# Iot Gateway Omnicore OPC ua subscribe issue after warmstart

**URL:** <https://tech-community.robotics.abb.com/t/iot-gateway-omnicore-opc-ua-subscribe-issue-after-warmstart/11738>\
**Category:** OmniCore\
**Tags:** omnicore, iot-gateway\
**Created:** [December 17, 2024, 12:25pm UTC](https://tech-community.robotics.abb.com/t/iot-gateway-omnicore-opc-ua-subscribe-issue-after-warmstart/11738 "2024-12-17T12:25:01Z")\
**Posts on this page:** 1\
**Page:** 1

<div class="post-metadata">

**Author:** ![Fanny](https://avatars.discourse-cdn.com/v4/letter/f/b38774/32.png) [@Fanny](https://tech-community.robotics.abb.com/u/Fanny)\
**Post date:** [December 17, 2024, 12:25pm UTC](https://tech-community.robotics.abb.com/t/iot-gateway-omnicore-opc-ua-subscribe-issue-after-warmstart/11738/1 "2024-12-17T12:25:01Z")

</div>

Hi!

Im running a RW 7.15.3 system with a OPC UA server running through IoT Gateway. I have an issue that the server is not triggering updates on my subscribed IO signal variables after a warmstart. There is some really weird issues that sometimes some of the signal subscription callbacks work, and after a restart/resubscribe of the OPC UA client application it works again. But sometimes I have to restart the whole OPC UA server in IoT gateway to make it work again. When I get it working, it works fine until another restart of the robot controller…  
Any ideas? I’m considering switching to PC SDK communication instead.