We have an OPC server getting data from a Compactlogix PLC. The PLC also communicates with a Panelview and a couple VFDs via Ethernet/IP. Everything seemed to work fine for a year or so and all of a sudden the OPC server stopped communicating with this PLC. It still works fine with a few other Compactlogix PLCs.
Here's the odd part. Unplugging one of the VFDs from the ethernet switch in the control panel will cause the OPC server to start working again. Plug the VFD back in and the OPC server stops. We suspected an IP conflict but we verified that everything is set correctly.
I'm suspecting the ethernet switch, but everything else on the same switch works ok.
Here's the odd part. Unplugging one of the VFDs from the ethernet switch in the control panel will cause the OPC server to start working again. Plug the VFD back in and the OPC server stops. We suspected an IP conflict but we verified that everything is set correctly.
I'm suspecting the ethernet switch, but everything else on the same switch works ok.