Cryomagnetics Drivers

Exceptions:

Cryomagnetics4GException
Cryomagnetics4GWarning

Classes:

CryomagneticsModel4G(name, address, ...)	Driver for the Cryomagnetics Model 4G superconducting magnet power supply.
CryomagneticsOperatingState([ramping, ...])

exception qcodes.instrument_drivers.cryomagnetics.Cryomagnetics4GException

Bases: Exception

exception qcodes.instrument_drivers.cryomagnetics.Cryomagnetics4GWarning

Bases: Warning

class qcodes.instrument_drivers.cryomagnetics.CryomagneticsModel4G(name: str, address: str, max_current_limits: dict[int, tuple[float, float]], coil_constant: float, **kwargs: Unpack[VisaInstrumentKWArgs])

Bases: VisaInstrument

Driver for the Cryomagnetics Model 4G superconducting magnet power supply.

This driver provides an interface to control and communicate with the Cryomagnetics Model 4G superconducting magnet power supply using the VISA protocol. It allows setting and reading the magnetic field, ramp rate, and various other parameters of the instrument.

Parameters:

• name – The name of the instrument instance.

• address – The VISA resource name of the instrument.

• max_current_limits – A dictionary specifying the maximum current limits and rates for each range. The keys are the range indices, and the values are tuples containing the upper current limit and maximum rate for that range.

• coil_constant – The coil constant of the magnet in Tesla per Amp.

• **kwargs – Forwarded to base class.

Attributes:

KG_TO_TESLA
default_terminator	The default terminator to use if the terminator is not specified when creating the instrument.
units	Field Units
ramping_state_check_interval	Parameter ramping_state_check_interval
field	Magnetic Field in Tesla
rate	Rate for magnetic field T/min
Vmag	Magnet sense voltage
Vout	Magnet output voltage
Iout	Magnet output field/current

Methods:

quenched_state_reset()	Resets the device's quenched state.
operating_mode([remote])	Sets the device's operating mode to either remote or local.
zero_current()	Sets the device current to zero.
reset()	Resets the device to its default settings.
magnet_operating_state()	Retrieves the current operating state of the magnet.
set_field(field_setpoint[, block])	Sets the magnetic field strength in Tesla using ULIM, LLIM, and SWEEP commands.
wait_while_ramping(value[, threshold])	Waits while the magnet is ramping, checking the status byte instead of field value.
write_raw(cmd)	Low-level interface to visa_handle.write.
ask_raw(cmd)	Low-level interface to visa_handle.ask.

KG_TO_TESLA: float = 0.1

default_terminator: str | None = '\n'

The default terminator to use if the terminator is not specified when creating the instrument. None means use the default terminator from PyVisa.

units: Parameter = self.add_parameter( name="units", set_cmd="UNITS {}", get_cmd="UNITS?", get_parser=str, vals=Enum("A", "kG", "T"), docstring="Field Units", )

Field Units

ramping_state_check_interval: Parameter = self.add_parameter( "ramping_state_check_interval", initial_value=0.05, unit="s", vals=Numbers(0, 10), set_cmd=None, )

Parameter ramping_state_check_interval

field: Parameter = self.add_parameter( name="field", unit="T", set_cmd=self.set_field, get_cmd=self._get_field, get_parser=float, vals=Numbers(-9.001, 9.001), docstring="Magnetic Field in Tesla", )

Magnetic Field in Tesla

rate: Parameter = self.add_parameter( name="rate", unit="T/min", get_cmd=self._get_rate, set_cmd=self._set_rate, get_parser=float, docstring="Rate for magnetic field T/min", )

Rate for magnetic field T/min

Vmag: Parameter = self.add_parameter( name="Vmag", unit="V", get_cmd="VMAG?", get_parser=float, vals=Numbers(-10, 10), docstring="Magnet sense voltage", )

Magnet sense voltage

Vout: Parameter = self.add_parameter( name="Vout", unit="V", get_cmd="VOUT?", get_parser=float, vals=Numbers(-12.8, 12.8), docstring="Magnet output voltage", )

Magnet output voltage

Iout: Parameter = self.add_parameter( name="Iout", unit="A", get_cmd="IOUT?", get_parser=float, docstring="Magnet output field/current", )

Magnet output field/current

quenched_state_reset() → None

Resets the device’s quenched state.

operating_mode(remote: bool = True) → None

Sets the device’s operating mode to either remote or local.

Parameters:

remote – If True, sets to remote mode, otherwise sets to local mode.

zero_current() → None

Sets the device current to zero.

reset() → None

Resets the device to its default settings.

magnet_operating_state() → CryomagneticsOperatingState

Retrieves the current operating state of the magnet.

Returns:

An object representing the current operating state of the magnet.

Return type:

CryomagneticsOperatingState

Raises:

Cryomagnetics4GException – If the magnet is in a state that prevents ramping, such as quench condition, power module failure, or already ramping.

The operating state is determined by querying the status byte (*STB?) of the instrument. The status byte is interpreted as follows: - Bit 0: Holding (not ramping) - Bit 1: Ramping - Bit 2: Standby - Bit 4: Quench condition present - Bit 8: Power module failure

If the magnet is in a state that prevents ramping (quench condition, power module failure, or already ramping), an exception is raised with an appropriate error message. The error message is also logged using the instrument’s logger.

If the magnet is in a valid state for ramping, a CryomagneticsOperatingState object is returned, representing the current operating state of the magnet.

set_field(field_setpoint: float, block: bool = True) → None

Sets the magnetic field strength in Tesla using ULIM, LLIM, and SWEEP commands.

Parameters:

• field_setpoint – The desired magnetic field strength in Tesla.

• block – If True, the method will block until the field reaches the setpoint.

Raises:

Cryo4GException – If the power supply is not in a state where it can start ramping.

wait_while_ramping(value: float, threshold: float = 1e-05) → CryomagneticsOperatingState

Waits while the magnet is ramping, checking the status byte instead of field value.

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] = {}

write_raw(cmd: str) → None

Low-level interface to visa_handle.write.

Parameters:

cmd – The command to send to 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

class qcodes.instrument_drivers.cryomagnetics.CryomagneticsOperatingState(ramping: 'bool' = False, holding: 'bool' = False, standby: 'bool' = False, quench_condition_present: 'bool' = False, power_module_failure: 'bool' = False)

Bases: object

Attributes:

ramping
holding
standby
quench_condition_present
power_module_failure

Methods:

can_start_ramping()

ramping: bool = False

holding: bool = False

standby: bool = False

quench_condition_present: bool = False

power_module_failure: bool = False

can_start_ramping() → bool