# Tag Change Script in 8.3 **URL:** \ **Category:** Ignition\ **Tags:** ignition83\ **Created:** [November 26, 2025, 6:37pm UTC](https://forum.inductiveautomation.com/t/tag-change-script-in-8-3/112462 "2025-11-26T18:37:16Z")\ **Posts on this page:** 5\ **Page:** 1
**Author:** ![SBL\_MC](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/sbl_mc/32/56813_2.png) [@SBL\_MC](https://forum.inductiveautomation.com/u/SBL_MC)\ **Post date:** [November 26, 2025, 6:37pm UTC](https://forum.inductiveautomation.com/t/tag-change-script-in-8-3/112462/1 "2025-11-26T18:37:16Z")
It’s well known that Tag Change Scripts defined _on the tag itself_ can sometimes miss events and fail to execute reliably. Using a Gateway Tag Change Script has generally been the bullet-proof alternative. Has this behavior improved in Ignition 8.3? We often need to synchronize values from OPC Device A to OPC Device B through Ignition, which can result in a long list of Gateway Tag Change Scripts. Any improvements in reliability or alternative approaches would be appreciated. ---
**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:** [November 26, 2025, 6:38pm UTC](https://forum.inductiveautomation.com/t/tag-change-script-in-8-3/112462/2 "2025-11-26T18:38:53Z")
They don't "miss events". The queue can overflow when there are too many tag changes too quickly on a single tag, and there is a flag that indicates this happened. The behavior hasn't changed. ---
**Author:** ![SBL\_MC](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/sbl_mc/32/56813_2.png) [@SBL\_MC](https://forum.inductiveautomation.com/u/SBL_MC)\ **Post date:** [November 26, 2025, 6:41pm UTC](https://forum.inductiveautomation.com/t/tag-change-script-in-8-3/112462/3 "2025-11-26T18:41:37Z")
On a single tag? 🤔 It’s on the tags that change only once we see this happening. What is the name of this flag you mention? 😄 Sensor values etc, no worries - its ok the next second. ---
**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:** [November 26, 2025, 6:42pm UTC](https://forum.inductiveautomation.com/t/tag-change-script-in-8-3/112462/4 "2025-11-26T18:42:14Z")
> [@Difference Gateway Event vs Tag Event Scripts](https://forum.inductiveautomation.com/t/difference-gateway-event-vs-tag-event-scripts/63191/2): > > There are differences, but your conclusions are the opposite of what you might find. Both mechanisms will never miss a tag change event delivered by the tag system. A gateway event tag change script has an unbounded queue to hold and execute these change events. You won’t ever miss events, but it’s technically possible to run your memory up if your script execution blocks for a long time, or indefinitely, as events continue to queue up. Tag event scripts have a bounded queue, per-tag, size 5,… ---
**Author:** ![pturmel](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/pturmel/32/3295_2.png) [@pturmel](https://forum.inductiveautomation.com/u/pturmel)\ **Post date:** [November 26, 2025, 6:44pm UTC](https://forum.inductiveautomation.com/t/tag-change-script-in-8-3/112462/5 "2025-11-26T18:44:14Z")
> [@SBL\_MC](#): > > synchronize values from OPC Device A to OPC Device B through Ignition _Pssssst!_ See my [RePublish Tag Actor](https://www.automation-pros.com/toolkit/doc/actors.html#republish-action) in my Integration Toolkit. If you cannot use that, study this topic and the linked topics: > [@Java concurrent queue for tag change scripts](https://forum.inductiveautomation.com/t/java-concurrent-queue-for-tag-change-scripts/82044): > > Continuing the discussion from [[SOLVED] Are tag Value Changed scripts running asynchronously?](https://forum.inductiveautomation.com/t/solved-are-tag-value-changed-scripts-running-asynchronously/68704/5): We've got code in our standard library that I need to log a value change on a tag and then associate various data points with that value change. The value is located in a UDT, and because this is part of our "standard" library we use for our customers, the number of tags is variable and quite possibly numerous so having a gateway tag event script isn't feasible for this solution. I was reading up on …