Emerson PAC/RX3i CPE305 Controller - Troubleshooting/Viewing Eth. Ref. Address

[MichaelIEC]

Hello all,

First time poster, long time viewer of these forums. Could not find my solution on here.

We have had issues with a Comm Fail on an important electrical component of our system. SCADA is showing comm fail, because of two status bits. I have checked components and replaced radio(also verified other components).

Contractor has changed Ref. Address. (reference off RJ45 CPU ETHERNET data) along with variable tag. Old and new variable bits are not changing via Data Watch. But I cannot seem to find an issue in the logic and/or variables.

Nothing has been rewired, only component that has been replaced is the radio, and I have confirmed it is communicating. I can remote into all devices on the system after installation. I have tested the MODBUS to Ethernet switches to radio and have not seen any issues.

There is ladder logic that toggles the Read/Write status bits every two minutes and we get updated data. However the status goes FALSE right after the 3 second delay.

Is there any way to view diagnostics on a channel coming through the Ethernet port on the CPU? I've watched the reference bit via Data watch, and nothing has changed besides the 2 minute force reset.

I have checked PLC Diagnostics and no issues at all.

Thanks,
Michael

 

[Steve Bailey]

Is the communications between the SCADA and the PLC actually going down? Or are the two status bits you're monitoring not behaving the same as they were before the contractor worked on the equipment? Are the two status bits controlled by the logic in the PLC?

 

[MichaelIEC]

It is polling the READ/WRITE request on a forced reset via PLC and only updating then(every 2 minutes). The comms between the PLC and SCADA is NOT going down because we have other components that are working.