I had an L55 version 15 crash this past weekend. I came in to find the processor down.
I could not get online with the processor, so I pulled it and reseated into the back plane.
I tried to check the fault code, but it basically said there was not program in the processor.

The L55 is running version 15 software. I am using the large back up battery.
The power is clean. I use a UPS to feed the power to the PLC equipment.
There processor is in a rack with communication cards only. E/Net, C/net and R I/O.


I put another processor in the rack and reloaded the program.

This is the 2nd time this has happened in the past few months.

Does anyone have any ideas as to what caused this?

I am thinking of replacing the power supply during out July shutdown?
Could a number overun cause this? I could check the program for number overun.

Thanks for any help.

Here is an update. I spoke with TechConnect and he suggested a software update.
I am currently using V15.3 and there may be a bug in the software that could cause this.
I will update to the latest version 15.

You were pointed to the known anamoly in L55 ver 15
It is fixed in ver 15.5
But to correctly identify the problem, call techsupport and ask for Fault Dump utility to recover debug file from controller
Debug may tell what actuually happened without a guess.

We talked about that, but the processor was pulled from the rack and the battery was not attached.
I guess I should get the fault dump utility incase it happens again.