Lakeshore Drivers

Classes:

LakeshoreModel325(name, address, **kwargs)

QCoDeS driver for Lakeshore Model 325 Temperature Controller.

LakeshoreModel325Curve(parent, index)

An InstrumentChannel representing a curve on a Lakeshore Model 325

LakeshoreModel325Heater(parent, name, loop)

InstrumentChannel for heater control on a Lakeshore Model 325.

LakeshoreModel325Sensor(parent, name, inp)

InstrumentChannel for a single sensor of a Lakeshore Model 325.

LakeshoreModel325Status(value[, names, ...])

IntFlag that defines status codes for Lakeshore Model 325

LakeshoreModel335(name, address, **kwargs)

Lakeshore Model 335 Temperature Controller Driver

LakeshoreModel335Channel(parent, name, channel)

An InstrumentChannel representing a single sensor on a Lakeshore Model 335.

LakeshoreModel335CurrentSource(parent, ...)

InstrumentChannel for current sources on Lakeshore Model 335.

LakeshoreModel336(name, address, **kwargs)

QCoDeS driver for Lakeshore Model 336 Temperature Controller.

LakeshoreModel336Channel(parent, name, channel)

An InstrumentChannel representing a single sensor on a Lakeshore Model 336.

LakeshoreModel336CurrentSource(parent, ...)

InstrumentChannel for current sources on Lakeshore Model 336.

LakeshoreModel336VoltageSource(parent, ...)

InstrumentChannel for voltage sources on Lakeshore Model 336.

LakeshoreModel372(name, address, **kwargs)

QCoDeS driver for Lakeshore Model 372 Temperature Controller.

LakeshoreModel372Channel(parent, name, channel)

An InstrumentChannel representing a single sensor on a Lakeshore Model 372.

LakeshoreModel372Output(parent, output_name, ...)

An InstrumentChannel for control outputs (heaters) of Lakeshore Model 372

class qcodes.instrument_drivers.Lakeshore.LakeshoreModel325(name: str, address: str, **kwargs: Any)[source]

Bases: VisaInstrument

QCoDeS driver for Lakeshore Model 325 Temperature Controller.

Methods:

upload_curve(index, name, serial_number, ...)

Upload a curve to the given index

upload_curve_from_file(index, file_path)

Upload a curve from a curve file.

__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().

upload_curve(index: int, name: str, serial_number: str, data_dict: dict[Any, Any]) None[source]

Upload a curve to the given index

Parameters:
  • index – The index to upload the curve to. We can only use indices reserved for user defined curves, 21-35

  • name

  • serial_number

  • data_dict – A dictionary containing the curve data

upload_curve_from_file(index: int, file_path: str) None[source]

Upload a curve from a curve file. Note that we only support curve files with extension .330

__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_timetime.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:

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.Lakeshore.LakeshoreModel325Curve(parent: LakeshoreModel325, index: int)[source]

Bases: InstrumentChannel

An InstrumentChannel representing a curve on a Lakeshore Model 325

Attributes:

valid_sensor_units

temperature_key

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_data()

validate_datadict(data_dict)

A data dict has two keys, one of which is 'Temperature (K)'.

set_data(data_dict[, sensor_unit])

Set the curve data according to the values found the the dictionary.

__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)

valid_sensor_units = ('mV', 'V', 'Ohm', 'log Ohm')
temperature_key = 'Temperature (K)'
get_data() dict[Any, Any][source]
classmethod validate_datadict(data_dict: dict[Any, Any]) str[source]

A data dict has two keys, one of which is ‘Temperature (K)’. The other contains the units in which the curve is defined and must be one of: ‘mV’, ‘V’, ‘Ohm’ or ‘log Ohm’

This method validates this and returns the sensor unit encountered in the data dict

set_data(data_dict: dict[Any, Any], sensor_unit: str | None = None) None[source]

Set the curve data according to the values found the the dictionary.

Parameters:
  • data_dict (dict) – See validate_datadict to see the format of this dictionary

  • sensor_unit (str) – If None, the data dict is validated and the units are extracted.

__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:

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.Lakeshore.LakeshoreModel325Heater(parent: LakeshoreModel325, name: str, loop: int)[source]

Bases: InstrumentChannel

InstrumentChannel for heater control on a Lakeshore Model 325.

Parameters:

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)

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.

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().

__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:

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.Lakeshore.LakeshoreModel325Sensor(parent: LakeshoreModel325, name: str, inp: str)[source]

Bases: InstrumentChannel

InstrumentChannel for a single sensor of a Lakeshore Model 325.

