Fundamentals of Building a Test System: Switching and Multiplexing

Many automated test applications require routing signals to a variety of instruments and devices under test (DUTs). Often the best way to address these applications is to implement a network of switches that facilitate this signal routing between the instrumentation and the DUTs. Switching not only handles this signal routing, but it is also a low-cost way to increase the channel count of expensive instrumentation while increasing the flexibility and repeatability of your measurements.

When adding switching to an automated test system, you have three main options:

1. design and build a custom switching network in-house,
2. use a stand-alone box controlled via GPIB or Ethernet, or
3. use a modular platform with one or more instruments such as a digital multimeter (DMM).

Switching is almost exclusively used alongside other instruments, so tight integration with those instruments is often a necessity. An off-the-shelf, modular approach can meet these integration challenges inherent in most common test systems. This guide will outline best practices for integrated switching and multiplexing into your test system.

Ensure you’re creating a successful automated functional test system with this guide on Switching and Multiplexing.