# Dynamic OPC tag properies

**URL:** <https://forum.inductiveautomation.com/t/dynamic-opc-tag-properies/72808>\
**Category:** Ignition\
**Tags:** perspective\
**Created:** [April 24, 2023, 6:49am UTC](https://forum.inductiveautomation.com/t/dynamic-opc-tag-properies/72808 "2023-04-24T06:49:14Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![siim\_suitslepp](https://avatars.discourse-cdn.com/v4/letter/s/e9bcb4/32.png) [@siim\_suitslepp](https://forum.inductiveautomation.com/u/siim_suitslepp)\
**Post date:** [April 24, 2023, 6:49am UTC](https://forum.inductiveautomation.com/t/dynamic-opc-tag-properies/72808/1 "2023-04-24T06:49:14Z")

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Hi,

I am trying to find a way to make dynamically changing "Engineering Limit High" for a tag, what would be the possibilities?

I have a OPC tag that is linearly growing (total energy register) and i have some data quality problems with sometimes saving a value of only 3000 units higher to DB. So i would like to make a dynamic tag property which will always be higher then for example this weeks start "total energy" + 1000 units.

Any ideas, or is it even possible? I am new to the community

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<div class="post-metadata">

**Author:** ![kyler.kamyszek](https://avatars.discourse-cdn.com/v4/letter/k/a4c791/32.png) [@kyler.kamyszek](https://forum.inductiveautomation.com/u/kyler.kamyszek)\
**Post date:** [April 24, 2023, 3:21pm UTC](https://forum.inductiveautomation.com/t/dynamic-opc-tag-properies/72808/2 "2023-04-24T15:21:35Z")

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You can use a script to write to the engHigh property of the tag using writeBlocking.

One way is you could have a SQL tag or name query getting the DB value. Then onChange event of the tag, write to your engHigh property.

```auto
system.tag.writeBlocking(['your/tag.engHigh'], [DB+3000])

```