[source]

Queries for the closed channels.

Parameters:: val – A string representing the channels, backplane relays or channel patterns to be queried.

set_forbidden_channels(val: str) → None[source]

Prevents the closing of specified channels and backplane relays.

Parameters:: val – A string representing channels and backplane relays to make forbidden to close.

get_forbidden_channels(val: str) → str[source]

Returns a string that lists the channels and backplane relays that are forbidden to close.

Parameters:: val – A string representing the channels, backplane relays or channel patterns to be queried to see if they are forbidden to close.

clear_forbidden_channels(val: str) → None[source]

Clears the list of channels that are forbidden to close.

Parameters:: val – A string representing the channels that will no longer be listed as forbidden to close.

set_delay(val: str, delay_time: float) → None[source]

Sets an additional delay time for the specified channels.

Parameters:

val – A string representing the channels for which there will be an additional delay time.
delay_time – Delay time for the specified channels in seconds.

get_delay(val: str) → list[float][source]

Queries for the delay times.

Parameters:: val – A string representing the channels to query for additional delay times.

set_backplane(val: str, backplane: str) → None[source]

Sets the analog backplane relays to use with given channels when they are used in switching applications.

Parameters:

val – A string representing the list of channels to change.
backplane – A string representing the list of analog backplane relays to set for the channels specified.

get_backplane(val: str) → str[source]

Lists the backplane relays that are controlled in switching applications for specified channels.

Parameters:: val – A string representing the channels being queried.

get_channels() → list[str][source]: This function returns the name of the matrix channels. User can call this function to see the names of the available channels, in case he/she is not familiar with the naming convention. However, note that, this is a standalone helper function and the usage of channel attributes of the instrument driver does not depend on the functionality of this method.

get_channels_by_slot(slot_no: int) → list[str][source]

Returns the channel names of a given slot.

Parameters:: slot_no – An integer value specifying the slot number.

get_analog_backplane_specifiers() → list[str][source]: Returns a list of comma separated strings representing available analog backplane relays. This function should not be mixed with the get_backplane method. The latter returns backplane relays which are associated with a channel by using set_backplane method.

connect_row_to_columns(slot_id: int, row_id: int, columns: list[int]) → list[str][source]

A convenient function that connects given columns to a row of a slot and opens the formed channels.

Parameters:

slot_id – The specifier for the slot from which the row and columns will be selected.
row_id – The specifier for the row to which the provided columns will be connected.
columns – The specifiers of the columns will be connected to the provided row.

disconnect_row_from_columns(slot_id: int, row_id: int, columns: list[int]) → list[str][source]

A convenient function that disconnects given columns to a row of a slot and closes the formed channels.

Parameters:

slot_id – The specifier for the slot from which the row and columns will be selected.
row_id – The specifier for the row to which the provided columns will be disconnected.
columns – The specifiers of the columns will be disconnected from the provided row.

connect_column_to_rows(slot_id: int, column_id: int, rows: list[int]) → list[str][source]

A convenient function that connects given rows to a column of a slot and opens the formed channels.

Parameters:

slot_id – The specifier for the slot from which the row and columns will be selected.
column_id – The specifier for the column to which the provided rows will be connected.
rows – The specifiers of the rows will be connected to the provided column.

disconnect_column_from_rows(slot_id: int, column_id: int, rows: list[int]) → list[str][source]

A convenient function that disconnects given rows to a column of a slot and closes the formed channels.

Parameters:

slot_id – The specifier for the slot from which the row and columns will be selected.
column_id – The specifier for the column to which the provided rows will be disconnected.
rows – The specifiers of the rows will be disconnected from the provided column.

get_idn() → dict[str, str | None][source]: Overwrites the generic QCoDeS get IDN method. Returns a dictionary including the vendor, model, serial number and firmware version of the instrument.

get_switch_cards() → tuple[dict[str, str], ...][source]: Returns a list of dictionaries listing the properties of the installed switch cards including the slot number tha it is installed, model, firmware version and serial number.

get_available_memory() → dict[str, str | None][source]: Returns the amount of memory that is currently available for storing scripts, configurations and channel patterns.

get_interlock_state() → tuple[dict[str, str], ...][source]: A function that collects the interlock status of the installed cards. The channel relays can continue to operate even if the interlock in the corresponding slot is disengaged, one cannot perform measurements through the switching card, as the analog backplanes cannot be energized.

get_interlock_state_by_slot(slot: str | int) → int | None[source]

get_ip_address() → str[source]: Returns the current IP address of the instrument.

reset_local_network() → None[source]: Resets the local network (LAN).

save_setup(val: str | None = None) → None[source]

Saves the present setup.

Parameters:: val – An optional string representing the path and the file name to which the setup shall be saved on a USB flash drive. If not provided, the setup will be saved to the nonvolatile memory of the instrument, any previous saves will be overwritten.

load_setup(val: int | str) → None[source]

Loads the settings from a saved setup.

Parameters:: val – An integer or a string that specifies the location of saved setup. If it is 0, factory defaults load. If it is 1, the saved setup from the nonvolatile memory is recalled. Otherwise, a string specifying the relative path to the saved setup on a USB drive should be passed in.

connect_message(idn_param: str = 'IDN', begin_time: float | None = None) → None[source]: Overwrites the generic QCoDeS instrument connect message. Here, additionally, we provide information about which slots of the system switch is occupied with what kind of matrix, as well.

ask(cmd: str) → str[source]: Override of normal ask. This is important, since queries to the instrument must be wrapped in ‘print()’

__del__() → None: Close the instrument and remove its instance record.

__getitem__(key: str) → Callable[..., Any] | Parameter: Delegate instrument[‘name’] to parameter or function ‘name’.

__getstate__() → None: Prevent pickling instruments, and give a nice error message.

__repr__() → str: Simplified repr giving just the class and name.

add_function(name: str, **kwargs: Any) → None

Bind one Function to this instrument.

Instrument subclasses can call this repeatedly in their __init__ for every real function of the instrument.

This functionality is meant for simple cases, principally things that map to simple commands like *RST (reset) or those with just a few arguments. It requires a fixed argument count, and positional args only.

Note

We do not recommend the usage of Function for any new driver. Function does not add any significant features over a method defined on the class.

Parameters:

name – How the Function will be stored within instrument.Functions and also how you address it using the shortcut methods: instrument.call(func_name, *args) etc.
**kwargs – constructor kwargs for Function

Raises:

KeyError – If this instrument already has a function with this name.

add_parameter(name: str, parameter_class: type[ParameterBase] | None = None, **kwargs: Any) → None

Bind one Parameter to this instrument.

Instrument subclasses can call this repeatedly in their __init__ for every real parameter of the instrument.

In this sense, parameters are the state variables of the instrument, anything the user can set and/or get.

Parameters:

name – How the parameter will be stored within parameters and also how you address it using the shortcut methods: instrument.set(param_name, value) etc.
parameter_class – You can construct the parameter out of any class. Default parameters.Parameter.
**kwargs – Constructor arguments for parameter_class.

Raises:

KeyError – If this instrument already has a parameter with this name and the parameter being replaced is not an abstract parameter.
ValueError – If there is an existing abstract parameter and the unit of the new parameter is inconsistent with the existing one.

add_submodule(name: str, submodule: InstrumentModule | ChannelTuple) → None

Bind one submodule to this instrument.

Instrument subclasses can call this repeatedly in their __init__ method for every submodule of the instrument.

Submodules can effectively be considered as instruments within the main instrument, and should at minimum be snapshottable. For example, they can be used to either store logical groupings of parameters, which may or may not be repeated, or channel lists. They should either be an instance of an InstrumentModule or a ChannelTuple.

Parameters:

name – How the submodule will be stored within instrument.submodules and also how it can be addressed.
submodule – The submodule to be stored.

Raises:

KeyError – If this instrument already contains a submodule with this name.
TypeError – If the submodule that we are trying to add is not an instance of an Metadatable object.

property ancestors: tuple[InstrumentBase, ...]

Ancestors in the form of a list of InstrumentBase

The list starts with the current module then the parent and the parents parent until the root instrument is reached.

ask_raw(cmd: str) → str

Low-level interface to visa_handle.ask.

Parameters:: cmd – The command to send to the instrument.
Returns:: The instrument’s response.
Return type:: str

call(func_name: str, *args: Any) → Any

Shortcut for calling a function from its name.

Parameters:

func_name – The name of a function of this instrument.
*args – any arguments to the function.

Returns:

The return value of the function.

close() → None: Disconnect and irreversibly tear down the instrument.

classmethod close_all() → None

Try to close all instruments registered in _all_instruments This is handy for use with atexit to ensure that all instruments are closed when a python session is closed.

Examples

>>> atexit.register(qc.Instrument.close_all())

delegate_attr_dicts: ClassVar[list[str]] = ['parameters', 'functions', 'submodules']: A list of names (strings) of dictionaries which are (or will be) attributes of self, whose keys should be treated as attributes of self.

delegate_attr_objects: ClassVar[list[str]] = []: A list of names (strings) of objects which are (or will be) attributes of self, whose attributes should be passed through to self.

device_clear() → None: Clear the buffers of the device

static exist(name: str, instrument_class: type[Instrument] | None = None) → bool

Check if an instrument with a given names exists (i.e. is already instantiated).

Parameters:

name – Name of the instrument.
instrument_class – The type of instrument you are looking for.

classmethod find_instrument(name: str, instrument_class: type[T] | None = None) → T | Instrument

Find an existing instrument by name.

Parameters:

name – Name of the instrument.
instrument_class – The type of instrument you are looking for.

Returns:

The instrument found.

Raises:

KeyError – If no instrument of that name was found, or if its reference is invalid (dead).
TypeError – If a specific class was requested but a different type was found.

property full_name: str

Full name of the instrument.

For an InstrumentModule this includes all parents separated by _

get(param_name: str) → Any

Shortcut for getting a parameter from its name.

Parameters:: param_name – The name of a parameter of this instrument.
Returns:: The current value of the parameter.

get_component(full_name: str) → MetadatableWithName

Recursively get a component of the instrument by full_name.

Parameters:: full_name – The name of the component to get.
Returns:: The component with the given name.
Raises:: KeyError – If the component does not exist.

classmethod instances() → list[T]

Get all currently defined instances of this instrument class.

You can use this to get the objects back if you lose track of them, and it’s also used by the test system to find objects to test against.

Returns:: A list of instances.

invalidate_cache() → None

Invalidate the cache of all parameters on the instrument. Calling this method will recursively mark the cache of all parameters on the instrument and any parameter on instrument modules as invalid.

This is useful if you have performed manual operations (e.g. using the frontpanel) which changes the state of the instrument outside QCoDeS.

This in turn means that the next snapshot of the instrument will trigger a (potentially slow) reread of all parameters of the instrument if you pass update=None to snapshot.

static is_valid(instr_instance: Instrument) → bool

Check if a given instance of an instrument is valid: if an instrument has been closed, its instance is not longer a “valid” instrument.

Parameters:: instr_instance – Instance of an Instrument class or its subclass.

property label: str: Nicely formatted label of the instrument.

load_metadata(metadata: Mapping[str, Any]) → None

Load metadata into this classes metadata dictionary.

Parameters:: metadata – Metadata to load.

property name: str

Full name of the instrument

This is equivalent to full_name() for backwards compatibility.

property name_parts: list[str]: A list of all the parts of the instrument name from root_instrument() to the current InstrumentModule.

omit_delegate_attrs: ClassVar[list[str]] = []: A list of attribute names (strings) to not delegate to any other dictionary or object.

property parent: InstrumentBase | None: The parent instrument. By default, this is None. Any SubInstrument should subclass this to return the parent instrument.

print_readable_snapshot(update: bool = False, max_chars: int = 80) → None

Prints a readable version of the snapshot. The readable snapshot includes the name, value and unit of each parameter. A convenience function to quickly get an overview of the status of an instrument.

Parameters:

update – If True, update the state by querying the instrument. If False, just use the latest values in memory. This argument gets passed to the snapshot function.
max_chars – the maximum number of characters per line. The readable snapshot will be cropped if this value is exceeded. Defaults to 80 to be consistent with default terminal width.

classmethod record_instance(instance: Instrument) → None

Record (a weak ref to) an instance in a class’s instance list.

Also records the instance in list of all instruments, and verifies that there are no other instruments with the same name.

This method is called after initialization of the instrument is completed.

Parameters:: instance – Instance to record.
Raises:: KeyError – If another instance with the same name is already present.

classmethod remove_instance(instance: Instrument) → None

Remove a particular instance from the record.

Parameters:: instance – The instance to remove

property root_instrument: InstrumentBase

The topmost parent of this module.

For the root_instrument this is self.

set(param_name: str, value: Any) → None

Shortcut for setting a parameter from its name and new value.

