Power supply and control units for a 19-inch HIL test bench

Challenge

For a 19-inch HIL test bench, the client needed two core assemblies: a power supply that feeds the device under test and the bench and provides the necessary measurement, and a controller for digital signals. Both had to integrate into the existing test framework with little effort.

Approach

We designed and built both rack modules and connected the software to the test framework.

Power supply unit (PSU)

• Mains inlet via CEE connector, outlets for the device under test at 400 V and 230 V plus an additional 230 V socket
• 5 V and 24 V supply for the test bench, with fuses accessible from the outside
• Power consumption measurement with a display in the front panel
• Indicator lights for the device supply, 5 V, 24 V and the three phases, plus emergency stop and main switch
• Signal interface to the test bench via a D-sub connector

Control unit

• 32 digital inputs and outputs based on a compact CODESYS controller (Raspberry Pi with PiXtend modules)
• Clear wiring via terminal blocks, signals handed over via D-sub connectors

Software integration

• Connection to the client’s test framework via the CODESYS controller and OPC UA
• Support for the client in building their own user interface for the test bench, which talks to the controller over the same interface

Outcome

The result is a lightweight, cost-effective solution that has already proven itself in demanding continuous operation. Because OPC UA is widely used in industry, the client was able to build the user interface themselves with our support.

The interface lets the team at the bench follow automated test runs live. Errors or unexpected system behaviour stand out immediately and can be fixed quickly.

HIL, thought through end to end

Our solutions do not stop at the hardware of a HIL test bench. We think about HIL as a whole – from the testers’ point of view and with the needs of the organisation in mind.

More about our HIL test benches.