# Binding in Tag Editor - Expression not possible?

**URL:** <https://forum.inductiveautomation.com/t/binding-in-tag-editor-expression-not-possible/106533>\
**Category:** Ignition\
**Tags:** perspective\
**Created:** [May 21, 2025, 8:43pm UTC](https://forum.inductiveautomation.com/t/binding-in-tag-editor-expression-not-possible/106533 "2025-05-21T20:43:40Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![arun1](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/arun1/32/79753_2.png) [@arun1](https://forum.inductiveautomation.com/u/arun1)\
**Post date:** [May 21, 2025, 8:43pm UTC](https://forum.inductiveautomation.com/t/binding-in-tag-editor-expression-not-possible/106533/1 "2025-05-21T20:43:40Z")

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I have tag (type UDT) with folders and standard tags inside those folders. I would like to bind the Alarm Eval Enabled property to another tag but there does not seem to be a way to use regular Expressions to connect to another tag. I would like to connect this property to something like this:  
({[.]../../J2\_MP206/PLC\_Inputs/XS} && {[.]../../J2\_MP206/PC\_Controls/Formula} = 1)

 ![image](https://us1.discourse-cdn.com/inductiveautomation/original/3X/5/7/571d9698079d9cbd339a94f338699c7712828618.png)

But if I go into those alarms and pick an alarm, then I can bind the Enabled property to the same expression. My question is why doesn't Ignition allow Expression on the properties outside but allows Expression in the properties inside the alarm?

 ![image](https://us1.discourse-cdn.com/inductiveautomation/original/3X/0/8/08a10363abf6cbdd263d8bb636b9dd2c43adc332.png)

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<div class="post-metadata">

**Author:** ![nminchin](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/nminchin/32/6911_2.png) [@nminchin](https://forum.inductiveautomation.com/u/nminchin)\
**Post date:** [May 22, 2025, 2:52am UTC](https://forum.inductiveautomation.com/t/binding-in-tag-editor-expression-not-possible/106533/2 "2025-05-22T02:52:21Z")

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You'll need to write these changes with a script instead. I'm not entirely sure why some props can be bound to tags while other's can't; I presume it's to do with performance impacts?

You can add a valueChange script on the reference tag which writes to that tag's `AlarmEvalEnabled` prop