SLC DH485 Problem

I posted a topic a few days back about an SLC 5/03 that was "dying" for unknown reasons. Well I sent a guy that works for us on a contract basis who lives in the state where the SLC is located to investigate the situation more thoroughly. He reports back that he believes the Processor is being subjected to something damaging across the DH485 line. The DH485 is connected through an AIC that connects 2 PanelViews and one remote PC node. My question is: Is it possible to create an unrecoverable fault to a processor through a Comm port. The system works fine 99 percent of the time. This problem only happens after the system has been online for about a week. The system is currently DOA until we can determine the cause since processors are in the thousand dollar range. Anyway, if this is possible then does anyone have any suggestions on what would make this happen. Thanks in Advance.

Eagle Electric

dh485

I had the same problem with a SLC 5/03 on a Edge Gluer at our Meridian Plant which also had a panel view hooked up to it.
After losing one panel view and one processer and having to re- program the PLC several times over a one year period, Because the PLC would lose its program for what I thought was no reason. I started tracing wires and found that the manufacture of the machine had hooked the PLC ground wire to the chassie of the machine. I removed that ground and hooked the PLC and the panelview to a earth ground and I havent had a problem since.