Parameters:

param_name – The name of a parameter of this instrument.
value – The new value to set.

set_address(address: str) → None

Set the address for this instrument.

Parameters:: address – The visa resource name to use to connect. The address should be the actual address and just that. If you wish to change the backend for VISA, use the self.visalib attribute (and then call this function).

set_terminator(terminator: str | None) → None

Change the read terminator to use.

Parameters:: terminator – Character(s) to look for at the end of a read and to end each write command with. eg. \r\n. If None the terminator will not be set.

property short_name: str

Short name of the instrument.

For an InstrumentModule this does not include any parent names.

snapshot(update: bool | None = False) → dict[str, Any]

Decorate a snapshot dictionary with metadata. DO NOT override this method if you want metadata in the snapshot instead, override snapshot_base().

Parameters:: update – Passed to snapshot_base.
Returns:: Base snapshot.

snapshot_base(update: bool | None = True, params_to_skip_update: Sequence[str] | None = None) → dict[Any, Any]

State of the instrument as a JSON-compatible dict (everything that the custom JSON encoder class NumpyJSONEncoder supports).

Parameters:

update – If True, update the state by querying the instrument. If None only update if the state is known to be invalid. If False, just use the latest values in memory and never update.
params_to_skip_update – List of parameter names that will be skipped in update even if update is True. This is useful if you have parameters that are slow to update but can be updated in a different way (as in the qdac). If you want to skip the update of certain parameters in all snapshots, use the snapshot_get attribute of those parameters instead.

Returns:

base snapshot

Return type:

dict

validate_status(verbose: bool = False) → None

Validate the values of all gettable parameters

The validation is done for all parameters that have both a get and set method.

Parameters:: verbose – If True, then information about the parameters that are being check is printed.

write(cmd: str) → None

Write a command string with NO response to the hardware.

Subclasses that transform cmd should override this method, and in it call super().write(new_cmd). Subclasses that define a new hardware communication should instead override write_raw.

Parameters:: cmd – The string to send to the instrument.
Raises:: Exception – Wraps any underlying exception with extra context, including the command and the instrument.

write_raw(cmd: str) → None

Low-level interface to visa_handle.write.

Parameters:: cmd – The command to send to the instrument.

visabackend: str = visabackend

visa_handle: pyvisa.resources.MessageBasedResource = visa_handle: The VISA resource used by this instrument.

visalib: str | None = visalib

parameters: dict[str, ParameterBase] = {}: All the parameters supported by this instrument. Usually populated via add_parameter().

functions: dict[str, Function] = {}: All the functions supported by this instrument. Usually populated via add_function().

submodules: dict[str, InstrumentModule | ChannelTuple] = {}: All the submodules of this instrument such as channel lists or logical groupings of parameters. Usually populated via add_submodule().

instrument_modules: dict[str, InstrumentModule] = {}: All the InstrumentModule of this instrument Usually populated via add_submodule().

log: InstrumentLoggerAdapter = get_instrument_logger(self, __name__)

metadata: dict[str, Any] = {}

resource_manager = resource_manager: The VISA resource manager used by this instrument.

exception qcodes.instrument_drivers.Keithley.Keithley3706AInvalidValue[source]

Bases: Exception

add_note(): Exception.add_note(note) – add a note to the exception

args

with_traceback(): Exception.with_traceback(tb) – set self.__traceback__ to tb and return self.

exception qcodes.instrument_drivers.Keithley.Keithley3706AUnknownOrEmptySlot[source]

Bases: Exception

add_note(): Exception.add_note(note) – add a note to the exception

args

with_traceback(): Exception.with_traceback(tb) – set self.__traceback__ to tb and return self.

class qcodes.instrument_drivers.Keithley.Keithley6500(name: str, address: str, reset_device: bool = False, **kwargs: Any)[source]

Bases: VisaInstrument

Driver for the Keithley 6500 multimeter. Based on the Keithley 2000 driver,

commands have been adapted for the Keithley 6500. This driver does not contain all commands available, but only the ones most commonly used.

Status: beta-version.

Parameters:

name – The name used internally by QCoDeS in the DataSet.
address – The VISA device address.
reset_device – Reset the device on startup if true.
**kwargs – kwargs are forwarded to base class.

Methods:

`reset`()	Reset the device
`__del__`()	Close the instrument and remove its instance record.
`__getitem__`(key)	Delegate instrument['name'] to parameter or function 'name'.
`__getstate__`()	Prevent pickling instruments, and give a nice error message.
`__repr__`()	Simplified repr giving just the class and name.
`add_function`(name, **kwargs)	Bind one `Function` to this instrument.
`add_parameter`(name[, parameter_class])	Bind one Parameter to this instrument.
`add_submodule`(name, submodule)	Bind one submodule to this instrument.
`ask`(cmd)	Write a command string to the hardware and return a response.
`ask_raw`(cmd)	Low-level interface to `visa_handle.ask`.
`call`(func_name, *args)	Shortcut for calling a function from its name.
`close`()	Disconnect and irreversibly tear down the instrument.
`close_all`()	Try to close all instruments registered in `_all_instruments` This is handy for use with atexit to ensure that all instruments are closed when a python session is closed.
`connect_message`([idn_param, begin_time])	Print a standard message on initial connection to an instrument.
`device_clear`()	Clear the buffers of the device
`exist`(name[, instrument_class])	Check if an instrument with a given names exists (i.e. is already instantiated).
`find_instrument`(name[, instrument_class])	Find an existing instrument by name.
`get`(param_name)	Shortcut for getting a parameter from its name.
`get_component`(full_name)	Recursively get a component of the instrument by full_name.
`get_idn`()	Parse a standard VISA `*IDN?` response into an ID dict.
`instances`()	Get all currently defined instances of this instrument class.
`invalidate_cache`()	Invalidate the cache of all parameters on the instrument.
`is_valid`(instr_instance)	Check if a given instance of an instrument is valid: if an instrument has been closed, its instance is not longer a "valid" instrument.
`load_metadata`(metadata)	Load metadata into this classes metadata dictionary.
`print_readable_snapshot`([update, max_chars])	Prints a readable version of the snapshot.
`record_instance`(instance)	Record (a weak ref to) an instance in a class's instance list.
`remove_instance`(instance)	Remove a particular instance from the record.
`set`(param_name, value)	Shortcut for setting a parameter from its name and new value.
`set_address`(address)	Set the address for this instrument.
`set_terminator`(terminator)	Change the read terminator to use.
`snapshot`([update])	Decorate a snapshot dictionary with metadata.
`snapshot_base`([update, params_to_skip_update])	State of the instrument as a JSON-compatible dict (everything that the custom JSON encoder class `NumpyJSONEncoder` supports).
`validate_status`([verbose])	Validate the values of all gettable parameters
`write`(cmd)	Write a command string with NO response to the hardware.
`write_raw`(cmd)	Low-level interface to `visa_handle.write`.

Attributes:

`ancestors`	Ancestors in the form of a list of `InstrumentBase`
`delegate_attr_dicts`	A list of names (strings) of dictionaries which are (or will be) attributes of `self`, whose keys should be treated as attributes of `self`.
`delegate_attr_objects`	A list of names (strings) of objects which are (or will be) attributes of `self`, whose attributes should be passed through to `self`.
`full_name`	Full name of the instrument.
`label`	Nicely formatted label of the instrument.
`name`	Full name of the instrument
`name_parts`	A list of all the parts of the instrument name from `root_instrument()` to the current `InstrumentModule`.
`omit_delegate_attrs`	A list of attribute names (strings) to not delegate to any other dictionary or object.
`parent`	The parent instrument.
`root_instrument`	The topmost parent of this module.
`short_name`	Short name of the instrument.
`visa_handle`	The VISA resource used by this instrument.
`resource_manager`	The VISA resource manager used by this instrument.
`parameters`	All the parameters supported by this instrument.
`functions`	All the functions supported by this instrument.
`submodules`	All the submodules of this instrument such as channel lists or logical groupings of parameters.
`instrument_modules`	All the `InstrumentModule` of this instrument Usually populated via `add_submodule()`.

reset() → None[source]: Reset the device

__del__() → None: Close the instrument and remove its instance record.

__getitem__(key: str) → Callable[..., Any] | Parameter: Delegate instrument[‘name’] to parameter or function ‘name’.

__getstate__() → None: Prevent pickling instruments, and give a nice error message.

__repr__() → str: Simplified repr giving just the class and name.

add_function(name: str, **kwargs: Any) → None

Bind one Function to this instrument.

Instrument subclasses can call this repeatedly in their __init__ for every real function of the instrument.

This functionality is meant for simple cases, principally things that map to simple commands like *RST (reset) or those with just a few arguments. It requires a fixed argument count, and positional args only.

Note

We do not recommend the usage of Function for any new driver. Function does not add any significant features over a method defined on the class.

Parameters:

name – How the Function will be stored within instrument.Functions and also how you address it using the shortcut methods: instrument.call(func_name, *args) etc.
**kwargs – constructor kwargs for Function

Raises:

KeyError – If this instrument already has a function with this name.

add_parameter(name: str, parameter_class: type[ParameterBase] | None = None, **kwargs: Any) → None

Bind one Parameter to this instrument.

Instrument subclasses can call this repeatedly in their __init__ for every real parameter of the instrument.

In this sense, parameters are the state variables of the instrument, anything the user can set and/or get.

Parameters:

name – How the parameter will be stored within parameters and also how you address it using the shortcut methods: instrument.set(param_name, value) etc.
parameter_class – You can construct the parameter out of any class. Default parameters.Parameter.
**kwargs – Constructor arguments for parameter_class.

Raises:

KeyError – If this instrument already has a parameter with this name and the parameter being replaced is not an abstract parameter.
ValueError – If there is an existing abstract parameter and the unit of the new parameter is inconsistent with the existing one.

add_submodule(name: str, submodule: InstrumentModule | ChannelTuple) → None

Bind one submodule to this instrument.

Instrument subclasses can call this repeatedly in their __init__ method for every submodule of the instrument.

Submodules can effectively be considered as instruments within the main instrument, and should at minimum be snapshottable. For example, they can be used to either store logical groupings of parameters, which may or may not be repeated, or channel lists. They should either be an instance of an InstrumentModule or a ChannelTuple.

Parameters:

name – How the submodule will be stored within instrument.submodules and also how it can be addressed.
submodule – The submodule to be stored.

Raises:

KeyError – If this instrument already contains a submodule with this name.
TypeError – If the submodule that we are trying to add is not an instance of an Metadatable object.

property ancestors: tuple[InstrumentBase, ...]

Ancestors in the form of a list of InstrumentBase

The list starts with the current module then the parent and the parents parent until the root instrument is reached.

ask(cmd: str) → str

Write a command string to the hardware and return a response.

Subclasses that transform cmd should override this method, and in it call super().ask(new_cmd). Subclasses that define a new hardware communication should instead override ask_raw.

Parameters:: cmd – The string to send to the instrument.
Returns:: response
Raises:: Exception – Wraps any underlying exception with extra context, including the command and the instrument.

ask_raw(cmd: str) → str

Low-level interface to visa_handle.ask.

Parameters:: cmd – The command to send to the instrument.
Returns:: The instrument’s response.
Return type:: str

call(func_name: str, *args: Any) → Any

Shortcut for calling a function from its name.

Parameters:

func_name – The name of a function of this instrument.
*args – any arguments to the function.

Returns:

The return value of the function.

close() → None: Disconnect and irreversibly tear down the instrument.

classmethod close_all() → None

Try to close all instruments registered in _all_instruments This is handy for use with atexit to ensure that all instruments are closed when a python session is closed.

Examples

>>> atexit.register(qc.Instrument.close_all())

connect_message(idn_param: str = 'IDN', begin_time: float | None = None) → None

Print a standard message on initial connection to an instrument.

Parameters:

idn_param – Name of parameter that returns ID dict. Default IDN.
begin_time – time.time() when init started. Default is self._t0, set at start of Instrument.__init__.

delegate_attr_dicts: ClassVar[list[str]] = ['parameters', 'functions', 'submodules']: A list of names (strings) of dictionaries which are (or will be) attributes of self, whose keys should be treated as attributes of self.

delegate_attr_objects: ClassVar[list[str]] = []: A list of names (strings) of objects which are (or will be) attributes of self, whose attributes should be passed through to self.

device_clear() → None: Clear the buffers of the device

static exist(name: str, instrument_class: type[Instrument] | None = None) → bool

Check if an instrument with a given names exists (i.e. is already instantiated).

Parameters:

name – Name of the instrument.
instrument_class – The type of instrument you are looking for.

classmethod find_instrument(name: str, instrument_class: type[T] | None = None) → T | Instrument

Find an existing instrument by name.

