{"id":15609,"date":"2025-03-18T16:44:30","date_gmt":"2025-03-18T16:44:30","guid":{"rendered":"https:\/\/www.dmcinfo.com\/blog\/15609\/using-a-switch-matrix-for-automated-testing\/"},"modified":"2025-12-23T09:45:37","modified_gmt":"2025-12-23T14:45:37","slug":"using-a-switch-matrix-for-automated-testing","status":"publish","type":"post","link":"https:\/\/www.dmcinfo.com\/blog\/15609\/using-a-switch-matrix-for-automated-testing\/","title":{"rendered":"Using a Switch Matrix for Automated Testing"},"content":{"rendered":"\n

Using a Switch Matrix for Automated Testing <\/h2>\n\n\n\n

In the world of Test & Measurement Automation<\/a>, a turnkey test system may have tens, hundreds, or even thousands of individual signals or signal pairs that need to be verified during a test. Switching and multiplexing are common ways to change a system’s hardware configuration by routing signals between the device under test (DUT) and a measurement device, power source, or other signal types to perform automated tests without having to manually disconnect or reconnect signals.\u00a0<\/p>\n\n\n\n

What is a Switch Matrix? <\/h2>\n\n\n\n

A switch matrix is a controllable hardware module that is comprised of switches organized into rows and columns that form a node or cross-point where each x-line (column) and y-line (row) meet. A switch matrix follows the matrix schematic, as described by documentation from National Instruments<\/a>. A sketch of a 10×6 switch matrix is shown below: <\/p>\n\n\n\n

\"10x6<\/figure>\n\n\n\n

This 10×6 matrix gives a total of 60 \u201ccross-points.\u201d Each cross-point is an intersection between an x-line and y-line. These cross-points can be energized to connect an x-line to a y-line or x-lines to other x-lines. This example shows a 10×6 matrix, however, switch matrices come in many different varieties and sizes.<\/p>\n\n\n\n

For example, Pickering Interfaces offers<\/a> PXI(e) \/ LXI \/ PCI matrices that vary by electrical ratings (current and voltage ratings) and number of crosspoints. To get a sense of the scale, a single high-density matrix can have more than 1,000 x-lines with over 4,000 cross-points! When specifying a switch matrix for your application, it is important to have a clear understanding of the maximum number of signals a system may need for a given test system along with the system’s electrical characteristics and requirements. There are even specialized switch matrices for high-current, high-voltage, and radio frequency (RF) signal types. <\/p>\n\n\n\n

Below we will explore the fundamentals of a switch matrix and how they can be used in an example automated test system:<\/em><\/p>\n\n\n\n

Connecting X-lines to Y-lines <\/h2>\n\n\n\n

For example, energizing\u202fnodes (9,2) and (10,1) will create a connection between X9 and Y2, and another connection between X10 and Y1.\u00a0<\/span><\/strong><\/p>\n\n\n\n

\"switch<\/figure>\n\n\n\n

Connecting X-lines to X-lines <\/h2>\n\n\n\n

Similarly, energizing\u202fnodes (1,1), (2,2), (9,2),\u202fand (10,1) will create a connection between X1\u202fand X10, and another connection between X2\u202fand X9.\u00a0<\/span><\/strong><\/p>\n\n\n\n

\"switch<\/figure>\n\n\n\n

Example Test System Hardware<\/h2>\n\n\n\n

Consider a DUT that has four data signal outputs and one power input. The test sequence required for this system is as follows: <\/p>\n\n\n\n