feat: Add basic driver for Keithley 2400 (#488)

clean-up of PR #235. I suspect buggy behaviour but have not tested the driver.

qcodes/instrument_drivers/tektronix/Keithley_2400.py

@@ -0,0 +1,118 @@
+from qcodes import VisaInstrument
+from qcodes.utils.validators import Strings, Enum
+
+
+class Keithley_2400(VisaInstrument):
+    """
+    QCoDeS driver for the Keithley 2400 voltage source.
+    """
+    def __init__(self, name, address, **kwargs):
+        super().__init__(name, address, terminator='\n', **kwargs)
+
+        self.add_parameter('rangev',
+                           get_cmd='SENS:VOLT:RANG?',
+                           get_parser=float,
+                           set_cmd='SOUR:VOLT:RANG {:f}',
+                           label='Voltage range')
+
+        self.add_parameter('rangei',
+                           get_cmd='SENS:CURR:RANG?',
+                           get_parser=float,
+                           set_cmd='SOUR:CURR:RANG {:f}',
+                           label='Current range')
+
+        self.add_parameter('compliancev',
+                           get_cmd='SENS:VOLT:PROT?',
+                           get_parser=float,
+                           set_cmd='SENS:VOLT:PROT {:f}',
+                           label='Voltage Compliance')
+
+        self.add_parameter('compliancei',
+                           get_cmd='SENS:CURR:PROT?',
+                           get_parser=float,
+                           set_cmd='SENS:CURR:PROT {:f}',
+                           label='Current Compliance')
+
+        self.add_parameter('volt',
+                           get_cmd=':READ?',
+                           get_parser=self._volt_parser,
+                           set_cmd=':SOUR:VOLT:LEV {:.8f}',
+                           label='Voltage',
+                           unit='V')
+
+        self.add_parameter('curr',
+                           get_cmd=':READ?',
+                           get_parser=self._curr_parser,
+                           set_cmd=':SOUR:CURR:LEV {:.8f}',
+                           label='Current',
+                           unit='A')
+
+        self.add_parameter('mode',
+                           vals=Enum('VOLT', 'CURR'),
+                           get_cmd=':SOUR:FUNC?',
+                           set_cmd=self._set_mode_and_sense,
+                           label='Mode')
+
+        self.add_parameter('sense',
+                           vals=Strings(),
+                           get_cmd=':SENS:FUNC?',
+                           set_cmd=':SENS:FUNC "{:s}"',
+                           label='Sense mode')
+
+        self.add_parameter('output',
+                           get_parser=int,
+                           set_cmd=':OUTP:STAT {:d}',
+                           get_cmd=':OUTP:STAT?')
+
+        self.add_parameter('nplcv',
+                           get_cmd='SENS:VOLT:NPLC?',
+                           get_parser=float,
+                           set_cmd='SENS:VOLT:NPLC {:f}',
+                           label='Voltage integration time')
+
+        self.add_parameter('nplci',
+                           get_cmd='SENS:CURR:NPLC?',
+                           get_parser=float,
+                           set_cmd='SENS:CURR:NPLC {:f}',
+                           label='Current integration time')
+
+        self.add_parameter('resistance',
+                           get_cmd=':READ?',
+                           get_parser=self._resistance_parser,
+                           label='Resistance',
+                           units='Ohm')
+
+    def _set_mode_and_sense(self, msg):
+        # This helps set the correct read out curr/volt
+        if msg == 'VOLT':
+            self.sense('CURR')
+        elif msg == 'CURR':
+            self.sense('VOLT')
+        else:
+            raise AttributeError('Mode does not exist')
+        self.write(':SOUR:FUNC {:s}'.format(msg))
+
+    def reset(self):
+        """
+        Reset the instrument. When the instrument is reset, it performs the
+        following actions.
+
+            Returns the SourceMeter to the GPIB default conditions.
+
+            Cancels all pending commands.
+
+            Cancels all previously send '*OPC' and '*OPC?'
+        """
+        self.write(':*RST')
+
+    def _volt_parser(self, msg):
+        fields = [float(x) for x in msg.split(',')]
+        return fields[0]
+
+    def _curr_parser(self, msg):
+        fields = [float(x) for x in msg.split(',')]
+        return fields[1]
+
+    def _resistance_parser(self, msg):
+        fields = [float(x) for x in msg.split(',')]
+        return fields[0]/fields[1]