Parameters:

name – Name of the instrument.
instrument_class – The type of instrument you are looking for.

Returns:

The instrument found.

Raises:

KeyError – If no instrument of that name was found, or if its reference is invalid (dead).
TypeError – If a specific class was requested but a different type was found.

property full_name: str

Full name of the instrument.

For an InstrumentModule this includes all parents separated by _

get(param_name: str) → Any

Shortcut for getting a parameter from its name.

Parameters:: param_name – The name of a parameter of this instrument.
Returns:: The current value of the parameter.

get_component(full_name: str) → MetadatableWithName

Recursively get a component of the instrument by full_name.

Parameters:: full_name – The name of the component to get.
Returns:: The component with the given name.
Raises:: KeyError – If the component does not exist.

get_idn() → dict[str, str | None]

Parse a standard VISA *IDN? response into an ID dict.

Even though this is the VISA standard, it applies to various other types as well, such as IPInstruments, so it is included here in the Instrument base class.

Override this if your instrument does not support *IDN? or returns a nonstandard IDN string. This string is supposed to be a comma-separated list of vendor, model, serial, and firmware, but semicolon and colon are also common separators so we accept them here as well.

Returns:: A dict containing vendor, model, serial, and firmware.

classmethod instances() → list[T]

Get all currently defined instances of this instrument class.

You can use this to get the objects back if you lose track of them, and it’s also used by the test system to find objects to test against.

Returns:: A list of instances.

invalidate_cache() → None

Invalidate the cache of all parameters on the instrument. Calling this method will recursively mark the cache of all parameters on the instrument and any parameter on instrument modules as invalid.

This is useful if you have performed manual operations (e.g. using the frontpanel) which changes the state of the instrument outside QCoDeS.

This in turn means that the next snapshot of the instrument will trigger a (potentially slow) reread of all parameters of the instrument if you pass update=None to snapshot.

static is_valid(instr_instance: Instrument) → bool

Check if a given instance of an instrument is valid: if an instrument has been closed, its instance is not longer a “valid” instrument.

Parameters:: instr_instance – Instance of an Instrument class or its subclass.

property label: str: Nicely formatted label of the instrument.

load_metadata(metadata: Mapping[str, Any]) → None

Load metadata into this classes metadata dictionary.

Parameters:: metadata – Metadata to load.

property name: str

Full name of the instrument

This is equivalent to full_name() for backwards compatibility.

property name_parts: list[str]: A list of all the parts of the instrument name from root_instrument() to the current InstrumentModule.

omit_delegate_attrs: ClassVar[list[str]] = []: A list of attribute names (strings) to not delegate to any other dictionary or object.

property parent: InstrumentBase | None: The parent instrument. By default, this is None. Any SubInstrument should subclass this to return the parent instrument.

print_readable_snapshot(update: bool = False, max_chars: int = 80) → None

Prints a readable version of the snapshot. The readable snapshot includes the name, value and unit of each parameter. A convenience function to quickly get an overview of the status of an instrument.

Parameters:

update – If True, update the state by querying the instrument. If False, just use the latest values in memory. This argument gets passed to the snapshot function.
max_chars – the maximum number of characters per line. The readable snapshot will be cropped if this value is exceeded. Defaults to 80 to be consistent with default terminal width.

classmethod record_instance(instance: Instrument) → None

Record (a weak ref to) an instance in a class’s instance list.

Also records the instance in list of all instruments, and verifies that there are no other instruments with the same name.

This method is called after initialization of the instrument is completed.

Parameters:: instance – Instance to record.
Raises:: KeyError – If another instance with the same name is already present.

classmethod remove_instance(instance: Instrument) → None

Remove a particular instance from the record.

Parameters:: instance – The instance to remove

property root_instrument: InstrumentBase

The topmost parent of this module.

For the root_instrument this is self.

set(param_name: str, value: Any) → None

Shortcut for setting a parameter from its name and new value.

Parameters:

param_name – The name of a parameter of this instrument.
value – The new value to set.

set_address(address: str) → None

Set the address for this instrument.

Parameters:: address – The visa resource name to use to connect. The address should be the actual address and just that. If you wish to change the backend for VISA, use the self.visalib attribute (and then call this function).

set_terminator(terminator: str | None) → None

Change the read terminator to use.

Parameters:: terminator – Character(s) to look for at the end of a read and to end each write command with. eg. \r\n. If None the terminator will not be set.

property short_name: str

Short name of the instrument.

For an InstrumentModule this does not include any parent names.

snapshot(update: bool | None = False) → dict[str, Any]

Decorate a snapshot dictionary with metadata. DO NOT override this method if you want metadata in the snapshot instead, override snapshot_base().

Parameters:: update – Passed to snapshot_base.
Returns:: Base snapshot.

snapshot_base(update: bool | None = True, params_to_skip_update: Sequence[str] | None = None) → dict[Any, Any]

State of the instrument as a JSON-compatible dict (everything that the custom JSON encoder class NumpyJSONEncoder supports).

Parameters:

update – If True, update the state by querying the instrument. If None only update if the state is known to be invalid. If False, just use the latest values in memory and never update.
params_to_skip_update – List of parameter names that will be skipped in update even if update is True. This is useful if you have parameters that are slow to update but can be updated in a different way (as in the qdac). If you want to skip the update of certain parameters in all snapshots, use the snapshot_get attribute of those parameters instead.

Returns:

base snapshot

Return type:

dict

validate_status(verbose: bool = False) → None

Validate the values of all gettable parameters

The validation is done for all parameters that have both a get and set method.

Parameters:: verbose – If True, then information about the parameters that are being check is printed.

write(cmd: str) → None

Write a command string with NO response to the hardware.

Subclasses that transform cmd should override this method, and in it call super().write(new_cmd). Subclasses that define a new hardware communication should instead override write_raw.

Parameters:: cmd – The string to send to the instrument.
Raises:: Exception – Wraps any underlying exception with extra context, including the command and the instrument.

write_raw(cmd: str) → None

Low-level interface to visa_handle.write.

Parameters:: cmd – The command to send to the instrument.

visabackend: str = visabackend

visa_handle: pyvisa.resources.MessageBasedResource = visa_handle: The VISA resource used by this instrument.

visalib: str | None = visalib

parameters: dict[str, ParameterBase] = {}: All the parameters supported by this instrument. Usually populated via add_parameter().

functions: dict[str, Function] = {}: All the functions supported by this instrument. Usually populated via add_function().

submodules: dict[str, InstrumentModule | ChannelTuple] = {}: All the submodules of this instrument such as channel lists or logical groupings of parameters. Usually populated via add_submodule().

instrument_modules: dict[str, InstrumentModule] = {}: All the InstrumentModule of this instrument Usually populated via add_submodule().

log: InstrumentLoggerAdapter = get_instrument_logger(self, __name__)

metadata: dict[str, Any] = {}

resource_manager = resource_manager: The VISA resource manager used by this instrument.

exception qcodes.instrument_drivers.Keithley.Keithley6500CommandSetError[source]

Bases: Exception

add_note(): Exception.add_note(note) – add a note to the exception

args

with_traceback(): Exception.with_traceback(tb) – set self.__traceback__ to tb and return self.

class qcodes.instrument_drivers.Keithley.Keithley7510(name: str, address: str, terminator: str = '\n', **kwargs: Any)[source]

Bases: VisaInstrument

The QCoDeS driver for the Keithley 7510 DMM

Create an instance of the instrument.

Parameters:

name – Name of the instrument instance
address – Visa-resolvable instrument address
terminator – Character to terminate messages with.
**kwargs – kwargs are forwarded to base class.

Attributes:

`sense`	We have different sense modules depending on the sense function.
`digi_sense`	We have different sense modules depending on the sense function.
`ancestors`	Ancestors in the form of a list of `InstrumentBase`
`delegate_attr_dicts`	A list of names (strings) of dictionaries which are (or will be) attributes of `self`, whose keys should be treated as attributes of `self`.
`delegate_attr_objects`	A list of names (strings) of objects which are (or will be) attributes of `self`, whose attributes should be passed through to `self`.
`full_name`	Full name of the instrument.
`label`	Nicely formatted label of the instrument.
`name`	Full name of the instrument
`name_parts`	A list of all the parts of the instrument name from `root_instrument()` to the current `InstrumentModule`.
`omit_delegate_attrs`	A list of attribute names (strings) to not delegate to any other dictionary or object.
`parent`	The parent instrument.
`root_instrument`	The topmost parent of this module.
`short_name`	Short name of the instrument.
`visa_handle`	The VISA resource used by this instrument.
`resource_manager`	The VISA resource manager used by this instrument.
`parameters`	All the parameters supported by this instrument.
`functions`	All the functions supported by this instrument.
`submodules`	All the submodules of this instrument such as channel lists or logical groupings of parameters.
`instrument_modules`	All the `InstrumentModule` of this instrument Usually populated via `add_submodule()`.

Methods:

`buffer`(name[, size, style])
`initiate`()	This command starts the trigger model.
`wait`()	This command postpones the execution of subsequent commands until all previous overlapped commands are finished.
`clear_status`()	This command clears the event registers of the Questionable Event and Operation Event Register set.
`reset`()	Returns the instrument to default settings, cancels all pending commands.
`__del__`()	Close the instrument and remove its instance record.
`__getitem__`(key)	Delegate instrument['name'] to parameter or function 'name'.
`__getstate__`()	Prevent pickling instruments, and give a nice error message.
`__repr__`()	Simplified repr giving just the class and name.
`add_function`(name, **kwargs)	Bind one `Function` to this instrument.
`add_parameter`(name[, parameter_class])	Bind one Parameter to this instrument.
`add_submodule`(name, submodule)	Bind one submodule to this instrument.
`ask`(cmd)	Write a command string to the hardware and return a response.
`ask_raw`(cmd)	Low-level interface to `visa_handle.ask`.
`call`(func_name, *args)	Shortcut for calling a function from its name.
`close`()	Disconnect and irreversibly tear down the instrument.
`close_all`()	Try to close all instruments registered in `_all_instruments` This is handy for use with atexit to ensure that all instruments are closed when a python session is closed.
`connect_message`([idn_param, begin_time])	Print a standard message on initial connection to an instrument.
`device_clear`()	Clear the buffers of the device
`exist`(name[, instrument_class])	Check if an instrument with a given names exists (i.e. is already instantiated).
`find_instrument`(name[, instrument_class])	Find an existing instrument by name.
`get`(param_name)	Shortcut for getting a parameter from its name.
`get_component`(full_name)	Recursively get a component of the instrument by full_name.
`get_idn`()	Parse a standard VISA `*IDN?` response into an ID dict.
`instances`()	Get all currently defined instances of this instrument class.
`invalidate_cache`()	Invalidate the cache of all parameters on the instrument.
`is_valid`(instr_instance)	Check if a given instance of an instrument is valid: if an instrument has been closed, its instance is not longer a "valid" instrument.
`load_metadata`(metadata)	Load metadata into this classes metadata dictionary.
`print_readable_snapshot`([update, max_chars])	Prints a readable version of the snapshot.
`record_instance`(instance)	Record (a weak ref to) an instance in a class's instance list.
`remove_instance`(instance)	Remove a particular instance from the record.
`set`(param_name, value)	Shortcut for setting a parameter from its name and new value.
`set_address`(address)	Set the address for this instrument.
`set_terminator`(terminator)	Change the read terminator to use.
`snapshot`([update])	Decorate a snapshot dictionary with metadata.
`snapshot_base`([update, params_to_skip_update])	State of the instrument as a JSON-compatible dict (everything that the custom JSON encoder class `NumpyJSONEncoder` supports).
`validate_status`([verbose])	Validate the values of all gettable parameters
`write`(cmd)	Write a command string with NO response to the hardware.
`write_raw`(cmd)	Low-level interface to `visa_handle.write`.

property sense: Keithley7510Sense

We have different sense modules depending on the sense function.

Return the correct source module based on the sense function.

property digi_sense: Keithley7510DigitizeSense

We have different sense modules depending on the sense function.

Return the correct source module based on the sense function.

buffer(name: str, size: int | None = None, style: str = '') → Keithley7510Buffer[source]

initiate() → None[source]: This command starts the trigger model.

wait() → None[source]: This command postpones the execution of subsequent commands until all previous overlapped commands are finished.

clear_status() → None[source]: This command clears the event registers of the Questionable Event and Operation Event Register set. It does not affect the Questionable Event Enable or Operation Event Enable registers.

reset() → None[source]: Returns the instrument to default settings, cancels all pending commands.

