# Expression tags not updating

**URL:** <https://forum.inductiveautomation.com/t/expression-tags-not-updating/80160>\
**Category:** General Discussion\
**Created:** [October 6, 2023, 9:29pm UTC](https://forum.inductiveautomation.com/t/expression-tags-not-updating/80160 "2023-10-06T21:29:35Z")\
**Posts on this page:** 6\
**Page:** 1

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**Author:** ![IcedMocha12](https://avatars.discourse-cdn.com/v4/letter/i/82dd89/32.png) [@IcedMocha12](https://forum.inductiveautomation.com/u/IcedMocha12)\
**Post date:** [October 6, 2023, 9:29pm UTC](https://forum.inductiveautomation.com/t/expression-tags-not-updating/80160/1 "2023-10-06T21:29:35Z")

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Hi All,

I'm currently having trouble with Expression tags. These are the settings that I currently have:

 ![1](https://us1.discourse-cdn.com/inductiveautomation/original/3X/6/3/6359de52cbf234d0270494ff7b24449c0d604bd3.png)  
The tag in the expression updates pretty fast, however the expression tag itself updates very slowly. I've also tried changing the Execution Mode to 'Event Driven' but the rate at which it updates is still slow.

Any help would be appreciated!

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**Author:** ![Kevin.Herron](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/kevin.herron/32/7259_2.png) [@Kevin.Herron](https://forum.inductiveautomation.com/u/Kevin.Herron)\
**Post date:** [October 6, 2023, 9:31pm UTC](https://forum.inductiveautomation.com/t/expression-tags-not-updating/80160/2 "2023-10-06T21:31:49Z")

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Can you get a thread dump from the Gateway and upload it here?

[https://docs.inductiveautomation.com/display/DOC81/Diagnostics+-+Threads#DiagnosticsThreads-IndividualThreads](https://docs.inductiveautomation.com/display/DOC81/Diagnostics+-+Threads#DiagnosticsThreads-IndividualThreads)

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<div class="post-metadata">

**Author:** ![IcedMocha12](https://avatars.discourse-cdn.com/v4/letter/i/82dd89/32.png) [@IcedMocha12](https://forum.inductiveautomation.com/u/IcedMocha12)\
**Post date:** [October 6, 2023, 9:39pm UTC](https://forum.inductiveautomation.com/t/expression-tags-not-updating/80160/3 "2023-10-06T21:39:56Z")

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Thanks Kevin,

Here's the downloaded thread dump  
[Ignition\_thread\_dump20231006-163336.json](https://forum.inductiveautomation.com/uploads/short-url/lXDiWXOP5CM8lm0IzeH8SyCUmIM.json) (632.9 KB)

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<div class="post-metadata">

**Author:** ![Kevin.Herron](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/kevin.herron/32/7259_2.png) [@Kevin.Herron](https://forum.inductiveautomation.com/u/Kevin.Herron)\
**Post date:** [October 6, 2023, 11:14pm UTC](https://forum.inductiveautomation.com/t/expression-tags-not-updating/80160/4 "2023-10-06T23:14:05Z")

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Expressions execute in a limited size thread pool, and it looks like all of your expressions are busy executing Python scripting that you've invoked via `runScript`. These need to be used sparingly and execute quickly so they don't affect other parts of the system like this.

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<div class="post-metadata">

**Author:** ![IcedMocha12](https://avatars.discourse-cdn.com/v4/letter/i/82dd89/32.png) [@IcedMocha12](https://forum.inductiveautomation.com/u/IcedMocha12)\
**Post date:** [October 9, 2023, 7:10pm UTC](https://forum.inductiveautomation.com/t/expression-tags-not-updating/80160/5 "2023-10-09T19:10:33Z")

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Thanks for the feedback Kevin.  
Is there a way to increased the size of the thread pool? I have another project that uses the exact same scripts, but don't run into this issue.

I disabled the UDTs that used runScript in the expression, however the updates were still slow.

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<div class="post-metadata">

**Author:** ![Transistor](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/transistor/32/3380_2.png) [@Transistor](https://forum.inductiveautomation.com/u/Transistor)\
**Post date:** [October 9, 2023, 8:12pm UTC](https://forum.inductiveautomation.com/t/expression-tags-not-updating/80160/6 "2023-10-09T20:12:32Z")

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There's no need for an expression in the example you've posted.  
`Expression: -1 * {[.]34_5 kVAR raw}`  
You're just multiplying by -1.

Use the scaling feature instead.

```auto
Value Source: OPC
etc.
Scale mode: Linear
Raw Low: 0.0
Raw High: 100.0
Scaled Low: 0.0
Scaled High: -100.0

```