Tag Names in ControlLogix

Does any one know if there is a way to get the "TAG NAME" in code in a Control Logix Processor?

Example:
In AOI, you pass a tag. The item then gets worked on in the AOI. It would sure be nice if we could somehow ascertain the name of the ACTUAL tag we are doing that work on?

You could then easily create an AOI that "built up" a String for display on an HMI just by supplying it the tag and not have to retype, create typos, and time consuming changes when some I/O points move...

Not sure I follow what you are asking here....

Are you referring exclusively to the AOI? The instruction has a tag associated with it that you specify. The AOI potentially has Input and Output parameters that are all part of that AOI tag you specified.

Can you provide a more specific example?

OG

He wants to create an AOI which receives a tag and builds a string which contains not only the value from the tag but also the actual tag name for subsequent display.

Yes, that is exactly correct!! Get the string of the Tag name itself. I'm sure you can't but, I'd just thought I'd ask....

Nope, I know of no way to interrogate the tag to return the tag-name.

The only way I can think of doing anything like this is to make each tag you pass to the AOI a User-Defined tag that includes a STRING tag.

That way you can manually put the tag-name in the STRING.

If you go this route, you may want to consider creating your own STRING tag that only holds 40 characters instead of the standard 80, call it STRING40 or similar. (Because tag-names can be 40-chars max.)

Since, in ControlLogix, the full tagname exists within the PLC at runtime, a great '.tag' extension off the tag itself could just point to the memory storage for the tagname. Just a thought for future revisions.

daba said:

Nope, I know of no way to interrogate the tag to return the tag-name.

The only way I can think of doing anything like this is to make each tag you pass to the AOI a User-Defined tag that includes a STRING tag.

That way you can manually put the tag-name in the STRING.

If you go this route, you may want to consider creating your own STRING tag that only holds 40 characters instead of the standard 80, call it STRING40 or similar. (Because tag-names can be 40-chars max.)

Click to expand...

We have done something similar previously, every UDT had 2x string fields called Tagname & Description.
This was to circumvent the cumbersome compiler in FTME, and also to reduce the tag database size of the .mer file. It added the extra flexibilty of being able to change the description quite easily, without process interuption!! Was a must for those typos that seem to appear... But, I cannot remember if I left them at the default 80 or not, will need to check that for next time!

bernie_carlton said:

Since, in ControlLogix, the full tagname exists within the PLC at runtime, a great '.tag' extension off the tag itself could just point to the memory storage for the tagname. Just a thought for future revisions.

Click to expand...

Would be a good feature. Would then negate the need for copy/pasting in the database.
Is there a CLX improvements/requests thread somewhere...?

This post is 12 years old; but the only mention I've found online.

Has anything changed now up to v34?


Would be useful in the modern world. (Granted AB isn't exactly leading tech)