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from qolab.hardware.basic import BasicInstrument
from qolab.hardware.multimeter import MultimeterSCPI
from qolab.hardware.scpi import SCPI_PROPERTY
from pyvisa import constants as pyvisa_constants
import time
class HP_34401(MultimeterSCPI):
r"""HP 34401 multimeter (same as Agilent 34401)
Example
-------
>>> from qolab.hardware.multimeter.hp_34401 import HP_34401
>>> rm = pyvisa.ResourceManager()
>>> instr=rm.open_resource('ASRL/dev/ttyUSB0::INSTR')
>>> multimeter = HP_34401(instr)
>>> print("------ Header start -------------")
>>> print(str.join("\n", multimeter.getHeader()))
>>> print("------ Header ends -------------")
"""
def __init__(self, resource, *args, **kwds):
super().__init__(resource, *args, **kwds)
self.config["Device model"] = "HP 34401"
self.resource.read_termination = "\r\n"
self.resource.baud_rate = 9600
self.resource.data_bits = 8
self.resource.parity = pyvisa_constants.Parity.none
self.resource.stop_bits = pyvisa_constants.StopBits.one
self.resource.timeout = 5000
self.switchTime = 0.5 # switch time in seconds for Function/Measurement change
self.deviceProperties.update({"Function"})
rawFunction = SCPI_PROPERTY(
scpi_prfx="SENSe:FUNCtion",
ptype=str,
doc="""
Current measurement function (Voltmeter DC/AC, Currentmeter DC/AC, etc.
Important! When assigning, string should be quoted, i.e. use:
Function=\'"VOLT:DC"\'
Possible values:
"VOLTage:DC", same as "VOLT"
"VOLTage:DC:RATio"
"VOLTage:AC"
"CURRent:DC", same as "CURR"
"CURRent:AC"
"RESistance" (2-wire ohms)
"FRESistance" (4-wire ohms)
"FREQuency"
"PERiod"
"CONTinuity"
"DIODe"
""",
)
def getFunction(self):
rfunc = self.rawFunction
if rfunc == '"VOLT"':
return "Vdc"
elif rfunc == '"VOLT:AC"':
return "Vac"
elif rfunc == '"CURR"':
return "Adc"
elif rfunc == '"CURR:AC"':
return "Aac"
elif rfunc == '"RES"':
return "Resistance"
elif rfunc == '"FRES"':
return "Resistance4Wires"
elif rfunc == '"DIOD"':
return "Diode"
elif rfunc == '"FREQ"':
return "Frequency"
elif rfunc == '"PER"':
return "Period"
elif rfunc == '"CONT"':
return "Continuity"
else:
return "Unknown"
def toRemote(self):
self.write("SYSTem:REMote")
def toLocal(self):
self.write("SYSTem:LOCal")
def isSensing(self, test):
return test == self.rawFunction
Reading = SCPI_PROPERTY(
scpi_prfx="SYSTem:REMote; :READ",
ptype=float,
doc="Report current measurement",
no_setter=True,
)
# HP 34401 is tricky
# when reading over serial interface the value of measurement/function,
# the device need to be switched to REMOTE mode, but this leaves screen blank and unusable
# so we have to do the dance with toRemote and toLocal
def getReadingWithSettingFunction(
self, desired_function_string, function_internal_name
):
"""
Get the required reading.
But first check if the multimeter is set to do specific function/measurement.
If the instrument set to do different function, set to the desired one.
Note: the function name should be in quotes, i.e. "Volt".
"""
if not self.isSensing(function_internal_name):
self.rawFunction = desired_function_string
time.sleep(self.switchTime)
# self.toRemote() # this is done inside of Reading
ret = self.Reading
self.toLocal()
return ret
@BasicInstrument.tsdb_append
def getVdc(self):
return self.getReadingWithSettingFunction('"VOLTage:DC"', '"VOLT"')
@BasicInstrument.tsdb_append
def getVac(self):
return self.getReadingWithSettingFunction('"VOLTage:AC"', '"VOLT:AC"')
@BasicInstrument.tsdb_append
def getAdc(self):
return self.getReadingWithSettingFunction('"CURRent:DC"', '"CURR"')
@BasicInstrument.tsdb_append
def getAac(self):
return self.getReadingWithSettingFunction('"CURRent:AC"', '"CURR:AC"')
@BasicInstrument.tsdb_append
def getResistance(self):
return self.getReadingWithSettingFunction('"RESistance"', '"RES"')
@BasicInstrument.tsdb_append
def getResistance4Wires(self):
return self.getReadingWithSettingFunction('"FRESistance"', '"FRES"')
@BasicInstrument.tsdb_append
def getDiode(self):
return self.getReadingWithSettingFunction('"DIODe"', '"DIOD"')
@BasicInstrument.tsdb_append
def getFreq(self):
return self.getReadingWithSettingFunction('"FREQuency"', '"FREQ"')
@BasicInstrument.tsdb_append
def getPeriod(self):
return self.getReadingWithSettingFunction('"PERiod"', '"PER"')
if __name__ == "__main__":
import pyvisa
print("testing")
rm = pyvisa.ResourceManager()
print(rm.list_resources())
instr = rm.open_resource("ASRL/dev/ttyUSB0::INSTR")
multimeter = HP_34401(instr)
print("------ Header start -------------")
print(str.join("\n", multimeter.getHeader()))
print("------ Header ends -------------")
|
