Hello PLC friends. I've been going through a saga of diagnosing and fixing an old PLC setup that I inherited. I am learning as I go.
Initial Error was in temp readings associated with a 1746-NT4 thermocouple module. Saw temps going off the rails. But also experienced communication errors with SLC 5/05 that appeared as Error 612 or 613 on our PanelView. Could thermocouple module failure propagate to SLC 5/05?
We replaced the 1746-NT4 module and our temps looks normal. But our SLC 5/05 starts up in Fault mode. We switch Key to program and push the configuration file to it and then go back to Run and it's happy. But if we power cycle we start back up in fault mode.
Troubleshooting steps:
1) Replace Battery 1747-BA on the SLC 5/05. No change (new battery measured 3.0 V open circuit prior to install)
2) Replace SLC 5/05. No change (same behavior with new module!)
3) Replace Power Supply Module. No change
Questions:
1) Are both of these CPUs bad?
2) Am I doing something that breaks these SLC 5/05 modules in the same way?
3) Is the setup/procedure bad and the modules are just fine?
4) Are the batteries crazy old and we need new ones?
Thank you for any insight!
Initial Error was in temp readings associated with a 1746-NT4 thermocouple module. Saw temps going off the rails. But also experienced communication errors with SLC 5/05 that appeared as Error 612 or 613 on our PanelView. Could thermocouple module failure propagate to SLC 5/05?
We replaced the 1746-NT4 module and our temps looks normal. But our SLC 5/05 starts up in Fault mode. We switch Key to program and push the configuration file to it and then go back to Run and it's happy. But if we power cycle we start back up in fault mode.
Troubleshooting steps:
1) Replace Battery 1747-BA on the SLC 5/05. No change (new battery measured 3.0 V open circuit prior to install)
2) Replace SLC 5/05. No change (same behavior with new module!)
3) Replace Power Supply Module. No change
Questions:
1) Are both of these CPUs bad?
2) Am I doing something that breaks these SLC 5/05 modules in the same way?
3) Is the setup/procedure bad and the modules are just fine?
4) Are the batteries crazy old and we need new ones?
Thank you for any insight!