__del__() → None: Close the instrument and remove its instance record.

__getitem__(key: str) → Callable[..., Any] | Parameter: Delegate instrument[‘name’] to parameter or function ‘name’.

__getstate__() → None: Prevent pickling instruments, and give a nice error message.

__repr__() → str: Simplified repr giving just the class and name.

add_function(name: str, **kwargs: Any) → None

Bind one Function to this instrument.

Instrument subclasses can call this repeatedly in their __init__ for every real function of the instrument.

This functionality is meant for simple cases, principally things that map to simple commands like *RST (reset) or those with just a few arguments. It requires a fixed argument count, and positional args only.

Note

We do not recommend the usage of Function for any new driver. Function does not add any significant features over a method defined on the class.

Parameters:

name – How the Function will be stored within instrument.Functions and also how you address it using the shortcut methods: instrument.call(func_name, *args) etc.
**kwargs – constructor kwargs for Function

Raises:

KeyError – If this instrument already has a function with this name.

add_parameter(name: str, parameter_class: type[ParameterBase] | None = None, **kwargs: Any) → None

Bind one Parameter to this instrument.

Instrument subclasses can call this repeatedly in their __init__ for every real parameter of the instrument.

In this sense, parameters are the state variables of the instrument, anything the user can set and/or get.

Parameters:

name – How the parameter will be stored within parameters and also how you address it using the shortcut methods: instrument.set(param_name, value) etc.
parameter_class – You can construct the parameter out of any class. Default parameters.Parameter.
**kwargs – Constructor arguments for parameter_class.

Raises:

KeyError – If this instrument already has a parameter with this name and the parameter being replaced is not an abstract parameter.
ValueError – If there is an existing abstract parameter and the unit of the new parameter is inconsistent with the existing one.

add_submodule(name: str, submodule: InstrumentModule | ChannelTuple) → None

Bind one submodule to this instrument.

Instrument subclasses can call this repeatedly in their __init__ method for every submodule of the instrument.

Submodules can effectively be considered as instruments within the main instrument, and should at minimum be snapshottable. For example, they can be used to either store logical groupings of parameters, which may or may not be repeated, or channel lists. They should either be an instance of an InstrumentModule or a ChannelTuple.

Parameters:

name – How the submodule will be stored within instrument.submodules and also how it can be addressed.
submodule – The submodule to be stored.

Raises:

KeyError – If this instrument already contains a submodule with this name.
TypeError – If the submodule that we are trying to add is not an instance of an Metadatable object.

property ancestors: tuple[InstrumentBase, ...]

Ancestors in the form of a list of InstrumentBase

The list starts with the current module then the parent and the parents parent until the root instrument is reached.

ask(cmd: str) → str

Write a command string to the hardware and return a response.

Subclasses that transform cmd should override this method, and in it call super().ask(new_cmd). Subclasses that define a new hardware communication should instead override ask_raw.

Parameters:: cmd – The string to send to the instrument.
Returns:: response
Raises:: Exception – Wraps any underlying exception with extra context, including the command and the instrument.

ask_raw(cmd: str) → str

Low-level interface to visa_handle.ask.

Parameters:: cmd – The command to send to the instrument.
Returns:: The instrument’s response.
Return type:: str

call(func_name: str, *args: Any) → Any

Shortcut for calling a function from its name.

Parameters:

func_name – The name of a function of this instrument.
*args – any arguments to the function.

Returns:

The return value of the function.

close() → None: Disconnect and irreversibly tear down the instrument.

classmethod close_all() → None

Try to close all instruments registered in _all_instruments This is handy for use with atexit to ensure that all instruments are closed when a python session is closed.

Examples

>>> atexit.register(qc.Instrument.close_all())

connect_message(idn_param: str = 'IDN', begin_time: float | None = None) → None

Print a standard message on initial connection to an instrument.

Parameters:

idn_param – Name of parameter that returns ID dict. Default IDN.
begin_time – time.time() when init started. Default is self._t0, set at start of Instrument.__init__.

delegate_attr_dicts: ClassVar[list[str]] = ['parameters', 'functions', 'submodules']: A list of names (strings) of dictionaries which are (or will be) attributes of self, whose keys should be treated as attributes of self.

delegate_attr_objects: ClassVar[list[str]] = []: A list of names (strings) of objects which are (or will be) attributes of self, whose attributes should be passed through to self.

device_clear() → None: Clear the buffers of the device

static exist(name: str, instrument_class: type[Instrument] | None = None) → bool

Check if an instrument with a given names exists (i.e. is already instantiated).

Parameters:

name – Name of the instrument.
instrument_class – The type of instrument you are looking for.

classmethod find_instrument(name: str, instrument_class: type[T] | None = None) → T | Instrument

Find an existing instrument by name.

Parameters:

name – Name of the instrument.
instrument_class – The type of instrument you are looking for.

Returns:

The instrument found.

Raises:

KeyError – If no instrument of that name was found, or if its reference is invalid (dead).
TypeError – If a specific class was requested but a different type was found.

property full_name: str

Full name of the instrument.

For an InstrumentModule this includes all parents separated by _

get(param_name: str) → Any

Shortcut for getting a parameter from its name.

Parameters:: param_name – The name of a parameter of this instrument.
Returns:: The current value of the parameter.

get_component(full_name: str) → MetadatableWithName

Recursively get a component of the instrument by full_name.

Parameters:: full_name – The name of the component to get.
Returns:: The component with the given name.
Raises:: KeyError – If the component does not exist.

get_idn() → dict[str, str | None]

Parse a standard VISA *IDN? response into an ID dict.

Even though this is the VISA standard, it applies to various other types as well, such as IPInstruments, so it is included here in the Instrument base class.

Override this if your instrument does not support *IDN? or returns a nonstandard IDN string. This string is supposed to be a comma-separated list of vendor, model, serial, and firmware, but semicolon and colon are also common separators so we accept them here as well.

Returns:: A dict containing vendor, model, serial, and firmware.

classmethod instances() → list[T]

Get all currently defined instances of this instrument class.

You can use this to get the objects back if you lose track of them, and it’s also used by the test system to find objects to test against.

Returns:: A list of instances.

invalidate_cache() → None

Invalidate the cache of all parameters on the instrument. Calling this method will recursively mark the cache of all parameters on the instrument and any parameter on instrument modules as invalid.

This is useful if you have performed manual operations (e.g. using the frontpanel) which changes the state of the instrument outside QCoDeS.

This in turn means that the next snapshot of the instrument will trigger a (potentially slow) reread of all parameters of the instrument if you pass update=None to snapshot.

static is_valid(instr_instance: Instrument) → bool

Check if a given instance of an instrument is valid: if an instrument has been closed, its instance is not longer a “valid” instrument.

Parameters:: instr_instance – Instance of an Instrument class or its subclass.

property label: str: Nicely formatted label of the instrument.

load_metadata(metadata: Mapping[str, Any]) → None

Load metadata into this classes metadata dictionary.

Parameters:: metadata – Metadata to load.

property name: str

Full name of the instrument

This is equivalent to full_name() for backwards compatibility.

property name_parts: list[str]: A list of all the parts of the instrument name from root_instrument() to the current InstrumentModule.

omit_delegate_attrs: ClassVar[list[str]] = []: A list of attribute names (strings) to not delegate to any other dictionary or object.

property parent: InstrumentBase | None: The parent instrument. By default, this is None. Any SubInstrument should subclass this to return the parent instrument.

print_readable_snapshot(update: bool = False, max_chars: int = 80) → None

Prints a readable version of the snapshot. The readable snapshot includes the name, value and unit of each parameter. A convenience function to quickly get an overview of the status of an instrument.

Parameters:

update – If True, update the state by querying the instrument. If False, just use the latest values in memory. This argument gets passed to the snapshot function.
max_chars – the maximum number of characters per line. The readable snapshot will be cropped if this value is exceeded. Defaults to 80 to be consistent with default terminal width.

classmethod record_instance(instance: Instrument) → None

Record (a weak ref to) an instance in a class’s instance list.

Also records the instance in list of all instruments, and verifies that there are no other instruments with the same name.

This method is called after initialization of the instrument is completed.

Parameters:: instance – Instance to record.
Raises:: KeyError – If another instance with the same name is already present.

classmethod remove_instance(instance: Instrument) → None

Remove a particular instance from the record.

Parameters:: instance – The instance to remove

property root_instrument: InstrumentBase

The topmost parent of this module.

For the root_instrument this is self.

set(param_name: str, value: Any) → None

Shortcut for setting a parameter from its name and new value.

Parameters:

param_name – The name of a parameter of this instrument.
value – The new value to set.

set_address(address: str) → None

Set the address for this instrument.

Parameters:: address – The visa resource name to use to connect. The address should be the actual address and just that. If you wish to change the backend for VISA, use the self.visalib attribute (and then call this function).

set_terminator(terminator: str | None) → None

Change the read terminator to use.

Parameters:: terminator – Character(s) to look for at the end of a read and to end each write command with. eg. \r\n. If None the terminator will not be set.

property short_name: str

Short name of the instrument.

For an InstrumentModule this does not include any parent names.

snapshot(update: bool | None = False) → dict[str, Any]

Decorate a snapshot dictionary with metadata. DO NOT override this method if you want metadata in the snapshot instead, override snapshot_base().

Parameters:: update – Passed to snapshot_base.
Returns:: Base snapshot.

snapshot_base(update: bool | None = True, params_to_skip_update: Sequence[str] | None = None) → dict[Any, Any]

State of the instrument as a JSON-compatible dict (everything that the custom JSON encoder class NumpyJSONEncoder supports).

Parameters:

update – If True, update the state by querying the instrument. If None only update if the state is known to be invalid. If False, just use the latest values in memory and never update.
params_to_skip_update – List of parameter names that will be skipped in update even if update is True. This is useful if you have parameters that are slow to update but can be updated in a different way (as in the qdac). If you want to skip the update of certain parameters in all snapshots, use the snapshot_get attribute of those parameters instead.

Returns:

base snapshot

Return type:

dict

validate_status(verbose: bool = False) → None

Validate the values of all gettable parameters

The validation is done for all parameters that have both a get and set method.

Parameters:: verbose – If True, then information about the parameters that are being check is printed.

write(cmd: str) → None

Write a command string with NO response to the hardware.

Subclasses that transform cmd should override this method, and in it call super().write(new_cmd). Subclasses that define a new hardware communication should instead override write_raw.

Parameters:: cmd – The string to send to the instrument.
Raises:: Exception – Wraps any underlying exception with extra context, including the command and the instrument.

write_raw(cmd: str) → None

Low-level interface to visa_handle.write.

Parameters:: cmd – The command to send to the instrument.

visabackend: str = visabackend

visa_handle: pyvisa.resources.MessageBasedResource = visa_handle: The VISA resource used by this instrument.

visalib: str | None = visalib

parameters: dict[str, ParameterBase] = {}: All the parameters supported by this instrument. Usually populated via add_parameter().

functions: dict[str, Function] = {}: All the functions supported by this instrument. Usually populated via add_function().

submodules: dict[str, InstrumentModule | ChannelTuple] = {}: All the submodules of this instrument such as channel lists or logical groupings of parameters. Usually populated via add_submodule().

instrument_modules: dict[str, InstrumentModule] = {}: All the InstrumentModule of this instrument Usually populated via add_submodule().

log: InstrumentLoggerAdapter = get_instrument_logger(self, __name__)

metadata: dict[str, Any] = {}

resource_manager = resource_manager: The VISA resource manager used by this instrument.

class qcodes.instrument_drivers.Keithley.Keithley7510Buffer(parent: Keithley7510, name: str, size: int | None = None, style: str = '')[source]

Bases: InstrumentChannel

Treat the reading buffer as a submodule, similar to Sense.

Attributes:

`default_buffer`
`buffer_elements`
`inverted_buffer_elements`
`available_elements`
`n_elements`
`data`
`ancestors`	Ancestors in the form of a list of `InstrumentBase`
`delegate_attr_dicts`	A list of names (strings) of dictionaries which are (or will be) attributes of `self`, whose keys should be treated as attributes of `self`.
`delegate_attr_objects`	A list of names (strings) of objects which are (or will be) attributes of `self`, whose attributes should be passed through to `self`.
`full_name`	Full name of the instrument.
`label`	Nicely formatted label of the instrument.
`name`	Full name of the instrument
`name_parts`	A list of all the parts of the instrument name from `root_instrument()` to the current `InstrumentModule`.
`omit_delegate_attrs`	A list of attribute names (strings) to not delegate to any other dictionary or object.
`parent`	The parent instrument.
`root_instrument`	The topmost parent of this module.
`short_name`	Short name of the instrument.
`parameters`	All the parameters supported by this instrument.
`functions`	All the functions supported by this instrument.
`submodules`	All the submodules of this instrument such as channel lists or logical groupings of parameters.
`instrument_modules`	All the `InstrumentModule` of this instrument Usually populated via `add_submodule()`.

