[Announce] node-red-contrib-opc-da

After almost 5 months of development we finally released the first version of the OPC-DA Node :partying_face::partying_face:.
This node was created by Smart-Tech as part of the ST-One project.
At the moment it is only possible to read OPC tags, and it works pretty similar to the other nodes like Siemens S7, Allen Bradley/Rockwell Ethernet IP and Allen Bradley PCCC

Feedback and example projects are very welcome.


I'm testing it on my Windows 10 system reading tags from a Windows 7 machine with Kepware OPC Server. There are some kinks. The configuration page setting the CLSID and ProgID will accept the manually keyed entries, but when you go back to look at it after you've saved it, they are blank. :unamused:

Thanks, we will have a look on that.
By the way, can you post here what is the default Kepware OPC Server CLSID, so that we can add this option too.

Well done guys!
Dare I ask, would this node work for us users running node-red on Raspberry Pis?

I know at one time there were limitations to using OPC-DA on Linux machines.

Greetings, thank your for your report.

Which version of this node are you running? This bug was supposed to be fixed already.

Yes, the idea is to allow the use of OPC-DA on any machine running Node-RED. Please give it a try and feel free to report to us with any bug or suggestions you might have.

Judging from the port layout on their DIN mounted device, I suspect it just might...

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This is the older version. There is also V6, But I don't have that yet. I googled V5 to find that string.

Yes, by definition OPC-DA is a WINDOWS thing. It's because of DCOM and that is Windows.
OPC-UA, (Unified Architecture) does not rely on DCOM, it uses Certificates. That's what makes it possible for Linux to use OPC-UA.

You are right, but you can now run our OPC-DA node on Linux because, before implementing the node-red-contrib-opc-da, we had to implement the node-dcom, that allow us to communicate through DCOM in any system that supports NodeJS.
OPC-DA is no longer a "Windows Only" thing now :grinning:

OK, Things are getting better at a much faster pace! Kudos to you guys for compatibility for us old tech guys.

you Smart-Tech guys are awesome.:heart_eyes:

When should we expect to see OPC-DA Out?


This we cannot promise in a short term.
This protocol development was sponsored by one of our Customers here in Brazil and he is interested in the reading process only.
The "out" node is not even in the road map at the moment, so the only way is to wait for the community to help us, which is very welcome since it's an open source project.

Well OK then. :sob:

Boa tarde, Tiago, teria algum guia de como usar este node? Baixei aqui, porem apenas adicionou um node mesmo do pacote...

Olá Willian, vou responder em português e em inglês, porém acho melhor mantermos a comunicação em somente em inglês, pois assim mantemos a comunidade integrada, e caso alguém tenha a mesma dúvida no futuro, consiga facilmente encontrar a resposta aqui. O guia de uso do nó está na página que postei no inicio desse tópico: node-red-contrib-opc-da.
Basciamente o que você precisa fazer é configurar o endereço IP e credenciais da máquina que possui OPC-DA e em seguida clicar em "Test and get Items" para escolher as variáveis a serem coletadas.

Hi Willian, I'll answer your question in Portuguese and in English, but I strongly recommend you to use English only in this forum, so that in case someone has the same question in the future, it will be much easier to find the answer here.
The User guide is posted in the link that I mentioned in the beginning of this topic: node-red-contrib-opc-da.
Basically you have to configure the IP address and the credentials of the OPC-DA machine and then click on "Test and get Items" to see the variables.


Okay, Thankyou, It will help me!! I will put this in english now. Have a good day Tiago :slight_smile:

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Hello I am having trouble using it.

Can anyone knows what is my issue with my config?
I am running it on Windows 10 OS, with lates Nodejs version.

Hi guys,

I am facing an issue and I could not solve it.

I am currently using the OPC DA node with RSLInx and it works fine. But after few hours the node status changes from online to unknown and it stops communicating .

If I press "Restart Flows" or "Deploy" it starts to communicate again.

Have you seen that problem?

Can you specify what is your environment (windows versions, node-red version, node version...) and also your flow?

Hi Tiago,

It's a Ubuntu 18.04, Node-red V1.0.4 running under Docker.

OPD DA node version 1.0.3.

My flow is quite simple, it is a OPC DA node which reads from an OPC DA Server and stores its value into a variable. This variable is uploadad to influxDB every 10 seconds.

Do you need the .json?