# Best Way to Script from Tag History NOT using Vision

**URL:** <https://forum.inductiveautomation.com/t/best-way-to-script-from-tag-history-not-using-vision/97095>\
**Category:** Ignition\
**Tags:** scripting, vision\
**Created:** [October 10, 2024, 5:01pm UTC](https://forum.inductiveautomation.com/t/best-way-to-script-from-tag-history-not-using-vision/97095 "2024-10-10T17:01:25Z")\
**Posts on this page:** 1\
**Showing post:** 34

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**Author:** ![lrose](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/lrose/32/62724_2.png) [@lrose](https://forum.inductiveautomation.com/u/lrose)\
**Post date:** [October 11, 2024, 7:43pm UTC](https://forum.inductiveautomation.com/t/best-way-to-script-from-tag-history-not-using-vision/97095/34 "2024-10-11T19:43:28Z")

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> [@Chris\_Bingham](#):
>
> with (my) most-notable thread

While the ~~thread pool~~ event queue size per tag is of note, the one that makes me consider value change events a last option is this one:

> [@Tag Value Change Scripts: Are They Run Asynchronously?](https://forum.inductiveautomation.com/t/tag-value-change-scripts-are-they-run-asynchronously/53749/9):
>
> Yes, there’s also a thread pool of size 3 that is shared between all tag event executions. This really only matters in the case you have a lot of slow to execute scripts, as @pturmel mentioned. Sometimes it’s okay to increase this pool size, but more often it means you’ve done something wrong and should rethink your approach.

So, not only is there a ~~thread pool~~ event que per tag, but all tag event executions are also in a limited thread pool. This means that only 3 threads can be executing at one time. If you litter your tags with value change scripts it isn't hard at all to hit this limit, and then the chance that you run into the ~~pool~~ queue size per tag only increases.

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