Methods:

`set_setpoints`(start, stop[, label])
`get_last_reading`()	This method requests the latest reading from a reading buffer.
`clear_buffer`()	Clear the data in the buffer
`trigger_start`()	This method makes readings using the active measure function and stores them in a reading buffer.
`delete`()
`__getitem__`(key)	Delegate instrument['name'] to parameter or function 'name'.
`__getstate__`()	Prevent pickling instruments, and give a nice error message.
`__repr__`()	Custom repr to give parent information
`add_function`(name, **kwargs)	Bind one `Function` to this instrument.
`add_parameter`(name[, parameter_class])	Bind one Parameter to this instrument.
`add_submodule`(name, submodule)	Bind one submodule to this instrument.
`ask`(cmd)
`ask_raw`(cmd)
`call`(func_name, *args)	Shortcut for calling a function from its name.
`get`(param_name)	Shortcut for getting a parameter from its name.
`get_component`(full_name)	Recursively get a component of the instrument by full_name.
`invalidate_cache`()	Invalidate the cache of all parameters on the instrument.
`load_metadata`(metadata)	Load metadata into this classes metadata dictionary.
`print_readable_snapshot`([update, max_chars])	Prints a readable version of the snapshot.
`set`(param_name, value)	Shortcut for setting a parameter from its name and new value.
`snapshot`([update])	Decorate a snapshot dictionary with metadata.
`snapshot_base`([update, params_to_skip_update])	State of the instrument as a JSON-compatible dict (everything that the custom JSON encoder class `NumpyJSONEncoder` supports).
`validate_status`([verbose])	Validate the values of all gettable parameters
`write`(cmd)
`write_raw`(cmd)

default_buffer: ClassVar[set[str]] = {'defbuffer1', 'defbuffer2'}

buffer_elements: ClassVar[dict[str, str]] = {'date': 'DATE', 'fractional_seconds': 'FRACtional', 'measurement': 'READing', 'measurement_formatted': 'FORMatted', 'measurement_status': 'STATus', 'measurement_unit': 'UNIT', 'relative_time': 'RELative', 'seconds': 'SEConds', 'time': 'TIME', 'timestamp': 'TSTamp'}

inverted_buffer_elements = {'DATE': 'date', 'FORMatted': 'measurement_formatted', 'FRACtional': 'fractional_seconds', 'READing': 'measurement', 'RELative': 'relative_time', 'SEConds': 'seconds', 'STATus': 'measurement_status', 'TIME': 'time', 'TSTamp': 'timestamp', 'UNIT': 'measurement_unit'}

set_setpoints(start: Parameter, stop: Parameter, label: str | None = None) → None[source]

property available_elements: set[str]

property n_elements: int

property data: DataArray7510

get_last_reading() → str[source]: This method requests the latest reading from a reading buffer.

clear_buffer() → None[source]: Clear the data in the buffer

trigger_start() → None[source]: This method makes readings using the active measure function and stores them in a reading buffer.

delete() → None[source]

__getitem__(key: str) → Callable[..., Any] | Parameter: Delegate instrument[‘name’] to parameter or function ‘name’.

__getstate__() → None: Prevent pickling instruments, and give a nice error message.

__repr__() → str: Custom repr to give parent information

add_function(name: str, **kwargs: Any) → None

Bind one Function to this instrument.

Instrument subclasses can call this repeatedly in their __init__ for every real function of the instrument.

This functionality is meant for simple cases, principally things that map to simple commands like *RST (reset) or those with just a few arguments. It requires a fixed argument count, and positional args only.

Note

We do not recommend the usage of Function for any new driver. Function does not add any significant features over a method defined on the class.

Parameters:

name – How the Function will be stored within instrument.Functions and also how you address it using the shortcut methods: instrument.call(func_name, *args) etc.
**kwargs – constructor kwargs for Function

Raises:

KeyError – If this instrument already has a function with this name.

add_parameter(name: str, parameter_class: type[ParameterBase] | None = None, **kwargs: Any) → None

Bind one Parameter to this instrument.

Instrument subclasses can call this repeatedly in their __init__ for every real parameter of the instrument.

In this sense, parameters are the state variables of the instrument, anything the user can set and/or get.

Parameters:

name – How the parameter will be stored within parameters and also how you address it using the shortcut methods: instrument.set(param_name, value) etc.
parameter_class – You can construct the parameter out of any class. Default parameters.Parameter.
**kwargs – Constructor arguments for parameter_class.

Raises:

KeyError – If this instrument already has a parameter with this name and the parameter being replaced is not an abstract parameter.
ValueError – If there is an existing abstract parameter and the unit of the new parameter is inconsistent with the existing one.

add_submodule(name: str, submodule: InstrumentModule | ChannelTuple) → None

Bind one submodule to this instrument.

Instrument subclasses can call this repeatedly in their __init__ method for every submodule of the instrument.

Submodules can effectively be considered as instruments within the main instrument, and should at minimum be snapshottable. For example, they can be used to either store logical groupings of parameters, which may or may not be repeated, or channel lists. They should either be an instance of an InstrumentModule or a ChannelTuple.

Parameters:

name – How the submodule will be stored within instrument.submodules and also how it can be addressed.
submodule – The submodule to be stored.

Raises:

KeyError – If this instrument already contains a submodule with this name.
TypeError – If the submodule that we are trying to add is not an instance of an Metadatable object.

property ancestors: tuple[InstrumentBase, ...]

Ancestors in the form of a list of InstrumentBase

The list starts with the current module then the parent and the parents parent until the root instrument is reached.

ask(cmd: str) → str

ask_raw(cmd: str) → str

call(func_name: str, *args: Any) → Any

Shortcut for calling a function from its name.

Parameters:

func_name – The name of a function of this instrument.
*args – any arguments to the function.

Returns:

The return value of the function.

delegate_attr_dicts: ClassVar[list[str]] = ['parameters', 'functions', 'submodules']: A list of names (strings) of dictionaries which are (or will be) attributes of self, whose keys should be treated as attributes of self.

delegate_attr_objects: ClassVar[list[str]] = []: A list of names (strings) of objects which are (or will be) attributes of self, whose attributes should be passed through to self.

property full_name: str

Full name of the instrument.

For an InstrumentModule this includes all parents separated by _

get(param_name: str) → Any

Shortcut for getting a parameter from its name.

Parameters:: param_name – The name of a parameter of this instrument.
Returns:: The current value of the parameter.

get_component(full_name: str) → MetadatableWithName

Recursively get a component of the instrument by full_name.

Parameters:: full_name – The name of the component to get.
Returns:: The component with the given name.
Raises:: KeyError – If the component does not exist.

invalidate_cache() → None

Invalidate the cache of all parameters on the instrument. Calling this method will recursively mark the cache of all parameters on the instrument and any parameter on instrument modules as invalid.

This is useful if you have performed manual operations (e.g. using the frontpanel) which changes the state of the instrument outside QCoDeS.

This in turn means that the next snapshot of the instrument will trigger a (potentially slow) reread of all parameters of the instrument if you pass update=None to snapshot.

property label: str: Nicely formatted label of the instrument.

load_metadata(metadata: Mapping[str, Any]) → None

Load metadata into this classes metadata dictionary.

Parameters:: metadata – Metadata to load.

property name: str

Full name of the instrument

This is equivalent to full_name() for backwards compatibility.

property name_parts: list[str]: A list of all the parts of the instrument name from root_instrument() to the current InstrumentModule.

omit_delegate_attrs: ClassVar[list[str]] = []: A list of attribute names (strings) to not delegate to any other dictionary or object.

property parent: InstrumentBase: The parent instrument. By default, this is None. Any SubInstrument should subclass this to return the parent instrument.

print_readable_snapshot(update: bool = False, max_chars: int = 80) → None

Prints a readable version of the snapshot. The readable snapshot includes the name, value and unit of each parameter. A convenience function to quickly get an overview of the status of an instrument.

Parameters:

update – If True, update the state by querying the instrument. If False, just use the latest values in memory. This argument gets passed to the snapshot function.
max_chars – the maximum number of characters per line. The readable snapshot will be cropped if this value is exceeded. Defaults to 80 to be consistent with default terminal width.

property root_instrument: InstrumentBase

The topmost parent of this module.

For the root_instrument this is self.

set(param_name: str, value: Any) → None

Shortcut for setting a parameter from its name and new value.

Parameters:

param_name – The name of a parameter of this instrument.
value – The new value to set.

property short_name: str

Short name of the instrument.

For an InstrumentModule this does not include any parent names.

snapshot(update: bool | None = False) → dict[str, Any]

Decorate a snapshot dictionary with metadata. DO NOT override this method if you want metadata in the snapshot instead, override snapshot_base().

Parameters:: update – Passed to snapshot_base.
Returns:: Base snapshot.

snapshot_base(update: bool | None = False, params_to_skip_update: Sequence[str] | None = None) → dict[Any, Any]

State of the instrument as a JSON-compatible dict (everything that the custom JSON encoder class NumpyJSONEncoder supports).

Parameters:

update – If True, update the state by querying the instrument. If None update the state if known to be invalid. If False, just use the latest values in memory and never update state.
params_to_skip_update – List of parameter names that will be skipped in update even if update is True. This is useful if you have parameters that are slow to update but can be updated in a different way (as in the qdac). If you want to skip the update of certain parameters in all snapshots, use the snapshot_get attribute of those parameters instead.

Returns:

base snapshot

Return type:

dict

validate_status(verbose: bool = False) → None

Validate the values of all gettable parameters

The validation is done for all parameters that have both a get and set method.

Parameters:: verbose – If True, then information about the parameters that are being check is printed.

write(cmd: str) → None

write_raw(cmd: str) → None

parameters: dict[str, ParameterBase] = {}: All the parameters supported by this instrument. Usually populated via add_parameter().

functions: dict[str, Function] = {}: All the functions supported by this instrument. Usually populated via add_function().

submodules: dict[str, InstrumentModule | ChannelTuple] = {}: All the submodules of this instrument such as channel lists or logical groupings of parameters. Usually populated via add_submodule().

instrument_modules: dict[str, InstrumentModule] = {}: All the InstrumentModule of this instrument Usually populated via add_submodule().

log: InstrumentLoggerAdapter = get_instrument_logger(self, __name__)

metadata: dict[str, Any] = {}

class qcodes.instrument_drivers.Keithley.Keithley7510DigitizeSense(parent: VisaInstrument, name: str, proper_function: str)[source]

Bases: InstrumentChannel

The Digitize sense module of the Keithley 7510 DMM.

Attributes:

`function_modes`
`ancestors`	Ancestors in the form of a list of `InstrumentBase`
`delegate_attr_dicts`	A list of names (strings) of dictionaries which are (or will be) attributes of `self`, whose keys should be treated as attributes of `self`.
`delegate_attr_objects`	A list of names (strings) of objects which are (or will be) attributes of `self`, whose attributes should be passed through to `self`.
`full_name`	Full name of the instrument.
`label`	Nicely formatted label of the instrument.
`name`	Full name of the instrument
`name_parts`	A list of all the parts of the instrument name from `root_instrument()` to the current `InstrumentModule`.
`omit_delegate_attrs`	A list of attribute names (strings) to not delegate to any other dictionary or object.
`parent`	The parent instrument.
`root_instrument`	The topmost parent of this module.
`short_name`	Short name of the instrument.
`parameters`	All the parameters supported by this instrument.
`functions`	All the functions supported by this instrument.
`submodules`	All the submodules of this instrument such as channel lists or logical groupings of parameters.
`instrument_modules`	All the `InstrumentModule` of this instrument Usually populated via `add_submodule()`.

