Controllogix memory failure

[DaveBitByter 0]

Anyone out there experiencing memory failures with ControlLogix Processors? I have a system that has been in the field for over three years and has twice lost the program. The first occurance was about 6 months ago, then again last week. Both cases were corrected by e-mailing the program to a local A-B rep and having him visit the customers site for a download. The same customer has two other identical systems of the same age and neither has ever failed. These are all older 1756-L1 processors with 4.? firmware versions.

[Ken Roach 194]

There was a wierd memory blanking issue in firmware prior to 5.24 where the L1 could lose memory on power loss if there were unused motion tags and no memory module installed.   Fixed in firmware shortly thereafter... if that matches your system description then a simple flash upgrade might do the trick. Logix controllers (like many industrial controllers) will blank out their application program if it doesn't pass a memory checksum;  that can be caused by a real hardware memory fault, or noise-caused corruption of the memory system... and sometimes by actual errors in memory handling by the operating system, as in the above example. I'm surprised that the system ran for years before having such a problem;  I would have expected a firmware problem to emerge prior to that.   Noise could be introduced post-installation... and of course real hardware failure could be gradual. If you have the opportunity to upgrade the system to eliminate firmware as the culprit, I'd say do it.   Swapping out the L1 controller will eliminate hardware failure, leaving you only with induced noise as the potential culprit.

[tjice 0]

I had a similar problem with a system installed in the spring of '01. About 6 months later, I get all kinds of calls about the system not working. Since it was a coal handling system at a power plant, it was urgent (isn't it always?). The ControlLogix was a 5555 running firmware 7. It wasn't that difficult to fix, just download the program again and away we go. A call to the trusty AB tech support didn't really reveal what could have caused it since the program had already been reloaded. There was no motion control and it was a straight forward ladder logic program. We eventually flashed up to firmware v8 and haven't had any problems since. If this should happen to anyone again I would definitely reccomend trying to contact tech support or getting online (if even possible) to try to nail down an error code or something. The tech support rep told me that since the program had been reloaded, there was nothing he could find out. tj

[Guest Just a passing by guest]

This may be a bit of a late post, but to keep you guys freightened; even a ControlLogix 1756 running on FW11.30 still does. Happened to me a couple of times, in a couple of these FW 11.30 upgraded controllers, just a few months ago. AB-tech-supp told us this could happen when a power black-out of less then a second takes place, even with backup battery supplied. Cheers. MAW