qcodespp.instrument_drivers.cryogenic.CryogenicSMS120C

Attributes

Classes

Module Contents

qcodespp.instrument_drivers.cryogenic.CryogenicSMS120C.log

class qcodespp.instrument_drivers.cryogenic.CryogenicSMS120C.CryogenicSMS120C(name, address, coil_constant=0.113375, current_rating=105.84, current_ramp_limit=0.0506, reset=False, querytime=0.5, timeout=5, log_timeouts=False, terminator='\r\n', **kwargs)

Bases: qcodes.VisaInstrument

The following hard-coded, default values for Cryogenic magnets are safety limits and should not be modified. - these values should be set using the corresponding arguments when the class is called.

default_current_ramp_limit = 0.0506

default_max_current_ramp_limit = 0.12

Driver for the Cryogenic SMS120C magnet power supply. This class controls a single magnet PSU. Magnet and magnet PSU limits : max B=12T, I=105.84A, V=3.5V

Args:

name (string): a name for the instrument address (string): (serial to USB) COM number of the power supply coil_constant (float): coil constant in Tesla per ampere, fixed at 0.113375T/A current_rating (float): maximum current rating in ampere, fixed at 105.84A current_ramp_limit (float): current ramp limit in ampere per second,

for 50mK operation 0.0506A/s (5.737E-3 T/s, 0.34422T/min) - usually used for 4K operation 0.12A/s (0.013605 T/s, 0.8163 T/min) - not recommended

Note about timing : SMS120C needs a minimum of 200ms delay between commands being sent. The controller will send bad commands if asked too often. This driver tries to circumvent that. If the controller sends a bad command, the code will wait for the ‘timeout’ time (default 5s) before asking for the parameter again, and will keep asking until the controller sends something sensible. The problem mainly occurs when getting parameters. However, the problem is most prevalent when _setting_ the field, since the code has to continually/regularly ask the controller whether the field has been reached. To get around this, you can set an appropriate querytime>0.2s (default 0.5s). However this limits the sweeprate to at least this value. Alternatively, you can use one of the other rampModes (see description in parameter)

get_idn()

Overwrites the get_idn function using constants as the hardware does not have a proper *IDN function.

query(msg)

Message outputs do not follow the standard SCPI format, separate regexp to parse unique/variable instrument message structures.

Returns:

key : unused value : parsed value extracted from output message