Methods:

`__getitem__`(key)	Delegate instrument['name'] to parameter or function 'name'.
`__getstate__`()	Prevent pickling instruments, and give a nice error message.
`__repr__`()	Custom repr to give parent information
`add_function`(name, **kwargs)	Bind one `Function` to this instrument.
`add_parameter`(name[, parameter_class])	Bind one Parameter to this instrument.
`add_submodule`(name, submodule)	Bind one submodule to this instrument.
`ask`(cmd)
`ask_raw`(cmd)
`call`(func_name, *args)	Shortcut for calling a function from its name.
`get`(param_name)	Shortcut for getting a parameter from its name.
`get_component`(full_name)	Recursively get a component of the instrument by full_name.
`invalidate_cache`()	Invalidate the cache of all parameters on the instrument.
`load_metadata`(metadata)	Load metadata into this classes metadata dictionary.
`print_readable_snapshot`([update, max_chars])	Prints a readable version of the snapshot.
`set`(param_name, value)	Shortcut for setting a parameter from its name and new value.
`snapshot`([update])	Decorate a snapshot dictionary with metadata.
`snapshot_base`([update, params_to_skip_update])	State of the instrument as a JSON-compatible dict (everything that the custom JSON encoder class `NumpyJSONEncoder` supports).
`validate_status`([verbose])	Validate the values of all gettable parameters
`write`(cmd)
`write_raw`(cmd)

function_modes: ClassVar[dict[str, _FunctionMode]] = {'None': {'name': '"NONE"', 'range_vals': None, 'unit': ''}, 'current': {'name': '"CURR"', 'range_vals': <Numbers 1e-05<=v<=10>, 'unit': 'V'}, 'voltage': {'name': '"VOLT"', 'range_vals': <Numbers 0.1<=v<=1000>, 'unit': 'V'}}

__getitem__(key: str) → Callable[..., Any] | Parameter: Delegate instrument[‘name’] to parameter or function ‘name’.

__getstate__() → None: Prevent pickling instruments, and give a nice error message.

__repr__() → str: Custom repr to give parent information

add_function(name: str, **kwargs: Any) → None

Bind one Function to this instrument.

Instrument subclasses can call this repeatedly in their __init__ for every real function of the instrument.

This functionality is meant for simple cases, principally things that map to simple commands like *RST (reset) or those with just a few arguments. It requires a fixed argument count, and positional args only.

Note

We do not recommend the usage of Function for any new driver. Function does not add any significant features over a method defined on the class.

Parameters:

name – How the Function will be stored within instrument.Functions and also how you address it using the shortcut methods: instrument.call(func_name, *args) etc.
**kwargs – constructor kwargs for Function

Raises:

KeyError – If this instrument already has a function with this name.

add_parameter(name: str, parameter_class: type[ParameterBase] | None = None, **kwargs: Any) → None

Bind one Parameter to this instrument.

Instrument subclasses can call this repeatedly in their __init__ for every real parameter of the instrument.

In this sense, parameters are the state variables of the instrument, anything the user can set and/or get.

Parameters:

name – How the parameter will be stored within parameters and also how you address it using the shortcut methods: instrument.set(param_name, value) etc.
parameter_class – You can construct the parameter out of any class. Default parameters.Parameter.
**kwargs – Constructor arguments for parameter_class.

Raises:

KeyError – If this instrument already has a parameter with this name and the parameter being replaced is not an abstract parameter.
ValueError – If there is an existing abstract parameter and the unit of the new parameter is inconsistent with the existing one.

add_submodule(name: str, submodule: InstrumentModule | ChannelTuple) → None

Bind one submodule to this instrument.

Instrument subclasses can call this repeatedly in their __init__ method for every submodule of the instrument.

Submodules can effectively be considered as instruments within the main instrument, and should at minimum be snapshottable. For example, they can be used to either store logical groupings of parameters, which may or may not be repeated, or channel lists. They should either be an instance of an InstrumentModule or a ChannelTuple.

Parameters:

name – How the submodule will be stored within instrument.submodules and also how it can be addressed.
submodule – The submodule to be stored.

Raises:

KeyError – If this instrument already contains a submodule with this name.
TypeError – If the submodule that we are trying to add is not an instance of an Metadatable object.

property ancestors: tuple[InstrumentBase, ...]

Ancestors in the form of a list of InstrumentBase

The list starts with the current module then the parent and the parents parent until the root instrument is reached.

ask(cmd: str) → str

ask_raw(cmd: str) → str

call(func_name: str, *args: Any) → Any

Shortcut for calling a function from its name.

Parameters:

func_name – The name of a function of this instrument.
*args – any arguments to the function.

Returns:

The return value of the function.

delegate_attr_dicts: ClassVar[list[str]] = ['parameters', 'functions', 'submodules']: A list of names (strings) of dictionaries which are (or will be) attributes of self, whose keys should be treated as attributes of self.

delegate_attr_objects: ClassVar[list[str]] = []: A list of names (strings) of objects which are (or will be) attributes of self, whose attributes should be passed through to self.

property full_name: str

Full name of the instrument.

For an InstrumentModule this includes all parents separated by _

get(param_name: str) → Any

Shortcut for getting a parameter from its name.

Parameters:: param_name – The name of a parameter of this instrument.
Returns:: The current value of the parameter.

get_component(full_name: str) → MetadatableWithName

Recursively get a component of the instrument by full_name.

Parameters:: full_name – The name of the component to get.
Returns:: The component with the given name.
Raises:: KeyError – If the component does not exist.

invalidate_cache() → None

Invalidate the cache of all parameters on the instrument. Calling this method will recursively mark the cache of all parameters on the instrument and any parameter on instrument modules as invalid.

This is useful if you have performed manual operations (e.g. using the frontpanel) which changes the state of the instrument outside QCoDeS.

This in turn means that the next snapshot of the instrument will trigger a (potentially slow) reread of all parameters of the instrument if you pass update=None to snapshot.

property label: str: Nicely formatted label of the instrument.

load_metadata(metadata: Mapping[str, Any]) → None

Load metadata into this classes metadata dictionary.

Parameters:: metadata – Metadata to load.

property name: str

Full name of the instrument

This is equivalent to full_name() for backwards compatibility.

property name_parts: list[str]: A list of all the parts of the instrument name from root_instrument() to the current InstrumentModule.

omit_delegate_attrs: ClassVar[list[str]] = []: A list of attribute names (strings) to not delegate to any other dictionary or object.

property parent: InstrumentBase: The parent instrument. By default, this is None. Any SubInstrument should subclass this to return the parent instrument.

print_readable_snapshot(update: bool = False, max_chars: int = 80) → None

Prints a readable version of the snapshot. The readable snapshot includes the name, value and unit of each parameter. A convenience function to quickly get an overview of the status of an instrument.

Parameters:

update – If True, update the state by querying the instrument. If False, just use the latest values in memory. This argument gets passed to the snapshot function.
max_chars – the maximum number of characters per line. The readable snapshot will be cropped if this value is exceeded. Defaults to 80 to be consistent with default terminal width.

property root_instrument: InstrumentBase

The topmost parent of this module.

For the root_instrument this is self.

set(param_name: str, value: Any) → None

Shortcut for setting a parameter from its name and new value.

Parameters:

param_name – The name of a parameter of this instrument.
value – The new value to set.

property short_name: str

Short name of the instrument.

For an InstrumentModule this does not include any parent names.

snapshot(update: bool | None = False) → dict[str, Any]

Decorate a snapshot dictionary with metadata. DO NOT override this method if you want metadata in the snapshot instead, override snapshot_base().

Parameters:: update – Passed to snapshot_base.
Returns:: Base snapshot.

snapshot_base(update: bool | None = False, params_to_skip_update: Sequence[str] | None = None) → dict[Any, Any]

State of the instrument as a JSON-compatible dict (everything that the custom JSON encoder class NumpyJSONEncoder supports).

Parameters:

update – If True, update the state by querying the instrument. If None update the state if known to be invalid. If False, just use the latest values in memory and never update state.
params_to_skip_update – List of parameter names that will be skipped in update even if update is True. This is useful if you have parameters that are slow to update but can be updated in a different way (as in the qdac). If you want to skip the update of certain parameters in all snapshots, use the snapshot_get attribute of those parameters instead.

Returns:

base snapshot

Return type:

dict

validate_status(verbose: bool = False) → None

Validate the values of all gettable parameters

The validation is done for all parameters that have both a get and set method.

Parameters:: verbose – If True, then information about the parameters that are being check is printed.

write(cmd: str) → None

write_raw(cmd: str) → None

parameters: dict[str, ParameterBase] = {}: All the parameters supported by this instrument. Usually populated via add_parameter().

functions: dict[str, Function] = {}: All the functions supported by this instrument. Usually populated via add_function().

submodules: dict[str, InstrumentModule | ChannelTuple] = {}: All the submodules of this instrument such as channel lists or logical groupings of parameters. Usually populated via add_submodule().

instrument_modules: dict[str, InstrumentModule] = {}: All the InstrumentModule of this instrument Usually populated via add_submodule().

log: InstrumentLoggerAdapter = get_instrument_logger(self, __name__)

metadata: dict[str, Any] = {}

class qcodes.instrument_drivers.Keithley.Keithley7510Sense(parent: VisaInstrument, name: str, proper_function: str)[source]

Bases: InstrumentChannel

The sense module of the Keithley 7510 DMM, based on the sense module of Keithley 2450 SMU.

Parameters:

parent
name
proper_function –
This can be one of modes listed in the dictionary “function_modes”, e.g., “current”, “voltage”, or “resistance”. “voltage”/”current” is for DC voltage/current. “Avoltage”/”Acurrent” is for AC voltage/current. “resistance” is for two-wire measurement of resistance. “Fresistance” is for Four-wire measurement of resistance.

All parameters and methods in this submodule should only be accessible to the user if self.parent.sense_function.get() == self._proper_function. We ensure this through the ‘sense’ property on the main driver class which returns the proper submodule for any given function mode.

Attributes:

`function_modes`
`ancestors`	Ancestors in the form of a list of `InstrumentBase`
`delegate_attr_dicts`	A list of names (strings) of dictionaries which are (or will be) attributes of `self`, whose keys should be treated as attributes of `self`.
`delegate_attr_objects`	A list of names (strings) of objects which are (or will be) attributes of `self`, whose attributes should be passed through to `self`.
`full_name`	Full name of the instrument.
`label`	Nicely formatted label of the instrument.
`name`	Full name of the instrument
`name_parts`	A list of all the parts of the instrument name from `root_instrument()` to the current `InstrumentModule`.
`omit_delegate_attrs`	A list of attribute names (strings) to not delegate to any other dictionary or object.
`parent`	The parent instrument.
`root_instrument`	The topmost parent of this module.
`short_name`	Short name of the instrument.
`parameters`	All the parameters supported by this instrument.
`functions`	All the functions supported by this instrument.
`submodules`	All the submodules of this instrument such as channel lists or logical groupings of parameters.
`instrument_modules`	All the `InstrumentModule` of this instrument Usually populated via `add_submodule()`.

Methods:

`clear_trace`([buffer_name])	Clear the data buffer
`__getitem__`(key)	Delegate instrument['name'] to parameter or function 'name'.
`__getstate__`()	Prevent pickling instruments, and give a nice error message.
`__repr__`()	Custom repr to give parent information
`add_function`(name, **kwargs)	Bind one `Function` to this instrument.
`add_parameter`(name[, parameter_class])	Bind one Parameter to this instrument.
`add_submodule`(name, submodule)	Bind one submodule to this instrument.
`ask`(cmd)
`ask_raw`(cmd)
`call`(func_name, *args)	Shortcut for calling a function from its name.
`get`(param_name)	Shortcut for getting a parameter from its name.
`get_component`(full_name)	Recursively get a component of the instrument by full_name.
`invalidate_cache`()	Invalidate the cache of all parameters on the instrument.
`load_metadata`(metadata)	Load metadata into this classes metadata dictionary.
`print_readable_snapshot`([update, max_chars])	Prints a readable version of the snapshot.
`set`(param_name, value)	Shortcut for setting a parameter from its name and new value.
`snapshot`([update])	Decorate a snapshot dictionary with metadata.
`snapshot_base`([update, params_to_skip_update])	State of the instrument as a JSON-compatible dict (everything that the custom JSON encoder class `NumpyJSONEncoder` supports).
`validate_status`([verbose])	Validate the values of all gettable parameters
`write`(cmd)
`write_raw`(cmd)

function_modes: ClassVar[dict[str, _FunctionMode]] = {'Acurrent': {'name': '"CURR:AC"', 'range_vals': <Numbers 0.001<=v<=10>, 'unit': 'A'}, 'Avoltage': {'name': '"VOLT:AC"', 'range_vals': <Numbers 0.1<=v<=700>, 'unit': 'V'}, 'Fresistance': {'name': '"FRES"', 'range_vals': <Numbers 1<=v<=1000000000.0>, 'unit': 'Ohm'}, 'current': {'name': '"CURR:DC"', 'range_vals': <Numbers 1e-05<=v<=10>, 'unit': 'V'}, 'resistance': {'name': '"RES"', 'range_vals': <Numbers 10<=v<=1000000000.0>, 'unit': 'Ohm'}, 'voltage': {'name': '"VOLT:DC"', 'range_vals': <Numbers 0.1<=v<=1000>, 'unit': 'V'}}

clear_trace(buffer_name: str = 'defbuffer1') → None[source]: Clear the data buffer

__getitem__(key: str) → Callable[..., Any] | Parameter: Delegate instrument[‘name’] to parameter or function ‘name’.

__getstate__() → None: Prevent pickling instruments, and give a nice error message.

__repr__() → str: Custom repr to give parent information

add_function(name: str, **kwargs: Any) → None

Bind one Function to this instrument.

