modicon

[wwlyons]

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

 

[Sliver]

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

 

[wwlyons]

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

 

[gleon]

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.

 

[Sliver]

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.