Allen Bradley SLC 500/01 Lost Program

[dogwood8488]

Hello

I have a SLC 500/01 processor that lost it's program after power supply failure. It has an EEPROM installed and I am hoping it is up to date with the program backup, however I cannot get it to load or read from the EEPROM. I wrote a 3 rung program and downlaoded it and got the processer out of the fault state. While online I try to make it read from the EEPROM and I get an alarm message and immediately goes offline. The alarm message implies that the communications setup has changed.

Any Help apprciated.

 

[Tharon]

I believe that when you load the program, and the communications settings are different, you will get a warning telling you this. You will be able to choose to apply the changes or not.

If you don't have anything communicating to the processor, you can choose not to apply the communication changes, and it's current settings (that you are using to communicate) will be kept.

This will let you stay online, place the processor in RUN mode, etc.

 

[dogwood8488]

I have seen what you are talking but this is different, No warnings, just goes offline immediately when you try to load from eeprom. I can go back online so nothing is changing as far as the communication settings are concerned. It is as if the communication settings in the eeprom project are different from what is in my online project. It is DH485 only so what could be different?

 

[bernie_carlton]

Has this unit ever successfully loaded from this EEPROM? Is it possible it is from another model SLC?

 

[OkiePC]

Have a look at the Processor Status file (structured view). If the EPROM is successfully loaded, there is a Status bit to indicate that (at home without RSLogix500 to look it up.)

If that bit never gets set, you probably don't have a valid program burned on the EPROM.

Have you tried shorting VBB to ground with the battery unplugged? If the EPROM is configured to load on memory error, this should trigger it.

If that method fails too, you need to start hunting down the .rss file for that machine. (You need to do this anyway.)

 

[dogwood8488]

To my knowledge Loading from EEPROM has never been tried. I set the status bit that loads from eeprom on power up but nothing happens. Machine was new in 1992. It is possible that there is nothing in the EEPROM. OEM is no longer in business and latest changes were made 5 years ago when a modification was made to the machine, Tech that made changes is trying to be contacted to see if he still has a backup. So far not been able to contact this Tech.

 

[OkiePC]

While you wait for that miracle, how feasible is it for you to whip out a new program for this machine?

Do you have accurate electrical and mechanical diagrams of the machine?
Do you fully understand how it is supposed to operate (or, can you acquire operating manuals or the expertise of others to provide those specifications)?

 

[dogwood8488]

Looking more like that is the only option.

I think we have enough documentation to reprogram it.

 

[dogwood8488]

Thanks for all the replies. The backup file has been found and problem has been resolved.

Thanks Again