slc5/01 not holding program

[fredbloggs 0]

hey all, first post on this forum. i have a fair bit of plc experience, but not much with ab. im looking for some help with and slc 5/01. when the power to the plc goes off, the program in the plc is lost. when powered back up it reprograms ok. i have replaced the battery and checked what i can. is it a problem with the memory module (if it has one)? has anyone else come across a similar problem? any help much appreciated thanks james

[Ken Roach 194]

SLC-5/0x modular controllers can hold the program for days just using the onboard capacitor, and for years with the battery. So losing a program on power cycle means there's something serious wrong with the controller. The memory modules are in a very prominent socket on the circuit board; if you have one there, pull it out and see if the controller loses its program again on the next power cycle. The 5/01 could be directly replaced with a modern 1747-L531 (SLC-5/03) controller with no translation or modification of the project (other than specifying the new controller model number).

[slcman 9]

The plc may have a Eeprom. After downloading the program, try to burn the Eeprom: go in Comms -> Eeprom... -> Store to Eeprom. You can also check in status file ->Mem module. If S:5/8, S:5/11 or S:5/12 is set, the plc will load pgm from Eeprom at power up. I send 2 pdf in my post for give you some info on Eeprom on slc. One of them will show you where is the Eeprom on the controller. If you don't have a Eeprom and no low battery light, I think you have a defective plc. good luck Eeprom.pdf Eeprom_location.pdf