from typing import Any, Dict, Optional, Tuple
from qcodes.instrument import Instrument
from qcodes.parameters import MultiParameter, Parameter, ParamRawDataType
from qcodes.validators import Bool, Enum
class CurrentParameter(MultiParameter):
"""
Voltage measurement via an Ithaco preamp and converting volt to current.
To be used when you feed a current into the Ithaco, send the Ithaco's
output voltage to a lockin or other voltage amplifier, and you have
the voltage reading from that amplifier as a qcodes parameter.
``CurrentParameter.get()`` returns ``(volt_raw, curr)``
Args:
measured_param: a gettable parameter returning the
voltage read from the Ithaco output.
c_amp_ins: an Ithaco instance where you manually
maintain the present settings of the real Ithaco amp.
Note: it should be possible to use other current preamps, if they
define parameters ``sens`` (sensitivity, in A/V), ``sens_factor``
(an additional gain) and ``invert`` (bool, output is inverted)
name: the name of the current output. Default 'curr'.
Also used as the name of the whole parameter.
"""
def __init__(self,
measured_param: Parameter,
c_amp_ins: "Ithaco_1211",
name: str = 'curr'):
p_name = measured_param.name
super().__init__(name=name,
names=(p_name+'_raw', name),
shapes=((), ()),
setpoints=((), ()),
instrument=c_amp_ins,
snapshot_value=True)
self._measured_param = measured_param
p_label = getattr(measured_param, "label", "")
p_unit = getattr(measured_param, "unit", "")
self.labels = (p_label, 'Current')
self.units = (p_unit, 'A')
def get_raw(self) -> Tuple[ParamRawDataType, ...]:
assert isinstance(self.instrument, Ithaco_1211)
volt = self._measured_param.get()
current = (self.instrument.sens.get() *
self.instrument.sens_factor.get()) * volt
if self.instrument.invert.get():
current *= -1
value = (volt, current)
return value
[docs]class Ithaco1211(Instrument):
"""
QCoDeS driver for the Ithaco 1211 Current-preamplifier.
This is a virtual driver only and will not talk to your instrument.
"""
def __init__(self, name: str, **kwargs: Any):
super().__init__(name, **kwargs)
self.add_parameter('sens',
initial_value=1e-8,
label='Sensitivity',
unit='A/V',
get_cmd=None, set_cmd=None,
vals=Enum(1e-11, 1e-10, 1e-09, 1e-08, 1e-07,
1e-06, 1e-05, 1e-4, 1e-3))
self.add_parameter('invert',
initial_value=True,
label='Inverted output',
get_cmd=None, set_cmd=None,
vals=Bool())
self.add_parameter('sens_factor',
initial_value=1,
label='Sensitivity factor',
unit=None,
get_cmd=None, set_cmd=None,
vals=Enum(0.1, 1, 10))
self.add_parameter('suppression',
initial_value=1e-7,
label='Suppression',
unit='A',
get_cmd=None, set_cmd=None,
vals=Enum(1e-10, 1e-09, 1e-08, 1e-07, 1e-06,
1e-05, 1e-4, 1e-3))
self.add_parameter('risetime',
initial_value=0.3,
label='Rise Time',
unit='msec',
get_cmd=None, set_cmd=None,
vals=Enum(0.01, 0.03, 0.1, 0.3, 1, 3, 10, 30,
100, 300, 1000))
[docs] def get_idn(self) -> Dict[str, Optional[str]]:
vendor = 'Ithaco (DL Instruments)'
model = '1211'
serial = None
firmware = None
return {'vendor': vendor, 'model': model,
'serial': serial, 'firmware': firmware}
class Ithaco_1211(Ithaco1211):
"""
Old alias for Itaco1211. Will eventually be deprecated and removed.
"""