Anybody with experience using Node-RED to communicate with INGEAR AB OPC?

Hello… I’m trying to use a Groov EPIC PR-1 controller to import some data from a plating line installed by a 3rd party in my facility. The installer uses an Allen Bradley PLC (which I know essentially nothing about) and I have not been given access to the PLC or its code. The installer also uses a Windows application called Flextime in conjunction with the AB PLC.

I know that Flextime and the AB PLC are communicating through an OPC server running on the Windows server that Flextime runs on. I know that the OPC server is INGEAR Allen-Bradley OPC Server 4.0. I can bring up a client on the local PC and see the various analog and digital inputs and outputs on the server:

If I look at the OPC configuration in Flextime (which, again, I did not set up), I see the following:


With that configuration, Flextime can see the items from the OPC server:

The online manual for the OPC server software seems pretty limited.

Within Node-RED, I installed node-red-contrib-opc-da (v1.0.4). When I create a opc-da in node, I’m prompted to create a OPC Group and then within that I’m prompted to create a OPC Server. When I attempt to create a server and run “Test and get items”, I get an authentication error in the debug pane:

For the username and password, I used the Windows username and password for the PC. I got the ClsId from the Flextime OPC configuration (seen in the screenshot above). I tried the ClsID with and without the surrounding curly brackets seen in the screenshot without any change. I don’t really know what to enter for the domain, but “CORROTEC” is the workgroup listed on the Windows PC.

Any help with this would be greatly appreciated. I hate dealing with this kind of closed third party system, but I need to do what I can to extract data from the AB I/O devices.

Do you know if the OPC server is running under a user account or local system account? I think it has to run as a user account if you want a remote device to authenticate with it and go into the DCOM security settings and set some permissions there too - details are fuzzy as it has been a long time since I set something like that up. Opto22 has a guide for their OPC server that you might want to run through to get the general idea. Kepware does as well.

I would try omitting the domain since this sounds like a machine that is not part of a domain.

I would also strongly consider running Node-red on the machine that has the OPC Server on it, as then you don’t have to expose DCOM to the network and won’t have all the authentication issues that go along with it.

@Philip: I’m not sure how the service is running on the Windows machine. I tried running Node-RED there locally and essentially I just get an unknown error message. I actually talked to the developer from the company that installed the line for us, and he basically told me to stop trying. He said the OPC server is to facilitate communications between their systems and if I affect anything by trying to talk to it, I’ll void the warranty on the entire project. Oh well…