Parameters:
  • parent (LakeshoreModel325) – The instrument this heater belongs to

  • name (str) –

  • inp (str) – Either “A” or “B”

Methods:

decode_sensor_status(sum_of_codes)

__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)

Attributes:

curve

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().

static decode_sensor_status(sum_of_codes: int) str[source]
property curve: LakeshoreModel325Curve
__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:

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.Lakeshore.LakeshoreModel325Status(value, names=None, *, module=None, qualname=None, type=None, start=1, boundary=None)[source]

Bases: IntFlag

IntFlag that defines status codes for Lakeshore Model 325

Attributes:

sensor_units_overrang

sensor_units_zero

temp_overrange

temp_underrange

invalid_reading

denominator

the denominator of a rational number in lowest terms

imag

the imaginary part of a complex number

numerator

the numerator of a rational number in lowest terms

real

the real part of a complex number

Methods:

__contains__(other)

Returns True if self has at least the same flags set as other.

__dir__()

Returns public methods and other interesting attributes.

__getitem__(name)

Return the member matching name.

__iter__()

Returns flags in definition order.

as_integer_ratio()

Return integer ratio.

bit_count()

Number of ones in the binary representation of the absolute value of self.

bit_length()

Number of bits necessary to represent self in binary.

conjugate

Returns self, the complex conjugate of any int.

from_bytes([byteorder, signed])

Return the integer represented by the given array of bytes.

to_bytes([length, byteorder, signed])

Return an array of bytes representing an integer.

sensor_units_overrang = 128
sensor_units_zero = 64
temp_overrange = 32
temp_underrange = 16
invalid_reading = 1
__contains__(other)

Returns True if self has at least the same flags set as other.

__dir__()

Returns public methods and other interesting attributes.

classmethod __getitem__(name)

Return the member matching name.

__iter__()

Returns flags in definition order.

as_integer_ratio()

Return integer ratio.

Return a pair of integers, whose ratio is exactly equal to the original int and with a positive denominator.

>>> (10).as_integer_ratio()
(10, 1)
>>> (-10).as_integer_ratio()
(-10, 1)
>>> (0).as_integer_ratio()
(0, 1)
bit_count()

Number of ones in the binary representation of the absolute value of self.

Also known as the population count.

>>> bin(13)
'0b1101'
>>> (13).bit_count()
3
bit_length()

Number of bits necessary to represent self in binary.

>>> bin(37)
'0b100101'
>>> (37).bit_length()
6
conjugate()

Returns self, the complex conjugate of any int.

denominator

the denominator of a rational number in lowest terms

from_bytes(byteorder='big', *, signed=False)

Return the integer represented by the given array of bytes.

bytes

Holds the array of bytes to convert. The argument must either support the buffer protocol or be an iterable object producing bytes. Bytes and bytearray are examples of built-in objects that support the buffer protocol.

byteorder

The byte order used to represent the integer. If byteorder is ‘big’, the most significant byte is at the beginning of the byte array. If byteorder is ‘little’, the most significant byte is at the end of the byte array. To request the native byte order of the host system, use `sys.byteorder’ as the byte order value. Default is to use ‘big’.

signed

Indicates whether two’s complement is used to represent the integer.

imag

the imaginary part of a complex number

numerator

the numerator of a rational number in lowest terms

real

the real part of a complex number

to_bytes(length=1, byteorder='big', *, signed=False)

Return an array of bytes representing an integer.

length

Length of bytes object to use. An OverflowError is raised if the integer is not representable with the given number of bytes. Default is length 1.

byteorder

The byte order used to represent the integer. If byteorder is ‘big’, the most significant byte is at the beginning of the byte array. If byteorder is ‘little’, the most significant byte is at the end of the byte array. To request the native byte order of the host system, use `sys.byteorder’ as the byte order value. Default is to use ‘big’.

signed

Determines whether two’s complement is used to represent the integer. If signed is False and a negative integer is given, an OverflowError is raised.

class qcodes.instrument_drivers.Lakeshore.LakeshoreModel335(name: str, address: str, **kwargs: Any)[source]

Bases: LakeshoreBase

Lakeshore Model 335 Temperature Controller Driver

Attributes:

channel_name_command

input_channel_parameter_values_to_channel_name_on_instrument

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().

Classes:

CHANNEL_CLASS

alias of LakeshoreModel335Channel

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)

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.

channel_name_command: ClassVar[dict[str, str]] = {'A': 'A', 'B': 'B'}
CHANNEL_CLASS

alias of LakeshoreModel335Channel Attributes:

SENSOR_STATUSES

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)

input_channel_parameter_values_to_channel_name_on_instrument: ClassVar[dict[Any, str]] = {'A': 'A', 'B': 'B'}
__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_timetime.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:

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.Lakeshore.LakeshoreModel335Channel(parent: LakeshoreModel335, name: str, channel: str)[source]

Bases: BaseSensorChannel

An InstrumentChannel representing a single sensor on a Lakeshore Model 335.

