modicon

I have a modicon PLC connected to a panal mate HMI and often enough I lose communication the cable has been replaced. any ideas?

Are you getting an error banner on the bottom of the panlemate LOC (loss of Comms) as if you have removed the cable?

yes I do it seems like a serial cable problem, most of the time this happens during boot up, only once during a run.

You can check that the communications cable doesn't run near any power lines. I've had a couple of problems with intermittent communications because of this.

Other than all the basics of shielding, loose connections/vibration, cable too long (RS232 >100'), the only thing I have experienced is in home-made cables and bad solder joints, If yours is a molded plug DB9 on both ends then you are probably ok on that issue.

Brian.

PS -- Is it happening on the bootup of the panelmate or the PLC, Obviously if you shut down and reboot the PLC you will get LOC.