G303 HMI and Direct Logic 5 PLC not communicating

So I have a set up with a Red Lion G303 HMI and a Direct Logic 5 PLC in a heat treater panel. Until a week ago, everything ran great. Then the screen just started showing dashes for all settings on the HMI. I have tried two PLCs with two HMIs and new comm cables, but I get nothing different. The PWR and RUN leds are lit on the PLC. I have no way of testing programs but find it hard to believe that two units lost their program especially when one of them was never connected. Any ideas? Any one in the Atlanta area want some freelance work?

What is a "Direct Logic 5 PLC"? Can you provide a link. I don't recognize that model.

http://www.automationdirect.com/adc...tLogic_05_(Micro_Brick_PLC)/PLC_Units/D0-05AA

This is the model we are using. It has a F0-04RTD input module as well. I have changed it out too.