SLC 500 help, please

Hi everyone, my current company have lost most of our PLC guys, so I'm it for now!
I have some experience with AB, Omron and S7 and I'm getting better the more I do.
However, I need some advice. We have a plant with SLC 500[not sure which proc], running a Devicenet network of Nodes, 1 AB HMI installed. The plant was commissioned about 6 weeks ago, has been running OK but now the PLC has stopped running.
We believe the proc has 'locked out' due to a 'buffer overflow' from some trending that is running.
I have had some advice that this is poss due to failing to 'clear the carry' in math fuctions.
Is there a way of clearing the overflow without going into the program. I only ask as the plant is a 5 hour drive away!

Standing by.

I assume they tried recycling power to the system. If its a Major fault then you will probably have to go onsite to clear it but if you do then you may want to setup a modem so you can have dial in access in the future. To be prepared I would have them find out what processor it is, check the LEDs and match them to the manual. If possible make sure there is a copy of the program available.

If you have a math overflow error...the value will be held and the error will return. I would caution you against resetting any error that you did not identify. For it will surely return at an even more worse time.

Can you download the program in the faulted state from the processor and post the .rss file here. It'll tell alot.

OK, thanks guys.

The client has cycled the keyswitch from run-stop,etc several times and in doing this has released some of the cpu memory. This enabled him to get the PLC into run mode as a temporary fix until we can get to site.

I'll post the rss file when I get a copy.

I'm on another site for the rest of the week commissioning.

See ya.