Port to PyVISA (deprecating scpi.py)

Author: robertjensen

PyExpLabSys/drivers/keithley_2182.py

@@ -1,55 +1,53 @@
 """ Simple driver for Keithley 2182 Nanovolt Meter """
 import time
-from PyExpLabSys.drivers.scpi import SCPI
 
+import pyvisa
 
-class Keithley2182(SCPI):
+
+class Keithley2182:
     """
     Simple driver for Keithley 2182 Nanovolt Meter
     Actual implementation performed on a 2182a - please
     double check if you have a 2182.
     """
 
-    def __init__(
-        self, interface, hostname='', device='', baudrate=9600, gpib_address=None
-    ):
-        self.interface = interface
-
+    def __init__(self, interface, hostname='', device='', baudrate=19200):
+        rm = pyvisa.ResourceManager('@py')
         if interface == 'serial':
-            SCPI.__init__(self, interface=interface, device=device, baudrate=baudrate)
-            self.comm_dev.timeout = 2
-            self.comm_dev.rtscts = False
-            self.comm_dev.xonxoff = False
-        if interface == 'gpib':
-            SCPI.__init__(self, interface=interface, gpib_address=gpib_address)
-
+            conn_string = 'ASRL{}::INSTR'.format(device)
+            self.instr = rm.open_resource(conn_string)
+            self.instr.read_termination = '\r'
+            self.instr.write_termination = '\r'
+            self.instr.baud_rate = baudrate
         # For now, turn off continous trigger - this might need reconsideration
         # self.scpi_comm('INIT:CONT OFF')
 
     def set_range(self, channel1: float = None, channel2: float = None):
         """
         Set the measurement range of the device, 0 will indicate auto-range
         """
+        print('Set range of channel 1')
         if channel1 is not None:
             if channel1 > 120:
                 channel1 = 120
             if channel1 == 0:
-                self.scpi_comm(':SENSE:VOLT:CHANNEL1:RANGE:AUTO ON')
+                self.instr.write(':SENSE:VOLT:CHANNEL1:RANGE:AUTO ON')
             else:
-                self.scpi_comm(':SENSE:VOLT:CHANNEL1:RANGE {:.2f}'.format(channel1))
+                self.instr.write(':SENSE:VOLT:CHANNEL1:RANGE {:.2f}'.format(channel1))
 
         if channel2 is not None:
             if channel2 > 12:
                 channel2 = 12
             if channel2 == 0:
-                self.scpi_comm(':SENSE:VOLTAGE:CHANNEL2:RANGE:AUTO ON')
+                self.instr.write(':SENSE:VOLTAGE:CHANNEL2:RANGE:AUTO ON')
             else:
-                self.scpi_comm(':SENSE:VOLT:CHANNEL2:RANGE {:.2f}'.format(channel2))
-
-        actual_channel1_raw = self.scpi_comm(':SENSE:VOLTAGE:CHANNEL1:RANGE?')
-        actual_channel2_raw = self.scpi_comm(':SENSE:VOLTAGE:CHANNEL2:RANGE?')
+                self.instr.write(':SENSE:VOLT:CHANNEL2:RANGE {:.2f}'.format(channel2))
+        print('Check the actual range')
+        actual_channel1_raw = self.instr.query(':SENSE:VOLTAGE:CHANNEL1:RANGE?')
+        actual_channel2_raw = self.instr.query(':SENSE:VOLTAGE:CHANNEL2:RANGE?')
         range1 = float(actual_channel1_raw)
         range2 = float(actual_channel2_raw)
+        print('Value is: ', range1)
         return range1, range2
 
     def set_integration_time(self, nplc: float = None):
@@ -61,9 +59,11 @@ def set_integration_time(self, nplc: float = None):
                 nplc = 0.01
             if nplc > 60:
                 nplc = 60
-            self.scpi_comm('SENSE:VOLTAGE:NPLCYCLES {}'.format(nplc))
-            time.sleep(nplc * 0.2)
-        current_nplc = float(self.scpi_comm('SENSE:VOLTAGE:NPLCYCLES?'))
+            self.instr.write('SENSE:VOLTAGE:NPLCYCLES {}'.format(nplc))
+            # print('waiting....')
+            time.sleep(nplc * 0.25)
+            # print('done')
+        current_nplc = float(self.instr.query('SENSE:VOLTAGE:NPLCYCLES?'))
         return current_nplc
 
     def set_trigger_source(self, external):
@@ -73,17 +73,17 @@ def set_trigger_source(self, external):
         otherwise immediate triggering will be chosen.
         """
         if external:
-            self.scpi_comm(':TRIGGER:SOURCE External')
+            self.instr.write(':TRIGGER:SOURCE External')
         else:
-            self.scpi_comm(':TRIGGER:SOURCE Immediate')
+            self.instr.write(':TRIGGER:SOURCE Immediate')
         return external
 
     def read_fresh(self):
         """
         Read a single value from current channel. This will also be a new value
         (or will fail if channel is not trigged.
         """
-        raw = self.scpi_comm(":DATA:FRESh?")  # DF? also works
+        raw = self.instr.query(':DATA:FRESh?')  # DF? also works
         try:
             voltage = float(raw)
         except ValueError:
@@ -94,29 +94,26 @@ def read_voltage(self, channel: int):
         """Read the measured voltage"""
         if channel not in (1, 2):
             return None
-        self.scpi_comm(":SENSE:FUNC 'VOLT:DC'")
-        self.scpi_comm(':SENSE:CHANNEL {}'.format(channel))
-        raw = self.scpi_comm(':READ?')
+        self.instr.write(":SENSE:FUNC 'VOLT:DC'")
+        time.sleep(0.5)
+        self.instr.write(':SENSE:CHANNEL {}'.format(channel))
+        time.sleep(0.5)
+        # raw = self.instr.query(':READ?')
+        raw = self.read_fresh()
         voltage = float(raw)
         return voltage
 
 
 if __name__ == '__main__':
-    GPIB = 7
+    # usb-1a86_USB2.0-Ser_-if00-port0 # Vxx
+    # usb-FTDI_Chipi-X_FT6EYK1T-if00-port0 #  DMM
+    # usb-FTDI_Chipi-X_FT6F1A7R-if00-port0 # Old gate
+    # usb-Prolific_Technology_Inc._USB-Serial_Controller_D-if00-port0  # Vxy
     # NVM = Keithley2182(interface='gpib', gpib_address=GPIB)
     NVM = Keithley2182(
         interface='serial',
-        device='/dev/serial/by-id/usb-Prolific_Technology_Inc._USB-Serial_Controller_D-if00-port0',
+        device='/dev/serial/by-id/usb-1a86_USB2.0-Ser_-if00-port0',
     )
 
-    print(NVM.set_integration_time(50))
-    exit()
-
-    print(NVM.set_range(1, 0.01))
-    print(NVM.set_integration_time(10))
-    print('Channel 1: {:.3f}uV'.format(NVM.read_voltage(1) * 1e6))
-
-    for i in range(0, 10):
-        print()
-        print('Channel 1: {:.3f}uV'.format(NVM.read_voltage(1) * 1e6))
-        print('Channel 2: {:.3f}uV'.format(NVM.read_voltage(2) * 1e6))
+    print(NVM.instr.query('*IDN?'))
+    print(NVM.set_range(1, 0.1))