Beckhoff STRUCT/UDT Configuration Issue


I have set up an OPC connection with a Beckhoff application and can successfully read the tag values. The issue i’m having though is that they are displayed as one value, meaning separate entities in the UDT are not displayed when dropped down:

I would expect/hope on expanding the tag, i’d see an entity for bAlarmActive, bAxisOK, and bAxisReady. Below is my configuration on the Beckhoff side which I am thinking is the issue, but can’t find an example online as to how to separate the sub-items.


Do you see the struct member tags when you try to browse underneath the parent tag in the OPC Browser?

I can:

When I click import on just the top level structure, it does not import any of the sub items in, if i click import of all of the items, it breaks the structure and just imports everything at one level:

You may need to select one or the other. The top level in this case is a tag with a structured value, not an object or folder, so it’s only going to import that if you select it. It’s far less load on the PLC when you read the structure as a whole instead of its individual member tags.

If you want the individual tags then make a folder and bring them into that folder.

If you do stick with pulling in the structured tag, there’s a strategy described in this post
(and elsewhere) for pulling members into their own tags if needed.

Thank you!

Hi Kevin,

I just wanted to confirm I’m doing it the reccomended way,

I made a UDT of derived tags and pass in a reference to my physical OPC tag via a parameter:

I then utilize the read or write expression based on need and to keep it modular, I reference the tag name of the child component: