I am having a problem with a Micrologix 1200 the com0 port keeps going out when I plug into my panelview C1000 please help. I have gone through two PLC's now and i am still not sure what is causing it. The system has been up for a couple weeks with no problems but today the com port went, had a new one couriered in installed and it, lasted about ten min. before the com port went on this one.