# OPC-UA-Client payload is NULL

**URL:** <https://discourse.nodered.org/t/opc-ua-client-payload-is-null/44801>\
**Category:** Industrial\
**Created:** [27 April 2021 12:12 UTC](https://discourse.nodered.org/t/opc-ua-client-payload-is-null/44801 "2021-04-27T12:12:54Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![SRmag](https://avatars.discourse-cdn.com/v4/letter/s/9dc877/32.png) [@SRmag](https://discourse.nodered.org/u/SRmag)\
**Post date:** [27 April 2021 12:12 UTC](https://discourse.nodered.org/t/opc-ua-client-payload-is-null/44801/1 "2021-04-27T12:12:55Z")

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Hello everybody,  
I want to access the Siemens MyMachine OPC-UA Server. The connection works, but I didn't get any data in the payload, its always Null. I used UaExpert to get the NodeID and inserted it to the OPC-Item. I don't know why it's Null, because my UaExpert has a Value.

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**Author:** ![mikakaraila](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/mikakaraila/32/37496_2.png) [@mikakaraila](https://discourse.nodered.org/u/mikakaraila)\
**Post date:** [28 April 2021 04:45 UTC](https://discourse.nodered.org/t/opc-ua-client-payload-is-null/44801/2 "2021-04-28T04:45:00Z")

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Did you notice error message: Message types are not matching

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**Author:** ![SRmag](https://avatars.discourse-cdn.com/v4/letter/s/9dc877/32.png) [@SRmag](https://discourse.nodered.org/u/SRmag)\
**Post date:** [28 April 2021 05:59 UTC](https://discourse.nodered.org/t/opc-ua-client-payload-is-null/44801/3 "2021-04-28T05:59:14Z")

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Yes, but as you can see in the UaExpert datatype is UInt16 and this is what I have choosen in the OPC-Item-Type. Could it be that my NodeId is wrong?

I tried with different NodeIds but I always get the same error message.

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<div class="post-metadata">

**Author:** ![SRmag](https://avatars.discourse-cdn.com/v4/letter/s/9dc877/32.png) [@SRmag](https://discourse.nodered.org/u/SRmag)\
**Post date:** [28 April 2021 08:57 UTC](https://discourse.nodered.org/t/opc-ua-client-payload-is-null/44801/4 "2021-04-28T08:57:06Z")

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I solved the Problem.

My OPC-UA Nodes didn't had the latest Version. I updated them and all works fine, but thanks for the fast answer.

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**Author:** ![system](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/1X/d073cd938eafa2e558d7c2cd59003b3ef4963033.png) [@system](https://discourse.nodered.org/u/system)\
**Post date:** [27 June 2021 08:57 UTC](https://discourse.nodered.org/t/opc-ua-client-payload-is-null/44801/5 "2021-06-27T08:57:26Z")

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