UNK instrutions

alexbeatle

Member
Join Date
Feb 2010
Location
San Francisco
Posts
188
Hello,

I'm seeing the UNK in my online version of the PLC code (see attached).

This has been written by someone else and shows normal on the other person's machine and the rung is executing properly. But for me it shows as the UNK.

Both machines have the same Logix Designer ver21.03.

Has anyone encountered these?

Thank you.

2019-01-16_11-00-46.png
 
I usually get UNK when I type the name of an instruction wrong. But since you said the logic was originally written by someone else and looks fine on their computer, I'm not sure what's going on. I would try to create a new project on your computer, then export/import routines from the other person's project into your project.
 
Had this as well on a project where 5 people were working on the same PLC online on a large program. On the PC of the person who did the online edit the code was shown fine, on some of the others the UNK's were shown. The PLC executed the code fine, but the people with the UNK's could no longer go online if they went offline because the program did not compile anymore on their PC.

This was on V24 with L73S.
 
Last edited:
Do a file save as .L5K and then open .L5K and resave as .ACD That should correct your file when that happens.
 
I usually type my rungs in manually, I get the unk’s if I put in an extra space. Any chance your regional settings are different, maybe controlligix is interpreting a character as a space?
 
Had this as well on a project where 5 people were working on the same PLC online on a large program. On the PC of the person who did the online edit the code was shown fine, on some of the others the UNK's were shown. The PLC executed the code fine, but the people with the UNK's could no longer go online if they went offline because the program did not compile anymore on their PC.

This was on V24 with L73S.

Had this scenario before.. I logged on the next day to the plc and it's program had slight changes from my colleague (logic only, no tags edited or created) corelation created this UNK instruction. Ended up doing a full upload from scratch and compared just because I was curious what caused the issues and it was just basic MOV and ADD instructions..
 
This has happened to me while others did edits or when RSLogix "experienced an error"
and crashed while I was editing. The online program is working OK, your computer just isn't interfacing with it properly to show you.

Going offline and doing an upload fixed it every time.
 
I just noticed that you are showing a line of code in edit mode. That could also be the someone entered it wrong - but since I see the XIC's and OTE (all legitimate instructions) I believe you just need to upload to see it right.
 
Hi,

Glad you got sorted but did you read the thread linked at post #10?

The steps you took are fine but you could also have more simply...

Saved a copy of the offline file (which now has the corrupted logic) just in case
Performed an upload to existing file (not new) selecting the original (or new copy) project file

An upload from the online controller will automatically correct the corrupted logic in the offline copy. You would not need to manually copy/paste the offending logic from a new uploaded file to the existing copy project.

Because I would usually have a couple of backup copies at any one time, I would normally just do a straight upload to the existing offline copy that I have open with UNK corruption - no saving an extra copy first. One step, logic recovered.

Regards,
George
 

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