# Sync OPC Tag from different PLC

**URL:** <https://forum.inductiveautomation.com/t/sync-opc-tag-from-different-plc/36867>\
**Category:** Ignition\
**Tags:** ignition80\
**Created:** [July 20, 2020, 3:49pm UTC](https://forum.inductiveautomation.com/t/sync-opc-tag-from-different-plc/36867 "2020-07-20T15:49:06Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![ltraverso](https://avatars.discourse-cdn.com/v4/letter/l/e56c9b/32.png) [@ltraverso](https://forum.inductiveautomation.com/u/ltraverso)\
**Post date:** [July 20, 2020, 3:49pm UTC](https://forum.inductiveautomation.com/t/sync-opc-tag-from-different-plc/36867/1 "2020-07-20T15:49:06Z")

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Hello everybody,  
I’ve two integer OPC TAG from two different PLC (example PLC1 and PLC2) .  
I would like when PLC1 change write PLC2 with same value.  
I tried with “Tag event script -\> value changed” and works fine but, if I’ve PLC2 off, PLC1 change and then PLC2 on the value on PLC2 is old. In this way are not syncronized until PLC1 change.  
How can I do to solve this problem ?  
Thank you very much

Luca

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**Author:** ![JordanCClark](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/jordancclark/32/83362_2.png) [@JordanCClark](https://forum.inductiveautomation.com/u/JordanCClark)\
**Post date:** [July 20, 2020, 3:52pm UTC](https://forum.inductiveautomation.com/t/sync-opc-tag-from-different-plc/36867/2 "2020-07-20T15:52:53Z")

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Two ideas for you.

- Use a transaction group.
- Use a gateway timer script.

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<div class="post-metadata">

**Author:** ![ltraverso](https://avatars.discourse-cdn.com/v4/letter/l/e56c9b/32.png) [@ltraverso](https://forum.inductiveautomation.com/u/ltraverso)\
**Post date:** [July 20, 2020, 4:00pm UTC](https://forum.inductiveautomation.com/t/sync-opc-tag-from-different-plc/36867/3 "2020-07-20T16:00:08Z")

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Thank you Jordan,  
I will try with a transaction group.

Thanks  
Luca