# Communication Problems Pic 900 controller



## sparkywannabee (Jan 29, 2013)

I had a similar issue on a Siemens plc long time ago, make sure your hot and neutral wires to your I/O modules are good and snug, you might be having momentary loss somewhere, really hard to catch this in the act sometimes. Good luck, I am sure you'll 'git er figgered' out.


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## ilikepez (Mar 24, 2011)

Got it figured out. The manual and the plans have different pinouts for the com connector, the ground wasn't plugged into to the right pin. After changing that we haven't had any problems.


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## adamc (Sep 27, 2013)

SCORE !

I have also over the years, added UPS units to ALL
of our PLCs and comms equipment. this has greatly reduced
many of the glitches.


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