Use PyVISA to Program Test Tools with Python - Workbench Wednesdays

TL;DR

This video demonstrates how to use Python and Pi Visa to automate test equipment, making repetitive tasks faster and enabling measurements that the tools cannot do natively.

Transcript

hello and welcome back to workbench Wednesdays my name is James and in this video I show how a few lines of python code can automate a bunch of test equipment learning how to do this can help you speed up repetitive tasks and perform measurements your test tools do not do natively and it's just fun to write a simple test script that makes all kinds... Read More

Key Insights

• 🍎 Automating test equipment with Python can help speed up repetitive tasks, perform measurements, and make cool test actions happen.
• 💻 Using a Raspberry Pi with Linux and Python is a great option for automation, but any Linux and Python setup should work.
• 🔌 Tools with USB, LAN, or serial ports are the focus of automation. Connecting via serial ports can be easier with a serial to USB cable.
• 🔧 The Pi Visa module is a Python wrapper that interfaces with the Visa driver, allowing software to communicate with instruments using Skippy commands.
• ✉️ Skippy commands consist of a command and parameter section, with optional choices and levels of commands separated by colons. Certain characters like asterisks, semicolons, and question marks have special meanings.
• 🧰 Pi Visa Dash Pi is an open-source Visa driver that can be used with the Pi Visa module. Visa drivers from different manufacturers have different licensing terms.
• 🔌 GPIB, LXI, RS232, and USB TMC are real interfaces used in test and measurement. GPIB is the general-purpose instrument bus, LXI is an Ethernet-based interface, RS232 is a serial communication interface, and USB TMC is a replacement for GPIB using USB.
• 🧪 Automating measurements can replace manual processes and make testing faster and less error-prone. Connectivity to instruments can sometimes be a challenge, but there are solutions available.

Questions & Answers

Q: How does the Pi Visa module facilitate communication between software and instruments?

The Pi Visa module acts as a python wrapper that interfaces with a Visa driver, enabling software to send commands formatted according to the Skippy command set for programmable instruments to communicate with the instruments.

Q: Can the video's automation methods be applied to any test equipment?

The automation methods demonstrated in the video can be applied to any test equipment that supports USB, LAN, or serial communication and can be controlled using Skippy commands.

Q: What are the advantages of automating test equipment using Python and Pi Visa?

Automating test equipment using Python and Pi Visa offers several advantages, including faster execution of repetitive tasks, the ability to perform measurements beyond the native capabilities of the equipment, and the joy of writing customized test scripts.

Q: How does the video address the challenges of connecting and communicating with instruments?

The video discusses the different instrument connections (gpib, LXI, rs232, and USB TMC), the availability of Visa drivers from various manufacturers, and the need to carefully read the licensing terms for using proprietary Visa software. It also provides troubleshooting tips for common connection and communication issues.

Summary & Key Takeaways

• The video shows how to use Python and a Raspberry Pi (or any Linux computer) to automate test equipment with USB, LAN, or serial ports.

• The Pi Visa module is used as a python wrapper that interfaces with a Visa driver, allowing software to communicate with instruments using Skippy commands.

• The video also explains the concepts of virtual instrument software architecture (Visa), API, different instrument connections (gpib, LXI, rs232, and USB TMC), and the challenges of connecting and communicating with instruments.