# UDT OPC ItemPath indirect Binding using Tag instead of Parameter

**URL:** <https://forum.inductiveautomation.com/t/udt-opc-itempath-indirect-binding-using-tag-instead-of-parameter/67534>\
**Category:** Ignition\
**Tags:** ignition81\
**Created:** [December 13, 2022, 3:13am UTC](https://forum.inductiveautomation.com/t/udt-opc-itempath-indirect-binding-using-tag-instead-of-parameter/67534 "2022-12-13T03:13:41Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![GregCavazos](https://avatars.discourse-cdn.com/v4/letter/g/ee7513/32.png) [@GregCavazos](https://forum.inductiveautomation.com/u/GregCavazos)\
**Post date:** [December 13, 2022, 3:13am UTC](https://forum.inductiveautomation.com/t/udt-opc-itempath-indirect-binding-using-tag-instead-of-parameter/67534/1 "2022-12-13T03:13:41Z")

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Hello,

I am trying do an indirect binding of the OPCItemPath of a OPC Tag inside a UDT, I can successfuly bind regular UDT parameters, but I havent been able to add an indirect bind of an internal tag in the mix.

Inside the same UDT there is an expression tag that gets populated with the correct data. All parameters get replaced correctly, except the tag.

Any ideas of what I may be doing wrong?

 ![image](https://us1.discourse-cdn.com/inductiveautomation/original/3X/1/6/1617fc7cdd51032603bc6c04378c99b88111ad09.png)

 ![image](https://us1.discourse-cdn.com/inductiveautomation/original/3X/4/e/4ecf17730eecdb5db2a414d46eabafdef736b947.png)

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**Author:** ![pturmel](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/pturmel/32/3295_2.png) [@pturmel](https://forum.inductiveautomation.com/u/pturmel)\
**Post date:** [December 13, 2022, 3:26am UTC](https://forum.inductiveautomation.com/t/udt-opc-itempath-indirect-binding-using-tag-instead-of-parameter/67534/2 "2022-12-13T03:26:00Z")

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It simply is not supported for property bindings in tags. Expression tags have full access to other tags. Tag properties are not expression tags themselves.

If you must, use a script on the peer tag that writes an override to the OPC Item Path of the target tag.

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<div class="post-metadata">

**Author:** ![GregCavazos](https://avatars.discourse-cdn.com/v4/letter/g/ee7513/32.png) [@GregCavazos](https://forum.inductiveautomation.com/u/GregCavazos)\
**Post date:** [December 13, 2022, 3:33am UTC](https://forum.inductiveautomation.com/t/udt-opc-itempath-indirect-binding-using-tag-instead-of-parameter/67534/3 "2022-12-13T03:33:06Z")

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> [@pturmel](#):
>
> It simply is not supported for property bindings in tags. Expression tags have full access to other tags. Tag properties are not expression tags themselves.

Oops, for some reason I was in the idea that I've seen that somewhere.

> [@pturmel](#):
>
> If you must, use a script on the peer tag that writes an override to the OPC Item Path of the target tag.

Is there a way to programmatically (script or expression tag) override parameters of a UDT tag?

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<div class="post-metadata">

**Author:** ![pturmel](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/pturmel/32/3295_2.png) [@pturmel](https://forum.inductiveautomation.com/u/pturmel)\
**Post date:** [December 13, 2022, 3:34am UTC](https://forum.inductiveautomation.com/t/udt-opc-itempath-indirect-binding-using-tag-instead-of-parameter/67534/4 "2022-12-13T03:34:24Z")

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For most, just write to the property. For some, use `system.tag.configure`.

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<div class="post-metadata">

**Author:** ![GregCavazos](https://avatars.discourse-cdn.com/v4/letter/g/ee7513/32.png) [@GregCavazos](https://forum.inductiveautomation.com/u/GregCavazos)\
**Post date:** [December 13, 2022, 3:43am UTC](https://forum.inductiveautomation.com/t/udt-opc-itempath-indirect-binding-using-tag-instead-of-parameter/67534/5 "2022-12-13T03:43:44Z")

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Thank you! @pturmel for the quick responses!

For now, I will create a new UDT Parameter that will be automatically get overwritten by the internal expression tag, seems to be working on my dev environment.