# UDT Expression Tag Using OPC Tag Path Error

**URL:** <https://forum.inductiveautomation.com/t/udt-expression-tag-using-opc-tag-path-error/112823>\
**Category:** Ignition\
**Tags:** perspective\
**Created:** [December 15, 2025, 8:31pm UTC](https://forum.inductiveautomation.com/t/udt-expression-tag-using-opc-tag-path-error/112823 "2025-12-15T20:31:24Z")\
**Posts on this page:** 1\
**Showing post:** 7

<div class="post-metadata">

**Author:** ![ryan.white](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/ryan.white/32/73193_2.png) [@ryan.white](https://forum.inductiveautomation.com/u/ryan.white)\
**Post date:** [December 15, 2025, 8:58pm UTC](https://forum.inductiveautomation.com/t/udt-expression-tag-using-opc-tag-path-error/112823/7 "2025-12-15T20:58:06Z")

</div>

Please post code as preformatted text, it preserves whitespace and syntax highlighting, see [Wiki - how to post code on this forum](https://forum.inductiveautomation.com/t/wiki-how-to-post-code-on-this-forum/77831). You can edit your post by clicking the pencil icon in the bottom right.

To me it looks like your first `abs` is missing its ending enclosing paranthesis (adjusted for better readability):

```python
// Current Unbalance Formula
// Calculate Absolute Maximum Deviation of Phase Currents
(max(
	abs({[.]CurrA} - {[.]CurrAvg}),
	abs({[.]CurrB} - {[.]CurrAvg}),
	abs({[.]CurrC} - {[.]CurrAvg})
// Divide by Current Average Magnitude * 100 for %
) / {[.]CurrAvg}) * 100

```

---

_[View the full topic](https://forum.inductiveautomation.com/t/udt-expression-tag-using-opc-tag-path-error/112823)._