QDev Drivers

Classes:

QDevQDac(name, address[, num_chans, ...])	Channelised driver for the QDev digital-analog converter QDac
QDevQDacChannel(parent, name, channum, **kwargs)	A single output channel of the QDac.

class qcodes.instrument_drivers.QDev.QDevQDac(name: str, address: str, num_chans: int = 48, update_currents: bool = True, **kwargs: Unpack[VisaInstrumentKWArgs])

Bases: VisaInstrument

Channelised driver for the QDev digital-analog converter QDac

Based on “DAC_commands_v_13.pdf” Tested with Software Version: 0.170202

The driver assumes that the instrument is ALWAYS in verbose mode OFF

Instantiates the instrument.

Parameters:

• name – The instrument name used by qcodes

• address – The VISA name of the resource

• num_chans – Number of channels to assign. Default: 48

• update_currents – Whether to query all channels for their current current value on startup. Default: True.

• **kwargs – kwargs are forwarded to base class.

Returns:

QDac object

Attributes:

max_status_age
cal	Parameter cal
verbose	Parameter verbose

Methods:

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).
printslopes()	Print the finite slopes assigned to channels
write(cmd)	QDac always returns something even from set commands, even when verbose mode is off, so we'll override write to take this out if you want to use this response, we put it in self._write_response (but only for the very last write call)
read()
connect_message([idn_param, begin_time])	Override of the standard Instrument class connect_message.
print_overview([update_currents])	Pretty-prints the status of the QDac

max_status_age = 1

cal: Parameter = self.add_parameter( name="cal", set_cmd="cal {}", vals=self.channel_validator )

Parameter cal

verbose: Parameter = self.add_parameter( name="verbose", set_cmd="ver {}", val_mapping={True: 1, False: 0} )

Parameter verbose

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 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

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] = {}

printslopes() → None

Print the finite slopes assigned to channels

write(cmd: str) → None

QDac always returns something even from set commands, even when verbose mode is off, so we’ll override write to take this out if you want to use this response, we put it in self._write_response (but only for the very last write call)

In this method we expect to read one termination char per command. As commands are concatenated by ; we count the number of concatenated commands as count(‘;’) + 1 e.g. ‘wav 1 1 1 0;fun 2 1 100 1 1’ is two commands. Note that only the response of the last command will be available in _write_response

read() → str

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

Override of the standard Instrument class connect_message. Usually, the response to *IDN? is printed. Here, the software version is printed.

print_overview(update_currents: bool = False) → None

Pretty-prints the status of the QDac

class qcodes.instrument_drivers.QDev.QDevQDacChannel(parent: Instrument, name: str, channum: int, **kwargs: Unpack[InstrumentBaseKWArgs])

Bases: InstrumentChannel

A single output channel of the QDac.

Exposes chan.v, chan.vrange, chan.slope, chan.i, chan.irange

Parameters:

• parent – The instrument to which the channel is attached.

• name – The name of the channel

• channum – The number of the channel in question (1-48)

• **kwargs – Forwarded to base class.

Attributes:

v	Parameter v
vrange	Parameter vrange
i	Parameter i
irange	Parameter irange
slope	Parameter slope
sync	Parameter sync
sync_delay	Parameter sync_delay
sync_duration	Parameter sync_duration

Methods:

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).

v: Parameter = self.add_parameter( "v", label=f"Channel {channum} voltage", unit="V", set_cmd=partial(self._parent._set_voltage, channum), get_cmd=partial(self._parent._get_voltage, channum), get_parser=float, vals=vals.Numbers(-10, 10), )

Parameter v

vrange: Parameter = self.add_parameter( "vrange", label=f"Channel {channum} atten.", set_cmd=partial(self._parent._set_vrange, channum), get_cmd=partial(self._parent._get_vrange, channum), vals=vals.Enum(0, 1), )

Parameter vrange

i: Parameter = self.add_parameter( "i", label=f"Channel {channum} current", get_cmd=f"get {channum}", unit="A", get_parser=self._parent._current_parser, )

Parameter i

irange: Parameter = self.add_parameter( "irange", label=f"Channel {channum} irange", set_cmd=f"cur {channum} {{}}", get_cmd=f"cur {channum}", get_parser=int, )

Parameter irange

slope: Parameter = self.add_parameter( "slope", label=f"Channel {channum} slope", unit="V/s", set_cmd=partial(self._parent._setslope, channum), get_cmd=partial(self._parent._getslope, channum), vals=vals.MultiType(vals.Enum("Inf"), vals.Numbers(1e-3, 100)), )

Parameter slope

sync: Parameter = self.add_parameter( "sync", label=f"Channel {channum} sync output", set_cmd=partial(self._parent._setsync, channum), get_cmd=partial(self._parent._getsync, channum), vals=vals.Ints(0, 5), )

Parameter sync

sync_delay: Parameter = self.add_parameter( name="sync_delay", label=f"Channel {channum} sync pulse delay", unit="s", get_cmd=None, set_cmd=None, initial_value=0, )

Parameter sync_delay

sync_duration: Parameter = self.add_parameter( name="sync_duration", label=f"Channel {channum} sync pulse duration", unit="s", get_cmd=None, set_cmd=None, initial_value=0.01, )

Parameter sync_duration

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

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] = {}