5069-IB16 inputs not making when VFD (PowerFlex 525) is running

[phuz]

This is a new one to me. We thought we were having sensor issues when trying to commission a new machine, but realized that the inputs were not lighting up on the 5069-IB16 despite there being 24vdc at the terminal. I was able to isolate this to when one of the conveyors (1/2hp motor) was running. The signal wires are not run near the VFD power wires. The moment the VFD stops, the signal inputs indicate correctly on the module (and in the PLC code). Even more odd, this only seems to affect one of the two IB16 modules, leading me to believe maybe there is something wrong with the card. We have bonded everything and ensured good grounds on this relatively small machine and running out of ideas. I will be back with this customer on Thursday and will bring a spare 5069-IB16 module, but I'm not entirely hopeful.

Electrical gremlins like this are tough!

 

[rupej]

There is a well-known issue with that card. Open the module properties in Studio 5000, navigate to "Points". Set the input filter times all to 0us.

The issue is the card is so sensitive that it picks up enough noise that the input doesn't stay on or off long enough to pass the filter, and the point "freezes" in its last state until the noise goes away.

Hopefully that's what the problem is this time!

 

[phuz]

There is a well-known issue with that card. Open the module properties in Studio 5000, navigate to "Points". Set the input filter times all to 0us.

The issue is the card is so sensitive that it picks up enough noise that the input doesn't stay on or off long enough to pass the filter, and the point "freezes" in its last state until the noise goes away.

Hopefully that's what the problem is this time!

You just saved us a ton of further torment. I should've posted this two hours ago when we first noticed it. Unbelievable. In all the years I've been using these 5069 modules, I have never experienced this with the IB16. I've run into the issues when using 120vac with the OW16 modules, though.

Thank you so much for this quick fix.

 

[rupej]

Glad it worked! Yeah that bit us once a few years back, incidentally also with a 525, and ever since then I just turn the filter off on all projects now. Never had any issues since.

 

[jstolaruk]

Ran into this exact scenario when the panel builder didn't follow the design and skipped using shielded motor runs from the VFD.