Random MSG error

I am communicating with a Kinetix 300, a Powerflex 525, and a Micrologix 1100 via Ethernet/IP using MSG instructions. They are all linked through a Stratix 2000 un-managed hub.


Everything works fine...most of the time. Every once in a while I will get a MSG error. Often happens on startup. I have written the logic so that it will continue to attempt communication until the error goes away. It usually does after a few minutes. Sometimes the error is while trying to communicate with the Powerflex but more often it is with the Kinetix 300.


I even tried to eliminate the hub and just direct connect the ML1100 to the Kinetix 300 with an extra cable that I had. Still got the random error. Again it corrected itself but I really can't have that happen for no apparent reason.



I know that you don't know the exact situation but I wondered if someone might have an idea about what it might be?

Well, what is the error code in the MSG instruction?

You can trap the error code by using the MSG.ER bit to copy the MSG.ERR code to a 'last MSG error' tag.

Two things that make noisy motor outputs along with a plastic-chassis PLC controller spell electrical noise interference with networking signals.

Make sure that MicroLogix and the Ethernet switch are very well grounded, and that the whole enclosure and the VFD and servo cables are all also very well grounded. Route the Ethernet cables as far away from the motor output cables as you can.