I try to write a skript to run my measurement on a Keithley 6487. To get comfortable I wrote a small skript to play around but have trouble with the readout of voltage and current. I have little experience in writing pyvisa code for Keithley 2600 series but not for this one. The user manual also does not help very much. In the following code when "(...)device.query('MEAS:VOLT?'))" is reached the error "ERR -133" gets thrown which I looked up in the manual but dont know how to continue from here. I hope you can help me. Im connected via RS-232 since its the only "to-usb-adapter" I have at the lab here.
import pyvisa
import time
import csv
def test_keithley_6487():
# Create a resource manager
rm = pyvisa.ResourceManager()
# List all connected resources
ports = rm.list_resources()
print("Available ports:", ports)
# Output file for logging measurements
output_file = "keithley_6487_measurements.csv"
# Attempt to connect to the Keithley 6487
for port in ports:
try:
# Open the resource
device = rm.open_resource(port)
print(f"Connected to device at {port}")
# Query device identification
idn = device.query('*IDN?')
print("Device ID:", idn)
# Set communication parameters (if necessary)
device.baud_rate = 9600
device.data_bits = 8
device.parity = pyvisa.constants.Parity.none
device.stop_bits = pyvisa.constants.StopBits.one
device.timeout = 5000 # 5 seconds
# Set and measure voltage and current in a loop
for voltage in [1.0, 2.0, 3.0, 4.0, 5.0]:
# Set the voltage
device.write(f'SOUR:VOLT {voltage}')
print(f"Set voltage to: {voltage} V")
# Wait certain amount of time (e.g. 2 sec)
print("Going to wait 2 seconds") # Debug
time.sleep(2)
# Measure voltage
print("Trying to read voltage...")
measured_voltage = float(device.query('MEAS:VOLT?'))
print(f"Measured voltage to be {measured_voltage}") # Debug
# Measure current
print("Trying to read current...")
measured_current = float(device.query('MEAS:CURR?'))
print(f"Measured current to be {measured_current}") # Debug
# Set voltage back to 0.0 V
device.write('SOUR:VOLT 0.0')
print("Voltage set back to 0.0 V")
# Close the device connection
device.close()
break # Exit loop after successful connection
except Exception as e:
print(f"Failed to communicate with device at {port}: {e}")
if __name__ == "__main__":
test_keithley_6487()