Instrument subclasses can call this repeatedly in their __init__ for every real function of the instrument.

This functionality is meant for simple cases, principally things that map to simple commands like *RST (reset) or those with just a few arguments. It requires a fixed argument count, and positional args only.

Note

We do not recommend the usage of Function for any new driver. Function does not add any significant features over a method defined on the class.

Parameters:

name – How the Function will be stored within instrument.Functions and also how you address it using the shortcut methods: instrument.call(func_name, *args) etc.
**kwargs – constructor kwargs for Function

Raises:

KeyError – If this instrument already has a function with this name.

add_parameter(name: str, parameter_class: type[ParameterBase] | None = None, **kwargs: Any) → None

Bind one Parameter to this instrument.

Instrument subclasses can call this repeatedly in their __init__ for every real parameter of the instrument.

In this sense, parameters are the state variables of the instrument, anything the user can set and/or get.

Parameters:

name – How the parameter will be stored within parameters and also how you address it using the shortcut methods: instrument.set(param_name, value) etc.
parameter_class – You can construct the parameter out of any class. Default parameters.Parameter.
**kwargs – Constructor arguments for parameter_class.

Raises:

KeyError – If this instrument already has a parameter with this name and the parameter being replaced is not an abstract parameter.
ValueError – If there is an existing abstract parameter and the unit of the new parameter is inconsistent with the existing one.

add_submodule(name: str, submodule: InstrumentModule | ChannelTuple) → None

Bind one submodule to this instrument.

Instrument subclasses can call this repeatedly in their __init__ method for every submodule of the instrument.

Submodules can effectively be considered as instruments within the main instrument, and should at minimum be snapshottable. For example, they can be used to either store logical groupings of parameters, which may or may not be repeated, or channel lists. They should either be an instance of an InstrumentModule or a ChannelTuple.

Parameters:

name – How the submodule will be stored within instrument.submodules and also how it can be addressed.
submodule – The submodule to be stored.

Raises:

KeyError – If this instrument already contains a submodule with this name.
TypeError – If the submodule that we are trying to add is not an instance of an Metadatable object.

property ancestors: tuple[InstrumentBase, ...]

Ancestors in the form of a list of InstrumentBase

The list starts with the current module then the parent and the parents parent until the root instrument is reached.

ask(cmd: str) → str

ask_raw(cmd: str) → str

call(func_name: str, *args: Any) → Any

Shortcut for calling a function from its name.

Parameters:

func_name – The name of a function of this instrument.
*args – any arguments to the function.

Returns:

The return value of the function.

delegate_attr_dicts: ClassVar[list[str]] = ['parameters', 'functions', 'submodules']: A list of names (strings) of dictionaries which are (or will be) attributes of self, whose keys should be treated as attributes of self.

delegate_attr_objects: ClassVar[list[str]] = []: A list of names (strings) of objects which are (or will be) attributes of self, whose attributes should be passed through to self.

property full_name: str

Full name of the instrument.

For an InstrumentModule this includes all parents separated by _

get(param_name: str) → Any

Shortcut for getting a parameter from its name.

Parameters:: param_name – The name of a parameter of this instrument.
Returns:: The current value of the parameter.

get_component(full_name: str) → MetadatableWithName

Recursively get a component of the instrument by full_name.

Parameters:: full_name – The name of the component to get.
Returns:: The component with the given name.
Raises:: KeyError – If the component does not exist.

invalidate_cache() → None

Invalidate the cache of all parameters on the instrument. Calling this method will recursively mark the cache of all parameters on the instrument and any parameter on instrument modules as invalid.

This is useful if you have performed manual operations (e.g. using the frontpanel) which changes the state of the instrument outside QCoDeS.

This in turn means that the next snapshot of the instrument will trigger a (potentially slow) reread of all parameters of the instrument if you pass update=None to snapshot.

property label: str: Nicely formatted label of the instrument.

load_metadata(metadata: Mapping[str, Any]) → None

Load metadata into this classes metadata dictionary.

Parameters:: metadata – Metadata to load.

property name: str

Full name of the instrument

This is equivalent to full_name() for backwards compatibility.

property name_parts: list[str]: A list of all the parts of the instrument name from root_instrument() to the current InstrumentModule.

omit_delegate_attrs: ClassVar[list[str]] = []: A list of attribute names (strings) to not delegate to any other dictionary or object.

property parent: InstrumentBase: The parent instrument. By default, this is None. Any SubInstrument should subclass this to return the parent instrument.

print_readable_snapshot(update: bool = False, max_chars: int = 80) → None

Prints a readable version of the snapshot. The readable snapshot includes the name, value and unit of each parameter. A convenience function to quickly get an overview of the status of an instrument.

Parameters:

update – If True, update the state by querying the instrument. If False, just use the latest values in memory. This argument gets passed to the snapshot function.
max_chars – the maximum number of characters per line. The readable snapshot will be cropped if this value is exceeded. Defaults to 80 to be consistent with default terminal width.

property root_instrument: InstrumentBase

The topmost parent of this module.

For the root_instrument this is self.

set(param_name: str, value: Any) → None

Shortcut for setting a parameter from its name and new value.

Parameters:

param_name – The name of a parameter of this instrument.
value – The new value to set.

property short_name: str

Short name of the instrument.

For an InstrumentModule this does not include any parent names.

snapshot(update: bool | None = False) → dict[str, Any]

Decorate a snapshot dictionary with metadata. DO NOT override this method if you want metadata in the snapshot instead, override snapshot_base().

Parameters:: update – Passed to snapshot_base.
Returns:: Base snapshot.

snapshot_base(update: bool | None = False, params_to_skip_update: Sequence[str] | None = None) → dict[Any, Any]

State of the instrument as a JSON-compatible dict (everything that the custom JSON encoder class NumpyJSONEncoder supports).

Parameters:

update – If True, update the state by querying the instrument. If None update the state if known to be invalid. If False, just use the latest values in memory and never update state.
params_to_skip_update – List of parameter names that will be skipped in update even if update is True. This is useful if you have parameters that are slow to update but can be updated in a different way (as in the qdac). If you want to skip the update of certain parameters in all snapshots, use the snapshot_get attribute of those parameters instead.

Returns:

base snapshot

Return type:

dict

validate_status(verbose: bool = False) → None

Validate the values of all gettable parameters

The validation is done for all parameters that have both a get and set method.

Parameters:: verbose – If True, then information about the parameters that are being check is printed.

write(cmd: str) → None

write_raw(cmd: str) → None

parameters: dict[str, ParameterBase] = {}: All the parameters supported by this instrument. Usually populated via add_parameter().

functions: dict[str, Function] = {}: All the functions supported by this instrument. Usually populated via add_function().

submodules: dict[str, InstrumentModule | ChannelTuple] = {}: All the submodules of this instrument such as channel lists or logical groupings of parameters. Usually populated via add_submodule().

instrument_modules: dict[str, InstrumentModule] = {}: All the InstrumentModule of this instrument Usually populated via add_submodule().

log: InstrumentLoggerAdapter = get_instrument_logger(self, __name__)

metadata: dict[str, Any] = {}

class qcodes.instrument_drivers.Keithley.KeithleyS46(name: str, address: str, **kwargs: Any)[source]

Bases: VisaInstrument

Attributes:

`relay_names`
`channel_numbers`
`aliases`
`relay_layout`	The relay layout tells us how many channels we have per relay.
`available_channels`
`ancestors`	Ancestors in the form of a list of `InstrumentBase`
`delegate_attr_dicts`	A list of names (strings) of dictionaries which are (or will be) attributes of `self`, whose keys should be treated as attributes of `self`.
`delegate_attr_objects`	A list of names (strings) of objects which are (or will be) attributes of `self`, whose attributes should be passed through to `self`.
`full_name`	Full name of the instrument.
`label`	Nicely formatted label of the instrument.
`name`	Full name of the instrument
`name_parts`	A list of all the parts of the instrument name from `root_instrument()` to the current `InstrumentModule`.
`omit_delegate_attrs`	A list of attribute names (strings) to not delegate to any other dictionary or object.
`parent`	The parent instrument.
`root_instrument`	The topmost parent of this module.
`short_name`	Short name of the instrument.
`visa_handle`	The VISA resource used by this instrument.
`resource_manager`	The VISA resource manager used by this instrument.
`parameters`	All the parameters supported by this instrument.
`functions`	All the functions supported by this instrument.
`submodules`	All the submodules of this instrument such as channel lists or logical groupings of parameters.
`instrument_modules`	All the `InstrumentModule` of this instrument Usually populated via `add_submodule()`.

Methods:

`open_all_channels`()
`__del__`()	Close the instrument and remove its instance record.
`__getitem__`(key)	Delegate instrument['name'] to parameter or function 'name'.
`__getstate__`()	Prevent pickling instruments, and give a nice error message.
`__repr__`()	Simplified repr giving just the class and name.
`add_function`(name, **kwargs)	Bind one `Function` to this instrument.
`add_parameter`(name[, parameter_class])	Bind one Parameter to this instrument.
`add_submodule`(name, submodule)	Bind one submodule to this instrument.
`ask`(cmd)	Write a command string to the hardware and return a response.
`ask_raw`(cmd)	Low-level interface to `visa_handle.ask`.
`call`(func_name, *args)	Shortcut for calling a function from its name.
`close`()	Disconnect and irreversibly tear down the instrument.
`close_all`()	Try to close all instruments registered in `_all_instruments` This is handy for use with atexit to ensure that all instruments are closed when a python session is closed.
`connect_message`([idn_param, begin_time])	Print a standard message on initial connection to an instrument.
`device_clear`()	Clear the buffers of the device
`exist`(name[, instrument_class])	Check if an instrument with a given names exists (i.e. is already instantiated).
`find_instrument`(name[, instrument_class])	Find an existing instrument by name.
`get`(param_name)	Shortcut for getting a parameter from its name.
`get_component`(full_name)	Recursively get a component of the instrument by full_name.
`get_idn`()	Parse a standard VISA `*IDN?` response into an ID dict.
`instances`()	Get all currently defined instances of this instrument class.
`invalidate_cache`()	Invalidate the cache of all parameters on the instrument.
`is_valid`(instr_instance)	Check if a given instance of an instrument is valid: if an instrument has been closed, its instance is not longer a "valid" instrument.
`load_metadata`(metadata)	Load metadata into this classes metadata dictionary.
`print_readable_snapshot`([update, max_chars])	Prints a readable version of the snapshot.
`record_instance`(instance)	Record (a weak ref to) an instance in a class's instance list.
`remove_instance`(instance)	Remove a particular instance from the record.
`set`(param_name, value)	Shortcut for setting a parameter from its name and new value.
`set_address`(address)	Set the address for this instrument.
`set_terminator`(terminator)	Change the read terminator to use.
`snapshot`([update])	Decorate a snapshot dictionary with metadata.
`snapshot_base`([update, params_to_skip_update])	State of the instrument as a JSON-compatible dict (everything that the custom JSON encoder class `NumpyJSONEncoder` supports).
`validate_status`([verbose])	Validate the values of all gettable parameters
`write`(cmd)	Write a command string with NO response to the hardware.
`write_raw`(cmd)	Low-level interface to `visa_handle.write`.

relay_names: list[str] = ['A', 'B', 'C', 'D', 'R1', 'R2', 'R3', 'R4', 'R5', 'R6', 'R7', 'R8']

channel_numbers: ClassVar[dict[str, int]] = {'A1': 1, 'A2': 2, 'A3': 3, 'A4': 4, 'A5': 5, 'A6': 6, 'B1': 7, 'B2': 8, 'B3': 9, 'B4': 10, 'B5': 11, 'B6': 12, 'C1': 13, 'C2': 14, 'C3': 15, 'C4': 16, 'C5': 17, 'C6': 18, 'D1': 19, 'D2': 20, 'D3': 21, 'D4': 22, 'D5': 23, 'D6': 24, 'R1': 25, 'R2': 26, 'R3': 27, 'R4': 28, 'R5': 29, 'R6': 30, 'R7': 31, 'R8': 32}

aliases: ClassVar[dict[int, str]] = {1: 'A1', 2: 'A2', 3: 'A3', 4: 'A4', 5: 'A5', 6: 'A6', 7: 'B1', 8: 'B2', 9: 'B3', 10: 'B4', 11: 'B5', 12: 'B6', 13: 'C1', 14: 'C2', 15: 'C3', 16: 'C4', 17: 'C5', 18: 'C6', 19: 'D1', 20: 'D2', 21: 'D3', 22: 'D4', 23: 'D5', 24: 'D6', 25: 'R1', 26: 'R2', 27: 'R3', 28: 'R4', 29: 'R5', 30: 'R6', 31: 'R7', 32: 'R8'}

open_all_channels() → None[source]

property relay_layout: list[int]: The relay layout tells us how many channels we have per relay. Note that we can have zero channels per relay.

property available_channels: list[str]

__del__() → None: Close the instrument and remove its instance record.

__getitem__(key: str) → Callable[..., Any] | Parameter: Delegate instrument[‘name’] to parameter or function ‘name’.

__getstate__() → None: Prevent pickling instruments, and give a nice error message.

__repr__() → str: Simplified repr giving just the class and name.

add_function(name: str, **kwargs: Any) → None

Bind one Function to this instrument.

