Power Supply Control Example

This Python script uses PyVISA to control a GW Instek GPD-4303S power supply. It sets a voltage and current limits for two channels, reads their output values, and determines their operating modes (CV or CC). The interface here is Serial over USB.

import pyvisa
import time

# Create a resource manager
rm = pyvisa.ResourceManager()

# Connect to the power supply (update the VISA address as needed)
ps = rm.open_resource("ASRL/dev/ttyUSB0::INSTR",
                    baud_rate=115200,
                    write_termination="\n",
                    read_termination="\r\n")
      
try:
  # Print the power supply model
  model = ps.query("*IDN?")
  print(f"PSU model: {model}")

  # Set voltage and current limits for channels 1 and 2
  ps.write("VSET1:10.0")    # Set CH1 voltage to 10V
  ps.write("ISET1:0.5")     # Set CH1 current to 0.5A
  ps.write("VSET2:19.0")    # Set CH2 voltage to 19V
  ps.write("ISET2:0.1")     # Set CH2 current to 0.1A

  # Turn output on
  ps.write("OUT1")

  # Wait 2 seconds
  time.sleep(2)

  # Read voltage and current values
  voltage1 = ps.query("VOUT1?")
  voltage2 = ps.query("VOUT2?")
  current1 = ps.query("IOUT1?")
  current2 = ps.query("IOUT2?")

  # Print voltage and current values
  print(f"Channel 1: {voltage1} V, {current1} A")
  print(f"Channel 2: {voltage2} V, {current2} A")

  # Check if CH1 is in CC or CV mode
  status = ps.query("STATUS?")
  
  # Remember that all commands return strings
  ch1_mode = "CV" if status[0] == '1' else "CC"
  ch2_mode = "CV" if status[1] == '1' else "CC"

  # Print channel modes
  print(f"Channel 1 is in {ch1_mode} mode")
  print(f"Channel 2 is in {ch2_mode} mode")

  # Turn output off
  ps.write("OUT0")

finally:
  # Close connection
  ps.close()
  rm.close()