1756 L81 v.30.00 ESM module fault disappeared

Hello,

I had an out of box controller 1756 L81 Contrologix. Was running for about a week and started getting the ESM fault. Powercycling did nothing. I downloaded the program again to flash and the ESM error went away. Maybe 2 days later it reappeared. Downloading to the controller would clear it temporarily.

This particular unit doesn't have a removable module. You have to replace the whole controller.

I have since put a blank program in the controller and left powered on for 2 weeks. The ESM fault has not occurred again.

Has anyone else experienced this? Is the battery good or should I just get a new controller?

if you bought the unit from an ab rep, call them up and explain the issue. they should take the unit back as defective since the unit is not that old. we have done this 1 or 2 times.
james

Is the PLC in a temperature controlled environment?

I've had issues with the new series and faulting after being stored in a cold environment, when PLC came back to an OK temperature the fault cleared after a couple of power cycles.

check this technote from AB
ESM fault scrolling across the 1756 controller display
https://rockwellautomation.custhelp.com/app/answers/answer_view/a_id/636269