Instrument subclasses can call this repeatedly in their __init__ for every real function of the instrument.

This functionality is meant for simple cases, principally things that map to simple commands like *RST (reset) or those with just a few arguments. It requires a fixed argument count, and positional args only.

Note

We do not recommend the usage of Function for any new driver. Function does not add any significant features over a method defined on the class.

Parameters:

name – How the Function will be stored within instrument.Functions and also how you address it using the shortcut methods: instrument.call(func_name, *args) etc.
**kwargs – constructor kwargs for Function

Raises:

KeyError – If this instrument already has a function with this name.

add_parameter(name: str, parameter_class: type[ParameterBase] | None = None, **kwargs: Any) → None

Bind one Parameter to this instrument.

Instrument subclasses can call this repeatedly in their __init__ for every real parameter of the instrument.

In this sense, parameters are the state variables of the instrument, anything the user can set and/or get.

Parameters:

name – How the parameter will be stored within parameters and also how you address it using the shortcut methods: instrument.set(param_name, value) etc.
parameter_class – You can construct the parameter out of any class. Default parameters.Parameter.
**kwargs – Constructor arguments for parameter_class.

Raises:

KeyError – If this instrument already has a parameter with this name and the parameter being replaced is not an abstract parameter.
ValueError – If there is an existing abstract parameter and the unit of the new parameter is inconsistent with the existing one.

add_submodule(name: str, submodule: InstrumentModule | ChannelTuple) → None

Bind one submodule to this instrument.

Instrument subclasses can call this repeatedly in their __init__ method for every submodule of the instrument.

Submodules can effectively be considered as instruments within the main instrument, and should at minimum be snapshottable. For example, they can be used to either store logical groupings of parameters, which may or may not be repeated, or channel lists. They should either be an instance of an InstrumentModule or a ChannelTuple.

Parameters:

name – How the submodule will be stored within instrument.submodules and also how it can be addressed.
submodule – The submodule to be stored.

Raises:

KeyError – If this instrument already contains a submodule with this name.
TypeError – If the submodule that we are trying to add is not an instance of an Metadatable object.

property ancestors: tuple[InstrumentBase, ...]

Ancestors in the form of a list of InstrumentBase

The list starts with the current module then the parent and the parents parent until the root instrument is reached.

ask(cmd: str) → str

Write a command string to the hardware and return a response.

Subclasses that transform cmd should override this method, and in it call super().ask(new_cmd). Subclasses that define a new hardware communication should instead override ask_raw.

Parameters:: cmd – The string to send to the instrument.
Returns:: response
Raises:: Exception – Wraps any underlying exception with extra context, including the command and the instrument.

ask_raw(cmd: str) → str

Low-level interface to visa_handle.ask.

Parameters:: cmd – The command to send to the instrument.
Returns:: The instrument’s response.
Return type:: str

call(func_name: str, *args: Any) → Any

Shortcut for calling a function from its name.

Parameters:

func_name – The name of a function of this instrument.
*args – any arguments to the function.

Returns:

The return value of the function.

close() → None: Disconnect and irreversibly tear down the instrument.

classmethod close_all() → None

Try to close all instruments registered in _all_instruments This is handy for use with atexit to ensure that all instruments are closed when a python session is closed.

Examples

>>> atexit.register(qc.Instrument.close_all())

connect_message(idn_param: str = 'IDN', begin_time: float | None = None) → None

Print a standard message on initial connection to an instrument.

Parameters:

idn_param – Name of parameter that returns ID dict. Default IDN.
begin_time – time.time() when init started. Default is self._t0, set at start of Instrument.__init__.

delegate_attr_dicts: ClassVar[list[str]] = ['parameters', 'functions', 'submodules']: A list of names (strings) of dictionaries which are (or will be) attributes of self, whose keys should be treated as attributes of self.

delegate_attr_objects: ClassVar[list[str]] = []: A list of names (strings) of objects which are (or will be) attributes of self, whose attributes should be passed through to self.

device_clear() → None: Clear the buffers of the device

static exist(name: str, instrument_class: type[Instrument] | None = None) → bool

Check if an instrument with a given names exists (i.e. is already instantiated).

Parameters:

name – Name of the instrument.
instrument_class – The type of instrument you are looking for.

classmethod find_instrument(name: str, instrument_class: type[T] | None = None) → T | Instrument

Find an existing instrument by name.

Parameters:

name – Name of the instrument.
instrument_class – The type of instrument you are looking for.

Returns:

The instrument found.

Raises:

KeyError – If no instrument of that name was found, or if its reference is invalid (dead).
TypeError – If a specific class was requested but a different type was found.

property full_name: str

Full name of the instrument.

For an InstrumentModule this includes all parents separated by _

get(param_name: str) → Any

Shortcut for getting a parameter from its name.

Parameters:: param_name – The name of a parameter of this instrument.
Returns:: The current value of the parameter.

get_component(full_name: str) → MetadatableWithName

Recursively get a component of the instrument by full_name.

Parameters:: full_name – The name of the component to get.
Returns:: The component with the given name.
Raises:: KeyError – If the component does not exist.

get_idn() → dict[str, str | None]

Parse a standard VISA *IDN? response into an ID dict.

Even though this is the VISA standard, it applies to various other types as well, such as IPInstruments, so it is included here in the Instrument base class.

Override this if your instrument does not support *IDN? or returns a nonstandard IDN string. This string is supposed to be a comma-separated list of vendor, model, serial, and firmware, but semicolon and colon are also common separators so we accept them here as well.

Returns:: A dict containing vendor, model, serial, and firmware.

classmethod instances() → list[T]

Get all currently defined instances of this instrument class.

You can use this to get the objects back if you lose track of them, and it’s also used by the test system to find objects to test against.

Returns:: A list of instances.

invalidate_cache() → None

Invalidate the cache of all parameters on the instrument. Calling this method will recursively mark the cache of all parameters on the instrument and any parameter on instrument modules as invalid.

This is useful if you have performed manual operations (e.g. using the frontpanel) which changes the state of the instrument outside QCoDeS.

This in turn means that the next snapshot of the instrument will trigger a (potentially slow) reread of all parameters of the instrument if you pass update=None to snapshot.

static is_valid(instr_instance: Instrument) → bool

Check if a given instance of an instrument is valid: if an instrument has been closed, its instance is not longer a “valid” instrument.

Parameters:: instr_instance – Instance of an Instrument class or its subclass.

property label: str: Nicely formatted label of the instrument.

load_metadata(metadata: Mapping[str, Any]) → None

Load metadata into this classes metadata dictionary.

Parameters:: metadata – Metadata to load.

property name: str

Full name of the instrument

This is equivalent to full_name() for backwards compatibility.

property name_parts: list[str]: A list of all the parts of the instrument name from root_instrument() to the current InstrumentModule.

omit_delegate_attrs: ClassVar[list[str]] = []: A list of attribute names (strings) to not delegate to any other dictionary or object.

property parent: InstrumentBase | None: The parent instrument. By default, this is None. Any SubInstrument should subclass this to return the parent instrument.

print_readable_snapshot(update: bool = False, max_chars: int = 80) → None

Prints a readable version of the snapshot. The readable snapshot includes the name, value and unit of each parameter. A convenience function to quickly get an overview of the status of an instrument.

Parameters:

update – If True, update the state by querying the instrument. If False, just use the latest values in memory. This argument gets passed to the snapshot function.
max_chars – the maximum number of characters per line. The readable snapshot will be cropped if this value is exceeded. Defaults to 80 to be consistent with default terminal width.

classmethod record_instance(instance: Instrument) → None

Record (a weak ref to) an instance in a class’s instance list.

Also records the instance in list of all instruments, and verifies that there are no other instruments with the same name.

This method is called after initialization of the instrument is completed.

Parameters:: instance – Instance to record.
Raises:: KeyError – If another instance with the same name is already present.

classmethod remove_instance(instance: Instrument) → None

Remove a particular instance from the record.

Parameters:: instance – The instance to remove

property root_instrument: InstrumentBase

The topmost parent of this module.

For the root_instrument this is self.

set(param_name: str, value: Any) → None

Shortcut for setting a parameter from its name and new value.

Parameters:

param_name – The name of a parameter of this instrument.
value – The new value to set.

set_address(address: str) → None

Set the address for this instrument.

Parameters:: address – The visa resource name to use to connect. The address should be the actual address and just that. If you wish to change the backend for VISA, use the self.visalib attribute (and then call this function).

set_terminator(terminator: str | None) → None

Change the read terminator to use.

Parameters:: terminator – Character(s) to look for at the end of a read and to end each write command with. eg. \r\n. If None the terminator will not be set.

property short_name: str

Short name of the instrument.

For an InstrumentModule this does not include any parent names.

snapshot(update: bool | None = False) → dict[str, Any]

Decorate a snapshot dictionary with metadata. DO NOT override this method if you want metadata in the snapshot instead, override snapshot_base().

Parameters:: update – Passed to snapshot_base.
Returns:: Base snapshot.

snapshot_base(update: bool | None = True, params_to_skip_update: Sequence[str] | None = None) → dict[Any, Any]

State of the instrument as a JSON-compatible dict (everything that the custom JSON encoder class NumpyJSONEncoder supports).

Parameters:

update – If True, update the state by querying the instrument. If None only update if the state is known to be invalid. If False, just use the latest values in memory and never update.
params_to_skip_update – List of parameter names that will be skipped in update even if update is True. This is useful if you have parameters that are slow to update but can be updated in a different way (as in the qdac). If you want to skip the update of certain parameters in all snapshots, use the snapshot_get attribute of those parameters instead.

Returns:

base snapshot

Return type:

dict

validate_status(verbose: bool = False) → None

Validate the values of all gettable parameters

The validation is done for all parameters that have both a get and set method.

Parameters:: verbose – If True, then information about the parameters that are being check is printed.

write(cmd: str) → None

Write a command string with NO response to the hardware.

Subclasses that transform cmd should override this method, and in it call super().write(new_cmd). Subclasses that define a new hardware communication should instead override write_raw.

Parameters:: cmd – The string to send to the instrument.
Raises:: Exception – Wraps any underlying exception with extra context, including the command and the instrument.

write_raw(cmd: str) → None

Low-level interface to visa_handle.write.

Parameters:: cmd – The command to send to the instrument.

visabackend: str = visabackend

visa_handle: pyvisa.resources.MessageBasedResource = visa_handle: The VISA resource used by this instrument.

visalib: str | None = visalib

parameters: dict[str, ParameterBase] = {}: All the parameters supported by this instrument. Usually populated via add_parameter().

functions: dict[str, Function] = {}: All the functions supported by this instrument. Usually populated via add_function().

submodules: dict[str, InstrumentModule | ChannelTuple] = {}: All the submodules of this instrument such as channel lists or logical groupings of parameters. Usually populated via add_submodule().

instrument_modules: dict[str, InstrumentModule] = {}: All the InstrumentModule of this instrument Usually populated via add_submodule().

log: InstrumentLoggerAdapter = get_instrument_logger(self, __name__)

metadata: dict[str, Any] = {}

resource_manager = resource_manager: The VISA resource manager used by this instrument.

exception qcodes.instrument_drivers.Keithley.KeithleyS46LockAcquisitionError[source]

Bases: Exception

add_note(): Exception.add_note(note) – add a note to the exception

args

with_traceback(): Exception.with_traceback(tb) – set self.__traceback__ to tb and return self.

class qcodes.instrument_drivers.Keithley.KeithleyS46RelayLock(relay_name: str)[source]

Bases: object

The S46 either has six pole or a four pole relays. For example, channels ‘A1’ to ‘A6’ are all on relay ‘A’. However, channels ‘R1’ to ‘R8’ are all on individual relays.

Only one channel per relay may be closed at any given time to prevent degradation of RF performance and even switch damage. See page 2-11 of the manual. To enforce this, a lock mechanism has been implemented.

Methods:

`acquire`(channel_number)	Request a lock acquisition
`release`(channel_number)	Release a lock.

acquire(channel_number: int) → None[source]: Request a lock acquisition

release(channel_number: int) → None[source]: Release a lock.