agilent.py

#!/usr/bin/env python

from __future__ import absolute_import
import logging
import visa
from visa_probestation_dev import VisaProbestationDev

class AgilentMeter ( VisaProbestationDev ) :
	def __init__ ( self, resource_name, useserial ) :
		super ( AgilentMeter, self ) .__init__ ( resource_name, useserial )

		self._write ( u"*RST; *CLS" )
		self._write ( u":FORMAT:ASCII:LONG ON" )

	def identify ( self ) :
		return self._query ( u"*IDN?" ) .strip ( )

class AgilentE4980A ( AgilentMeter ) :
	def __init__ ( self, resource_name, useserial ) :
		super (AgilentE4980A, self ) .__init__ ( resource_name, useserial )

		# might need something else for resistance
		self._write ( u":FUNCTION:IMPEDANCE CPG" )
		self._write ( u":APER MED,5" )

	def get_VDC ( self ) :
		return self._query ( u":FETCH:SMONITOR:VDC?" )

	def get_voltage_level ( self ) :
		return self._query ( u":VOLTAGE?" )

	def set_voltage_level ( self, volts ) :
		if not 0 <= volts <= 20 :
			raise ValueError ( u"Voltage level out of range [0;20]: {}" .format ( volts ) )

		self._write ( u":VOLTAGE {}" .format ( volts ) )

	def get_frequency ( self ) :
		return self._query ( u":FREQUENCY?" )

	def set_frequency ( self, freq ) :
		if not 20 <= freq <= 2e6 :
			raise ValueError ( u"Frequency out of range [0;2e6]: {}" .format ( freq ) )

		self._write ( u":FREQUENCY {}" .format ( freq ) )

	def get_reading ( self ) :
		return self._query ( u"FETCH?" ) .strip ( )

	def get_resistance ( self ) :
		self._write ( u":FUNCTION:IMPEDANCE RX" )
		resi = self._query ( u":FETCH:IMPEDANCE:CORRECTED?" )
		return resi

def parse_cgv ( line, devname ) :
	line = line.split ( u"," )
	ret = {}
	ret[u"{}_capacitance" .format ( devname ) ] = float ( line[0] )
	ret[u"{}_conductance" .format ( devname ) ] = float ( line[1] )
	return ret

def parse_res ( line, devname ) :
	line = line.split ( u"," )
	ret = {}
	ret[u"{}_resistance" .format ( devname ) ] = float ( line[0] )
	ret[u"{}_impedance" .format ( devname ) ] = float ( line[1] )
	return ret

if __name__ == u"__main__" :
	a = AgilentE4980A ( u"GPIB0::20::INSTR", False )