# Node-red-contrib-opcua, "event Node", what to fill in the field "root node"?

**URL:** <https://discourse.nodered.org/t/node-red-contrib-opcua-event-node-what-to-fill-in-the-field-root-node/60972>\
**Category:** General\
**Created:** [8 April 2022 10:09 UTC](https://discourse.nodered.org/t/node-red-contrib-opcua-event-node-what-to-fill-in-the-field-root-node/60972 "2022-04-08T10:09:35Z")\
**Posts on this page:** 1\
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**Author:** ![learnobyte](https://avatars.discourse-cdn.com/v4/letter/l/d6d6ee/32.png) [@learnobyte](https://discourse.nodered.org/u/learnobyte)\
**Post date:** [15 May 2022 05:51 UTC](https://discourse.nodered.org/t/node-red-contrib-opcua-event-node-what-to-fill-in-the-field-root-node/60972/2 "2022-05-15T05:51:44Z")

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> [@SIEMENS OPC UA Server crashes after starting flow in EVENT Mode](https://discourse.nodered.org/t/siemens-opc-ua-server-crashes-after-starting-flow-in-event-mode/46798):
>
> Hello, I'm trying to get Messages and Alarms of a Siemens OPC UA Server (SINUMERIK 840dsl). I've done this with a EVENT-Node of the "node-red-contrib-opcua" library. If I start my flow everything works well and I get my Messages and Alarms. But after this first start my OPC UA Server Crashes and is no longer reachable. I already tried to fix the Problem with the LocaleIds array in the ActivateSessionRequest Method, to send a ["en-us"] back instead of an empty array. But this also changes nothing…

pls, refer to this post, m also trying the same things. able to collect alarm and events in UA expert, got stuck in node-red.

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