# Help with B&R Redundant System (X20CP3684) – Modbus\_TCP\_Any and OPC UA Cluster IP Issues - AS version 6.1.1.14

**URL:** <https://community.br-automation.com/t/help-with-b-r-redundant-system-x20cp3684-modbus-tcp-any-and-opc-ua-cluster-ip-issues-as-version-6-1-1-14/8861>\
**Category:** B&R Software & Runtime\
**Tags:** automation-studio, opc-ua, modbus\
**Created:** [October 31, 2025, 6:26am UTC](https://community.br-automation.com/t/help-with-b-r-redundant-system-x20cp3684-modbus-tcp-any-and-opc-ua-cluster-ip-issues-as-version-6-1-1-14/8861 "2025-10-31T06:26:46Z")\
**Posts on this page:** 1\
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**Author:** ![tommi.piiparinen](https://dub1.discourse-cdn.com/brcommunity/user_avatar/community.br-automation.com/tommi.piiparinen/32/2183_2.png) [@tommi.piiparinen](https://community.br-automation.com/u/tommi.piiparinen)\
**Post date:** [November 7, 2025, 11:30am UTC](https://community.br-automation.com/t/help-with-b-r-redundant-system-x20cp3684-modbus-tcp-any-and-opc-ua-cluster-ip-issues-as-version-6-1-1-14/8861/2 "2025-11-07T11:30:49Z")

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1. The Modbus\_TCP\_Any is only executed on the active PLC, which is why the other one reports an error.

2. OPC UA server should be accessible through the cluster IP and should not need any specific configuration due to controller redundancy.

Can you access any other services on the PLCs through the cluster IP? System Diagnostics Manager for example?

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