AB PLC 5/11 Lost Program

We have a AB PLC 5 system with a 1771-OVN module has no indications lit although the other IO modules have indicators lit. During hurricane Harvey the system was powered down for several days. When power returned the system did not return to operation. We checked the battery and it was less than 2 vdc. Proc light is on RED and the green A light flashes on and off. From what i have read it seems the program is gone. Any opinions or suggestions on how tell if the program is still there? This system is of course old and we do not have the programming software.

Thanks

Call your local AB rep. You will have to go online to see if the program is there.
You need the programming software to do this.

Hopefully you have a back-up of the program somewhere.

AB PLC 5/11 lost program

Thanks Mickey that's what I thought.

The PLC-5/11 has a memory module slot on the front of the controller, between the status LEDS and the battery cover. If there is a memory module installed, it's possible that the program is stored there and it just requires a technician to go online and command the transfer from EEPROM to RAM.

If the memory module is not installed, then the program is definitely lost from the controller and it will need to be reinstalled from an archive.

This is bread and butter work for most automation system integrators. If you don't have one you use regularly, call your local A-B distributor (for Houston, it's Reynolds Company) and ask for their recommendation.