rickyv

Double check and make sure your outgoing from your first panel is the inocoming next and so on. Again, if these get switched, it will cause communication problems. Of course, there is always a possibility that one of the panels is bad causing this. You could aslo remove the loop from the first panel and twist the wires together and see if the second panel works. That might help isolate which panel might be bad.

You are not communicating with the panel or panels. How many panels are on this loop? Make sure you are feeding in and out of the panels correctly. The C100 uses a 20ma loop. It's critical that the loop feeds each panel correctly then returns back to the C100. If these pairs get crossed or the incoming and outgoing from each panel gets crossed, this is the result.