Control Logix changes overnight?

Has anyone seen this before?
I downloaded the program last night and they ran production all night. Came in this morning and went to go online, and it wants to do an upload. Try to do an upload and the software locks up and the HMI's loose connection. Kill the locked up logix 5000 and the HMI's come back. Just no way to get online. The file I last downloaded was cleaned using the LGX export/import method per AB web site for a corrupted file. Looks like the only way I can get online again will be to download it again. This is the fourth time this week I am having to download it.

I have a case started with tech support but they say they wont help me until I upgrade the firmware to 20.18. But we have 5 other PLC's running 20.011 with no problems at all.

PLC 1756-L72
Logix version 20.01
Logix firmware 20.011
Program was converted from a PLC5, cleaned up and IO remapped.
Has a separate EN2T to communicate with 18 PF700 (RIO adapters 20COMMR changed to 20COMME), 1 PF525 and 6 Flex IO AENTR adapters each with 3 IO cards.
Thanks, Jack.

Was the controller faulted when you tried to connect to it ?

Do you have an SD card installed ? Could a power cycle have caused the controller to re-load a program from the SD card ?

I'm not going to say it's impossible for a ControlLogix program to "change overnight". The world is big. It contains things like the platypus, haggis, and Newt Gingrich. Very few things are so improbable as to be impossible.

It's more likely to me that there's something else going on with buffers or messages or HMI functions that are causing the controller to incorrectly claim that the program checksum has changed and require an upload.

If RA Tech Support thinks one or more of those issues could be affecting this controller and wants a baseline release of firmware before they'll continue to support troubleshooting, I'd say you should plan a firmware upgrade. I don't expect 20.011 -> 20.018 to cause any incompatibilities with the RSLogix 5000 software or your HMI.

The processors sometimes can get confused (very, very rarely), it happened to me some while ago.

The only way to overcome the issue was to re-download the program.

http://www.plctalk.net/qanda/showthread.php?t=97457

Steve

I figured out the changing problem. Turns out when you export/import any formulas like a + b * c will have spaces between them when offline. You download it and the Plc takes the spaces out. You don't realize it has, go offline and of course it doesn't says it's changed. Try to go back online and now it wants to upload because this program has about 300 formulas in it so it can't just correlat them.

Jax, how did you figure that one out?

Now to sidetrack a moment...

Ken Roach said:

I'm not going to say it's impossible for a ControlLogix program to "change overnight". The world is big. It contains things like the platypus, haggis, and Newt Gingrich. Very few things are so improbable as to be impossible.

Click to expand...

This is the best thing I've read in a long time, Ken. Can I shamelessly use it?

I finally had time to do a compare. And every rung with a formula was flagged as changed.

Ah. Gotcha. For some reason I was thinking that the compare function wasn't that sophisticated. Of course, I'm probably thinking of some other software package entirely. I think the more stuff I shove into my head, the more stuff falls out!