OPC Item Path

Is it possible to use a variable (string, concat etc. ) in place of the opc item path similar to what is utilized for the UDT tags? If not, can it be implemented for those folks - pre UDT tags? Thanks

Have you tried using the same syntax for placing a UDT parameter in the OPC Server box?


I think he’s saying that he’s not using UDTs.

In that case, no, there’s no way to make it dynamic. Even with UDTs it’s not dynamic, in that parameters can’t be modified at runtime, only during config.

The idea of being able to dynamically direct tags to different OPC addresses comes up from time to time, but not very frequently. I can imagine it would be useful for things like recipe systems and systems with a lot of similar machines, but I’m afraid it would lead to more complexity and difficulty troubleshooting.

Anyhow, to sum up: not a horrible idea, but unlikely to get added all too soon.


Wasn’t thinking of implementing the address dynamically. It was just to speed up the replication of sites. So it would be used only in the initial run time. Tried using the find/replace but it doesn’t enable you to change individual characters within the string. i.e. FEP 35.r11. Just want to replace the 35 to a different address. Seem like the only way to do a bulk replacement, on 60 tags within a folder, is to dump and modify the csv. I’m I missing something and the find/replace can replace individual characters?

No, you’re right. We’d need to have some sort of regexp matching find/replace in order to do what you’re describing.