AB SLC500 PLC: 1747-L511 5/01 CPU 1K Mem.

[z-k 0]

Hello, Everyone, I am a new one and have a question to ask someone who knows. Thanks in advance. SLC500 1747-L511 5/01 CPU 1K Mem PLC: When I changed the program offline and downlaoded to PLC - using Comms - EEPROM - Store to EEPROM. But I turned off the power, waited 5 minutes, then turn the power on, the program would come back to the previous one. I don't know why... z-k

[Firetubes 1]

Did you set any of the Load Memory Module bits? If not, check out bit S:1/10, 11 and 12.

[Ken Moore 23]

Sounds like you were not able to write to the EEPROM. I do not remember the exact verbage, but when you are "burning" the EEPROM, the software ask if future writes are allowed. If the original programmer chose not to allow future writes, then you will have to replace the EEPROM. Ken

[Mr38 0]

I'm new to PLC's too, I only have a SLC 500 I have been playing with. But could you not just take out the Eprom and load the new program to the PLC memory and run like that?? I have been using mine and don't have an Eprom at all only using the regular memory. ?

[gravitar 3]

That sounds like the logical first step in the troubleshooting process. Make sure the SLC alone, no EEPROM, can save and reboot from your program. Then (after powering down of course) pop the EEPROM back in, try to write to it, and see if it retains the correct revision of the program after a restart. I would HOPE that RSLogix would tell you if the EEPROM write was not successful. But who knows, maybe it doesn't. I've never wasted an EEPROM by setting the "read only" flag.. Incidentally if you think you need to buy another EEPROM, there's a guy on ebay that sells them for $12. Take a look at auction #7510854056. (No it isn't me, and I have not bought any from him (yet) but as luck would have it he's only a couple miles away from me!) Edited 5 May 2005 by gravitar

[z-k 0]

Many thanks to Firetubes, Ken, Mr.38 and Gravitar. When I downloaded the new program to this PLC, it could run properly. The only problem is that I couldn't store the new program into the EEPROM. I will try all your suggestions and let you know the results later. Thanks again. z-k