Intermittent Modicon issue - Loose Drops

[billhenry]

We have been experiencing an issue over the last 4 - 5 days with one drop of our Modicon Quantum system.

Symptoms:

Communication loss on drops.
Panel Screen Indications will flash State (ON & Off)
Starters in the field will also cycle on & off.

Had Square-D Modicon Tech onsite, Checked all Drops, Replaced one Connector.
Found nothing wrong. Ran for 12 hours and issue appeared again.

Traffic cop does not indicate an issue.

Any help would be greatly appreciated.

 

[Jim Dungar]

Check your bonding (grounding)between your remote devices.

 

[OZEE]

Good luck...

We've been battling this for years in one of our plants. He specialist in who redid all of the cabling/connectors. Swapped out comm-cards. Rerouted cabling. Grounding all fixed.

The only thing that seems to work is converting them to ControlLogix.

 

[billhenry]

Thanks,

We have been going through the Status Words. Comparing the Counts for any errors. Issue being these have not been reset for so long we are unsure the timelines.

I did notice a CRC Error is indicated on word 175. I have some E & I techs out checking the bonding at the moment as well.

Thanks for the responses.