The Industrial Raspberry Pi Forum

Hello,
We have an AIO module with 4 input signals - all of them - 4-20Ma - same sensors. Channels 2,3 and 4 are working fine but we cannot see anything from Ch_1. We swaped the sensors to be sure that we have signals comming from them.
It seems the Ch_1 doesnt work. Is there any tool or way to check / test the input channel if it is faulty ?

Hi, your thoughts on changing the channel were great. Here is a tutorial how a simple analog measurement is possible.
https://kunbus-gmbh.atlassian.net/servi ... -810880902

If you connect an output to the desired input, you can do a simple self test.

But it is important to understand that if you go this way you have to disable CODESYS because otherwise it overwrites the process image and your changes via the command line will be overwritten in milliseconds…