# Alarm in Array and Tag Group

**URL:** <https://forum.inductiveautomation.com/t/alarm-in-array-and-tag-group/116205>\
**Category:** Ignition\
**Created:** [June 30, 2026, 12:59pm UTC](https://forum.inductiveautomation.com/t/alarm-in-array-and-tag-group/116205 "2026-06-30T12:59:14Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![MaximePuntis](https://avatars.discourse-cdn.com/v4/letter/m/d78d45/32.png) [@MaximePuntis](https://forum.inductiveautomation.com/u/MaximePuntis)\
**Post date:** [June 30, 2026, 12:59pm UTC](https://forum.inductiveautomation.com/t/alarm-in-array-and-tag-group/116205/1 "2026-06-30T12:59:14Z")

</div>

I just discovered a bug. I use boolean arrays to report alarms, and the alarm text is linked to a string array. A quick detail: these two arrays are tags derived from a "Document"-type source in the PLC (S7-1500, communicating via OPC UA).

 ![Capture d'écran 2026-06-30 142614](https://us1.discourse-cdn.com/inductiveautomation/original/3X/5/f/5fac24df8c5aa0fe1d5050ee6e6a619d389a0ceb.png)

 ![Capture d'écran 2026-06-30 142624](https://us1.discourse-cdn.com/inductiveautomation/original/3X/9/0/9062708dc4712d67c156df760684951c526afeef.png)

 ![Capture d'écran 2026-06-30 142651](https://us1.discourse-cdn.com/inductiveautomation/original/3X/7/9/79829287fe3cd3e920bb629761cc14e0d0fdcd0f.png)

 ![image](https://us1.discourse-cdn.com/inductiveautomation/original/3X/a/2/a2181ea2f62a0d1e395182708f93677dafdedd5d.png)

However, every now and then, the alarm text no longer matches the correct index.

 ![image](https://us1.discourse-cdn.com/inductiveautomation/original/3X/d/8/d8296b0a0fd564b270d6d54cc808373121eede65.png)

Strangely enough, restarting the tag by clicking the "Restart Tag" button in the Designer fixes the issue.

 ![Capture d'écran 2026-06-30 142732](https://us1.discourse-cdn.com/inductiveautomation/original/3X/e/2/e2c60f1eb5ac719471b31eeae3f5b9b17ec26c4d.png)

 ![image](https://us1.discourse-cdn.com/inductiveautomation/original/3X/d/d/ddfbf9836db5a6179a0eaaffc73dce27f771b09c.png)

This phenomenon occurs when communication with the PLC is lost or when the PLC is reloaded.

 ![image](https://us1.discourse-cdn.com/inductiveautomation/original/3X/1/c/1c40f824b458b666fe69186819cd12ec97aed40a.png)

After analyzing the situation, I realized the issue stems from the fact that the source tag's "tag group" differs from that of the derived tags.

 ![Capture d'écran 2026-06-30 142532](https://us1.discourse-cdn.com/inductiveautomation/original/3X/d/3/d33027b8198bee50e69ff3a99581d831899aed28.png)

 ![Capture d'écran 2026-06-30 142542](https://us1.discourse-cdn.com/inductiveautomation/original/3X/3/1/3186967022f8a232b4148e09bd9e76e872fd186c.png)

If I move all the tags to the same tag group, the problem goes away! Like this one:

 ![Capture d'écran 2026-06-30 143908](https://us1.discourse-cdn.com/inductiveautomation/original/3X/1/4/149d7d01406a52bb6b6336e346d1603f8c3ac95d.png)

This allows me to resolve the issue. I am sharing my findings anyway because I know the Inductive Automation teams are responsive and attentive to developers. Plus, it might help someone else facing the same problem