Dryhops
Member
I have a CompactLogix 1756-L72/B with only an EN2TR/C in a 4 slot chassis. Port 2 of the EN2TR is connected to two POINT I/O racks, while port 1 is connected to the local port of an 9300-ENA. The Uplink port then connects to an unmanaged N-Tron 108TX switch in our SCADA network. I should note that the run to the unmanaged switch is about 230 feet with shielded cable.
Since installation, this setup is plagued by connectivity issues. Our HMI loses connection every 5 seconds or so, and regularly goes in an out. Investigating, I found that port 1 of the EN2TR is slowly accumulating FCS errors and MAC receive errors (2 or so a minute). Documentation about these errors is sparse, but I have tried:
-Confirming auto-negotiate is on - both ports are in auto, and the switch is unmanaged.
-Ruling out EM interference by swapping the 230' cable with one that I ran directly between the panels, so a shorter run that isn't in the cable tray
-Bought a cable tester to ensure they were built properly. Both cables passed (this was just a small fluke meter, I don't know if it would catch more insidious wiring problems)
-Swapped ports 1 and 2 on the EN2TR, port 2 then began to see errors so I ruled out EN2TR hardware failure.
-Tried different ports on the switch. If I stare like a madman at the LED lights, I can see that while the other ports are all blinking continuously, the problem port is blinking, then going solid for a fraction of a second.
-I ran a wireshark capture of the traffic between the controller and the HMI server, which I attached a screenshot of errors that were caught. I do not have the expertise to decipher them unfortunately.
Does anyone have some insight as to where this might be going wrong? I suspect the NAT device since the FCS and MAC errors are only generated on the port connected to it, but I can't justify replacing it without some evidence that it is to blame.
Since installation, this setup is plagued by connectivity issues. Our HMI loses connection every 5 seconds or so, and regularly goes in an out. Investigating, I found that port 1 of the EN2TR is slowly accumulating FCS errors and MAC receive errors (2 or so a minute). Documentation about these errors is sparse, but I have tried:
-Confirming auto-negotiate is on - both ports are in auto, and the switch is unmanaged.
-Ruling out EM interference by swapping the 230' cable with one that I ran directly between the panels, so a shorter run that isn't in the cable tray
-Bought a cable tester to ensure they were built properly. Both cables passed (this was just a small fluke meter, I don't know if it would catch more insidious wiring problems)
-Swapped ports 1 and 2 on the EN2TR, port 2 then began to see errors so I ruled out EN2TR hardware failure.
-Tried different ports on the switch. If I stare like a madman at the LED lights, I can see that while the other ports are all blinking continuously, the problem port is blinking, then going solid for a fraction of a second.
-I ran a wireshark capture of the traffic between the controller and the HMI server, which I attached a screenshot of errors that were caught. I do not have the expertise to decipher them unfortunately.
Does anyone have some insight as to where this might be going wrong? I suspect the NAT device since the FCS and MAC errors are only generated on the port connected to it, but I can't justify replacing it without some evidence that it is to blame.