# Tag Update query **URL:** \ **Category:** Ignition\ **Created:** [November 3, 2025, 2:02pm UTC](https://forum.inductiveautomation.com/t/tag-update-query/111894 "2025-11-03T14:02:12Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![devaraj.v](https://avatars.discourse-cdn.com/v4/letter/d/ecccb3/32.png) [@devaraj.v](https://forum.inductiveautomation.com/u/devaraj.v)\ **Post date:** [November 3, 2025, 2:02pm UTC](https://forum.inductiveautomation.com/t/tag-update-query/111894/1 "2025-11-03T14:02:12Z")
I have two tags reading from the compact Logix PLC. According to plc program both tag will become high at a time ,but we have observed that one of the tag is updating with a delay which is causing an issue to execute the tag change script in client event. We have changed the tag group of one tag with 1000ms another tag to 50ms (subscribed), but still the 50ms tag is not updating properly. We have used 1000ms tag for tag change script event to trigger, and we are checking the status of 50ms tag inside the script ,but observe that the tag value is not updating some times. What could be the reason ? ---
**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:** [November 3, 2025, 2:06pm UTC](https://forum.inductiveautomation.com/t/tag-update-query/111894/2 "2025-11-03T14:06:26Z")
It might be helpful to post your code. Please see [Wiki - how to post code on this forum](https://forum.inductiveautomation.com/t/wiki-how-to-post-code-on-this-forum/77831). ---
**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 3, 2025, 2:15pm UTC](https://forum.inductiveautomation.com/t/tag-update-query/111894/3 "2025-11-03T14:15:08Z")
1. OPC does not provide any delivery order guarantees for any subscribed values 2. OPC Drivers cannot magically make subscriptions deliver at a given pace if a connection is overloaded. 50ms is overly optimistic in most applications. Have you looked at the driver's diagnostics page? You should screenshot it and show it here. If you have a trigger tag, after which you wish to collect related values, you should not make tags for those related values. Instead, read them with `system.opc.readValues()`, which ensures the ordering you appear to need. ---
**Author:** ![Nol](https://avatars.discourse-cdn.com/v4/letter/n/8e8cbc/32.png) [@Nol](https://forum.inductiveautomation.com/u/Nol)\ **Post date:** [November 5, 2025, 9:40pm UTC](https://forum.inductiveautomation.com/t/tag-update-query/111894/4 "2025-11-05T21:40:04Z")
Gateway / Status / Connections / Devices / The PLC connection What are the stats on your tag groups. Is it actually scanning at 50ms or are things overloaded and everything is scanning slower?