We are investigating available libraries and frameworks for automated PLC unit testing in Schneider EcoStruxure Machine Expert.
Specifically, we are looking for:
Assertion libraries or test frameworks compatible with Machine Expert
CODESYS‑based solutions that are not TwinCAT‑specific
Any official or community‑recommended approach for unit testing FB/FC logic offline
We have found several open‑source examples, but many appear to be TwinCAT‑dependent and therefore not compatible.
Are there any known libraries, best practices, or recommended approaches for implementing unit tests in Machine Expert?
Thanks in advance.
If you would like to refer to this comment somewhere else in this project, copy and paste the following link:
If the Professsional Developer Edition (which includes the Test Manager) is not supported by Schneider, then an option is to use the Open Source Unit test framework. See: https://forge.codesys.com/lib/counit/home/Home/
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Last edit: TimvH 2026-02-20
If you would like to refer to this comment somewhere else in this project, copy and paste the following link:
Hi,
We are investigating available libraries and frameworks for automated PLC unit testing in Schneider EcoStruxure Machine Expert.
Specifically, we are looking for:
Assertion libraries or test frameworks compatible with Machine Expert
CODESYS‑based solutions that are not TwinCAT‑specific
Any official or community‑recommended approach for unit testing FB/FC logic offline
We have found several open‑source examples, but many appear to be TwinCAT‑dependent and therefore not compatible.
Are there any known libraries, best practices, or recommended approaches for implementing unit tests in Machine Expert?
Thanks in advance.
If the Professsional Developer Edition (which includes the Test Manager) is not supported by Schneider, then an option is to use the Open Source Unit test framework. See:
https://forge.codesys.com/lib/counit/home/Home/
Last edit: TimvH 2026-02-20
Thank you, I will try it!