RS Logix 5000 Instruction to search for a tag based on its name??

I have a RS Logix 5000 program that i feel was poorly structured and I'm trying to make the best of it.

There is a series of approx 40 tags with very similar names (MV_100, MV_101, MV_102, ect....), and with the exact same User Defined structure . The original programmer did not use an array for these tags. Each of the "MV" tags has a member called ".ID" that contains a decimal number that corresponds to the "MV" number (MV_101.ID = "101")

Now, I'd like to refer to these "MV" tags in my HMI without repeating the exact same screen over and over (I don't want to have to create a separate screen to control each individual "MV")

I'm trying to figure out a way to write back and forth, from a temp tag, to the "MV" tag for the purpose of writing to a "re-usable" HMI screen. I can't figure out how to write the HMI values back in to the PLC "MV" values because I can't figure out how to address the "MV" Tag with re-usable code.

I was thinking the answer might be to search for the tag based on the ".ID" value of it, but since the Tag name is different for each I was wondering if there was an instruction to reference a tag based on the string value of its name.

Any Ideas?

I'm not aware of such an instruction offhand.

wine_sparky said:

I can't figure out how to write the HMI values back in to the PLC "MV" values because I can't figure out how to address the "MV" Tag with re-usable code.

Click to expand...

If you don't mind having to re-load the screen each time you change which tag you are writing to, you could set the tag name as a parameter.

Alternately you could create a set of HMI inputs for each tag, then control their visibility.



This does indeed seem 'poorly structured' as you put it; seems an obvious place to use an array tag. Any reason you can't convert them to an array tag?

you could set the tag name as a parameter.

Click to expand...

I think this is what I'm trying to achieve. I just can't figure out how to do that.

On a second reading, I've gotten ahead of myself.

You specify 'RS Logix 5000' but what HMI do you have?

Automation Direct , C-More , EA-9

wine_sparky said:

Automation Direct , C-More , EA-9

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I could do it in a PVPlus, but unfortunately I don't have any experience with the C-More line. Hopefully someone who does can chime in with a solution.

If you change your MV tag to alias an array that would give you the option to search for the correct .ID

MV_100 alias for Array[0] and so on.

If you change your MV tag to alias an array that would give you the option to search for the correct .ID

MV_100 alias for Array[0] and so on.

Click to expand...

Great Idea! Thanks for that....

Sweet (cf. my second .sig line below ...'))!