RSLogix5000 - Tag Actively being read by one or more clients

I have set external access to None in both the properties dialog AND the Edit Tags view, and STILL "Tag is actively being read by one or more clients":mad:;)

What the heck is this? I'm relatively new to Rockwell, but this is nuts. The tag is an AOI datatype and I'm updating the AOI. Plenty of clients all over the plant read buggy data from this AOI at all times, and I need to address the bug in the code, so the clients read the CORRECT data. So i have to shut down all the clients? Who came up with that?

Additionally, the fact that AOIs can't be modified online in the first place boggles my mind. Why the heck does America prefer Rockwell again?
 
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My "workaround" was to move the contents of the new tags to the relevant pre-existing, un-delete-able;) old tags until I can download to the PLC again. Added another item to my downtime to-do list!
 
If anyone else is still having this problem, I found a solution where I did not have to download, or go offline. In the tag database I changed the tags "External Access" from Read/Write to None. I was then able to delete the tags.

Genius! 🍺
 
Workaround

I have set external access to None in both the properties dialog AND the Edit Tags view, and STILL "Tag is actively being read by one or more clients"


Was having the same issue. Found a workaround. In the edit tags menu, right click the tag. At the bottom I used the "set external access for..." to change it from none to read only. after that it finally let me delete the tag.


Hopefully that works for you.
 
That "set external acces..." is a newer feature in RSLogix/Studio, it wasn't around in 2011 at the time of the OP.

It is typical RA arrogance that they know what's best for you. Who's in charge of the work anyway, the Controls Engineer or a flipping HMI? A pop-up warning in Logix with an OK/Cancel should have been plenty sufficient. Other PLCs don't even give you that, you can delete whatever unused (in the PLC) tags you want. I fail to understand the perceived hazard, but then again I haven't done every possible application. Only about 30 years worth.

My quick-fix for this has always been, and it works regardless of Logix version, is to physically disconnect the network between the PLC and HMI and it removes the deleting restriction. This won't necessarily be acceptable for everyone's situation, but in my experience if you ask the operators most will say they can go without the HMI for a minute. You only need a few seconds for it to register that the client(s) is gone and you can get your tag deleting done and reconnect the cable(s) to get the HMI communicating again.
 
Additionally, the fact that AOIs can't be modified online in the first place boggles my mind. Why the heck does America prefer Rockwell again?


Which manufacturer's PLCs let you modify user defined function blocks (or AOIs) online? None I've use. I think the industry has, for the most part, assumed if you are dropping code in a function block to be used all over your code, that you've tested it enough that it should require minimal changes. And if a change is required, a download is expected at that point. Looking at it from the PLC side, since each use is instantiated it would make updating the online code and associated variables (and internal memory) OTF a lot more extensive than a typical online programming change. I generally build my AOI/UDFB code in a regular routine first until I have all the bugs worked out, then put it inside an AOI/UDFB.
 

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