Weird RSLogix500 Problem, anyone else seen?

I do recall having somehow corrupted an instruction for lack of a better term...

I had to type in a new identical rung and then it was accepted and I could drill into the dialog boxes.

Greetings Mark ...

I've seen it do the trick shown below on a few occasions ... it seems to happen most often whenever the moon is full ...

.

I've seen this happen as well, it seems like it occurs when there are multiple people online with the processor making edits. Usually the other person making the edits still has a good copy of the program. Are you able to do an upload from the processor? Does that resolve the problem? If not, AFAIK doing a fresh download is the only way to fix it.

Ron, Yes the moon was full when it happened! And you picture was very like what we had, except the xio and the msg were in separate UNK instructions.

gitargr8, We did have multiple computers online doing various edits. I thought RA had improved from the PLC5 where you would get kicked off when someone else made an edit, but I guess it seems like they created another possible issue to look out for.

I had deleted the rungs before I realized what they were for, figuring they were some old code not used by CLX (BTR,BTW). When we started having problems due to the lack of messaging, I wrote new rungs and the problem went away (Thankfully CLX tags keep all the setup info and that part was easy to redo). After checking with the guy who wrote the messages originally I found his copy to be correct. We will just have to keep an eye out for this in the future when multiple people are online at the same time making changes for a startup.

thanks
Mark Snodgrass