OPC DA Client or Gateway

Hi, does anyone know a way to get data from a OPC DA Server. Or does someone know another software as a Gateway OPC DA to UA or to OPC UA ? I need to get Data from a OPC DA to the cloud.

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Two suggestions off top of my head (I'm certain there are many more)...

1 install a suite like kepware. It has an OPC DA client driver and is a pretty decent OPC UA server.

2 update your OPC DA to a new OPC server with UA support.

Question... What are the end device(s)?

The Enddevice is a B&R PLC, the OPC DA Server is talking by PVI (a B&R tool) to the PLC

I'm not familiar with B&R nor what model you are using. Some documents suggest the B&R has built in OPC UA (perhaps newer models)?.

Have you looked at the drivers available in any of the major OPC suites? I'm certain you will find one.

I will ask by B&R if there is a UA Version available.

Well, OPC DA is one of the most polemic protocols ever, specially nowadays, when people are trying to collect as much data as possible from their shop floors.
At the moment there is no free solution for such a protocol. We are just starting the development of a OPC-DA node (to work together with our product ST-One) but it will take at least 6 months until we have it done and available on NodeRED.
The goal is to have something similar as we have with the other libraries we developed in the past, like Siemens S7 and Ethernet/IP (for AllenBradley)


I remember I developed a plugin for Eventghost using the free OpenOPC. It is written in Python, cross-platform ready for OPC-DA and worked pretty well I remember. I would look into writing a service/script in Python using this and communicate with NR via MQTT, should not be too difficult. But that's me since I'm still happy writing a bit Python from time to time...


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I use B&R PLCs and Node-Red.

The PLC is capable of both OPC-DA and OPC-UA, or rather was.

Since I last updated the runtime, the OPC-DA option is no longer present in the configuration. Only the UA option. If you have access to the PLC program and can enable OPCUA, that will be by far better than using DA.

You did mention PVI, is this an ARwin installation? E.g, is this a B&R PC or PLC?

Hi Vinzenz,

I think you can only get OPC UA from B&R when it is enabled in the project in Automation Studio. They don’t seem to offer it as part of Automation Net where the PVI and OPC DA live.

You can use Softing Datafeed as an independent OPC UA server for B&R without needing the much dreaded B&R licence for PVI but it isn’t free either. I wonder how Softing bypasses the PVI licence requirement....

Also, we are about to write our own Python shell script to link OpenOpc with python OPC UA. Contact me if you want to know how that is going. I don’t know if we will be able to run this on the old Automation PC without impacting on their performance. We’ll see.


I think the B&R plc support a lot of protocols. Have you considered using the plc as a modbus master? Then you can use the Node Red Modbus node.

I haven`t tested it myselve, but I guess it could work.


It does work. Not as elegantly as OPCUA though.

One thought I just had, the OP may be in a position where he does not have access to the source code in the PLC to change the communications to OPCUA. In B&R land, you must have the source code in order to make changes as there is no "upload" button. Unless the original programmer opted to store the source code on the PLC.

Have you checked opc expert? It might be cheaper than an full opc da/ua server like kepware or matrikon. It`s ment to be installed on top of a da server to make it «look like» ua.


It is finally here: [Announce] node-red-contrib-opc-da :tada:

Did you try to connect with MX OPC Server 6.0 ?

I try it but always give me this message " 2147942405 - Unknown error!" :joy: