Connecting to Keithley 485 by Keithley in Python

Instrument Card

The Keithley 485 Autoranging Picoammeter provides 100fA sensitivity with 4 1/2-digit resolution in a low-cost, highly sensitive, easy-to-use instrument. The 485 measures DC current on seven ranges covering 10 decades from 100fA to 2mA. The input can withstand overloads as high as 1000V (with 100kΩ limiting resistor) for flexibility in a wide range of applications in test, research, and student labs. An analog output linearly converts the incoming current to voltage for hard copy output or control loop applications.

Device Specification: here

Manufacturer card: KEITHLEY

Keithley Instruments is a measurement and instrument company headquartered in Solon, Ohio, that develops, manufactures, markets, and sells data acquisition products, as well as complete systems for high-volume production and assembly testing.

• Headquarters: Cleveland, Ohio, United States
• Yearly Revenue (millions, USD): 110.6
• Vendor Website: here

Connect to the Keithley 485 in Python

Read our guide for turning Python scripts into Flojoy nodes.

Flojoy

PROTOCOLS > SCPI

📄 IDN

Query a device's identity through the universal *IDN? SCPI command.

📄 MEASURE VOLTAGE

Query an instrument's measured output voltage, such as a DMM or power supply.

📄 SCPI WRITE

Write a SCPI command to a connected bench-top instrument and return the result.

InstrumentKit

import instrumentkit as ik

# Connect to the Keithley 485 picoammeter
inst = ik.keithley.Keithley485.open_gpibusb("/dev/ttyUSB0", 22)

# Set the input range to 2e-9 A
inst.input_range = "2e-9"

# Enable zero check mode
inst.zero_check = True

# Enable log mode
inst.log = True

# Enable relative mode
inst.relative = True

# Perform a current measurement
measurement = inst.measure()
print(measurement)

This script first imports the instrumentkit module and then uses the open_gpibusb method of the Keithley485 class to connect to the Keithley 485 picoammeter. The method takes the device path (/dev/ttyUSB0) and the GPIB address (22) as arguments.

Next, the script sets the input range to 2e-9 A using the input_range property of the instrument. It then enables zero check mode, log mode, and relative mode using the corresponding properties.

Finally, the script performs a current measurement using the measure method of the instrument and prints the result.

Note: This script assumes that you have already installed the Instrumentkit library and have the necessary permissions to access the GPIB device.