CompactLogix Fault?

I have a project developed over a year ago using a CompactLogix and a PanelView Plus. Ethernet connected. Programmed, debugged and shipped.

Equipment is only now being installed. Field installer has been running equipment with CPU key in Remote Mode. No problem.

This morning, the key was turned to Run Mode and the installer could only get a flashing OK light. PanelView had made some startup screen changes (all are initiated within the PLC program) but ceased to respond to user input when the OK light began to flash. Did some research and the OK flashing indicates a Major Fault. He has no way to clear a major fault (no PC or software).

Tried to power down and then power up in Remote (since this seemed to work previously). No joy. Thought that I was going to have to schedule a flight out. Called me back a couple of minutes later letting me know that he powered back down, turned the key to Program Mode, powered back up and all was right with the world. Then he was able to turn the key back to Run Mode.

After he has completed some testing, he'll see if he has the ability to restart the PLC with the key in Run. Can anybody explain what happened and how to avoid this in the future?

... rab

The only way I can think of to tell what happened is to go online with the PLC and under Controller Properties check the Major and Minor Fault tabs.

some faults can be cleared by using key switch by changing it to Program--remote---Run

To troubleshoot the problem you need the cable & software