# How to connect OPC/UA nodes after disconnect in a reliable way?

**URL:** https://discourse.nodered.org/t/how-to-connect-opc-ua-nodes-after-disconnect-in-a-reliable-way/68410
**Category:** General
**Tags:** opcua
**Created:** [30 September 2022 05:38 UTC](https://discourse.nodered.org/t/how-to-connect-opc-ua-nodes-after-disconnect-in-a-reliable-way/68410 "2022-09-30T05:38:56Z")
**Posts on this page:** 3
**Page:** 1

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### Author: ![Gawan](https://avatars.discourse-cdn.com/v4/letter/g/e9c0ed/32.png) [@Gawan](https://discourse.nodered.org/u/Gawan)
#### Post date: [30 September 2022 05:38 UTC](https://discourse.nodered.org/t/how-to-connect-opc-ua-nodes-after-disconnect-in-a-reliable-way/68410/1 "2022-09-30T05:38:57Z")

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Hello,

we have started to use OpcUa together with Node-Red to establish machine to machine communication.

Now we are facing a problem after machine disconnects:

We do a regular (1/sec) READ on a Opc/Ua client to check for new data.  
It happens from time to time that a client goes offline for any reason or is not reachable via network.  
In this case the READ fails and the session gets lost until the client is back up again. As soon as it is online a new session is created automatically and the READ proceeds.

BUT ... if we do the same with a WRITE OPC/Ua Node it is not possible to reestablish the session after a disconnect.  
The session is in a failed state and so far we did not find out how to reset it.  
DISCONNECT or RECONNECT does not work as expected.  
The only think that helps is to redeploy the whole flow, but that has other negative side-effects.

Does anybody know how to handle this the right way ?  
We are of course willing to pay for professional support !

BR  
Gawan

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### Author: ![piwi447](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/piwi447/32/67335_2.png) [@piwi447](https://discourse.nodered.org/u/piwi447)
#### Post date: [30 September 2022 21:29 UTC](https://discourse.nodered.org/t/how-to-connect-opc-ua-nodes-after-disconnect-in-a-reliable-way/68410/2 "2022-09-30T21:29:41Z")

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Hello i had the same problem on my old nodered version, since i upgraded to nodered latest14 with latest OPC UA it seems working better.

 ![image](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/3X/3/7/37933677dacf9da089448cf1b43b6bf2e2d73128.png)  
 ![image](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/3X/e/c/ecf814cafd3e468f1f72f830dc61e14ad539d784.png)

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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: [29 November 2022 21:29 UTC](https://discourse.nodered.org/t/how-to-connect-opc-ua-nodes-after-disconnect-in-a-reliable-way/68410/3 "2022-11-29T21:29:49Z")

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