Attributes:

SENSOR_STATUSES

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().

log

metadata

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)

SENSOR_STATUSES: ClassVar[dict[int, str]] = {0: 'OK', 1: 'Invalid Reading', 16: 'Temp Underrange', 32: 'Temp Overrange', 64: 'Sensor Units Zero', 128: 'Sensor Units Overrange'}
__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:

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.Lakeshore.LakeshoreModel335CurrentSource(parent: LakeshoreModel335, output_name: str, output_index: int)[source]

Bases: BaseOutput

InstrumentChannel for current sources on Lakeshore Model 335.

Class for control outputs 1 and 2 of Lakeshore Model 335 that are variable DC current sources referenced to chassis ground.

Attributes:

MODES

RANGES

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.

set_range_from_temperature(temperature)

Sets the output range of this given heater from a given temperature.

set_setpoint_and_range(temperature)

Sets the range from the given temperature, and then sets the setpoint to this given temperature.

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

wait_until_set_point_reached([...])

This function runs a loop that monitors the value of the heater's input channel until the read values is close to the setpoint value that has been set before.

write(cmd)

write_raw(cmd)

MODES: ClassVar[dict[str, int]] = {'closed_loop': 1, 'off': 0, 'open_loop': 3, 'zone': 2}
RANGES: ClassVar[dict[str, int]] = {'high': 3, 'low': 1, 'medium': 2, 'off': 0}
__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:

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.

set_range_from_temperature(temperature: float) str

Sets the output range of this given heater from a given temperature.

The output range is determined by the limits given through the parameter range_limits. The output range is used for temperatures between the limits range_limits[i-1] and range_limits[i]; that is range_limits is the upper limit for using a certain heater current.

Parameters:

temperature – temperature to set the range from

Returns:

the value of the resulting output_range, that is also available from the output_range parameter itself

set_setpoint_and_range(temperature: float) None

Sets the range from the given temperature, and then sets the setpoint to this given temperature.

Note that the preferred units of the heater output are expected to be kelvin.

Parameters:

temperature – temperature in K

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.

wait_until_set_point_reached(wait_cycle_time: float | None = None, wait_tolerance: float | None = None, wait_equilibration_time: float | None = None) None

This function runs a loop that monitors the value of the heater’s input channel until the read values is close to the setpoint value that has been set before.

Note that if the setpoint value is in a different range, this function may wait forever because that setpoint cannot be reached within the current range.

Parameters:
  • wait_cycle_time – this time is being waited between the readings (same as wait_cycle_time parameter); if None, then the value of the corresponding wait_cycle_time parameter is used

  • wait_tolerance – this value is used to determine if the reading value is close enough to the setpoint value according to the following formula: abs(t_reading - t_setpoint)/t_reading < wait_tolerance (same as wait_tolerance parameter); if None, then the value of the corresponding wait_tolerance parameter is used

  • wait_equilibration_time – within this time, the reading value has to stay within the defined tolerance in order for this function to return (same as wait_equilibration_time parameter); if None, then the value of the corresponding wait_equilibration_time parameter is used

write(cmd: str) None
write_raw(cmd: str) None
INVERSE_RANGES: dict[int, str] = {v: k for k, v in self.RANGES.items()}
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.Lakeshore.LakeshoreModel336(name: str, address: str, **kwargs: Any)[source]

Bases: LakeshoreBase

QCoDeS driver for Lakeshore Model 336 Temperature Controller.

Attributes:

channel_name_command

input_channel_parameter_values_to_channel_name_on_instrument

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().

Classes:

CHANNEL_CLASS

alias of LakeshoreModel336Channel

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)

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.

channel_name_command: ClassVar[dict[str, str]] = {'A': 'A', 'B': 'B', 'C': 'C', 'D': 'D'}
CHANNEL_CLASS

alias of LakeshoreModel336Channel Attributes:

SENSOR_STATUSES

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)

input_channel_parameter_values_to_channel_name_on_instrument: ClassVar[dict[Any, str]] = {'A': 'A', 'B': 'B', 'C': 'C', 'D': 'D'}
__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_timetime.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:

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.Lakeshore.LakeshoreModel336Channel(parent: LakeshoreModel336, name: str, channel: str)[source]

Bases: BaseSensorChannel

An InstrumentChannel representing a single sensor on a Lakeshore Model 336.

Attributes:

SENSOR_STATUSES

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().

log

metadata

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.