ab-slc 500 trouble saving program


Thread Starter

Imran Nasir

Whenever there is power interruption SLC goes to default program and loses modified program, even internal battery is ok.


Dan Taylor - Logical Control Solutions

This sounds to me like you have an EEPROM in your processor that is programmed to load on power up. You must have your original program loaded in the EEPROM so that is why it gets reloaded. My suggestion is to download your modified program to the processor, then once it is loaded and you are on-line, go to the COMMS pull down menu to EEPROM and then click on Store to EEPROM. This should fix your problem.

Dan Taylor
Logical Control Solutions
[email protected]

Bob Niemeyer

It sounds like you may have proms in the proocesser and are loading from them when you shut off the power. Try removing the proms from the processer, and setting the switches in the processer to not load the proms at all. Then you
will just need to load the program from your laptop.
I got into this a while back because I had a 5/04 that kept dumping on very short power outages. The AB people have told me this is a safety measure built into the SLC's that will load a "default" blank program if it feels the memory
is corrupted. This is probably a smart thing.

The outages caused a power "blink" that was not enough time to cause a total re-load from EEPROM but enough to cause the memory checksum to be inaccurate.

Only way to solve this problem is good, clean power and a UPS if it's in a critical process.

PS... If it is doing this and it's not critical, follow the previous directions and load your program onto the EEPROM. Then, if it defaults you can cleanly cycle power (ie 5 seconds off) and restart. The correct program will load
successfully from EEPROM and the SLC will take off.

PSS According to AB, this is also often caused by problems with power on the backplane. If it's happening, make certain that you DO NOT have any other devices connected to the SLC power supply's "complmentary" terminals. The power
supplies brown out very easily and are not designed for much of a load. AB ususally recommends that you don't power anything from them, and the only thing I've successfully powered are AIC+ modules.