Changes to SLC program on power-up

Hi guys,

I saw an interesting thing happen today on two SLC 5/04's I was working on. I had to make minor online changes to three rungs of code, as directed by an offsite vendor. He sent me the code and I copied the changes. I saved the file and tested the changes. However, the power to the panel and SLC had to be cycled (while I was still online). When power came back up, I was taken offline from the controller and told that the online program had changed. I went online with the old file (before the changes) and saw that the changes I had made were gone. I repeated this on another panel and saw the samw thing.

Anyone seen anything like this before? Is the SLC loading a program from somewhere on power-up? If so, where from and hopw do I modify that program? (The big cheeses have been accusing me of not saving the file properly, I need some ammo to fight back!)

Thanks.

The SLC probably has an EEPROM with the 'Load On Power Up' bit set. After you have made your changes you will have to save to the EEPROM so that THIS program is the one loaded on power up.

excellent, thank you