# Redundant codesys controllers

**URL:** <https://forum.inductiveautomation.com/t/redundant-codesys-controllers/104898>\
**Category:** Ignition\
**Tags:** ignition81\
**Created:** [April 9, 2025, 2:51pm UTC](https://forum.inductiveautomation.com/t/redundant-codesys-controllers/104898 "2025-04-09T14:51:32Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![johannes.bo](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/johannes.bo/32/27628_2.png) [@johannes.bo](https://forum.inductiveautomation.com/u/johannes.bo)\
**Post date:** [April 9, 2025, 2:51pm UTC](https://forum.inductiveautomation.com/t/redundant-codesys-controllers/104898/1 "2025-04-09T14:51:33Z")

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Hi  
My setup is dual Wago controllers running Codesys in a redundant pair. One is active, one is passive and standby. I plan to use OPC UA as communication protocol.

Each controller is visible with its own IP address and OPC UA server. Each controller exposes its own status: active or passive over OPC UA. However controllers may switch redundant role at any given time. My task is to set up a mechanism to ensure all my tags are connected to the active controller at any given time.

I have found several suggestions how to ensure Ignition is pointing to the active controller.  
However I find each involving som overhead in engineering, maybe even performance. And due to added complexity often added risk follows..

Any suggestion or experience is appreciated 🙂  
-What NOT to do  
-Any best-practice?

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**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:** [April 9, 2025, 10:43pm UTC](https://forum.inductiveautomation.com/t/redundant-codesys-controllers/104898/2 "2025-04-09T22:43:41Z")

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Can you give us more details? You don't even mention what protocol you're using to connect to these.

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<div class="post-metadata">

**Author:** ![johannes.bo](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/johannes.bo/32/27628_2.png) [@johannes.bo](https://forum.inductiveautomation.com/u/johannes.bo)\
**Post date:** [April 10, 2025, 7:18am UTC](https://forum.inductiveautomation.com/t/redundant-codesys-controllers/104898/3 "2025-04-10T07:18:53Z")

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Sorry 😉  
My original approach was to use OPCUA between controller and Ignition