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Cannot browse nodes on Red Lion OPC server through VPN

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17 May 2019 08:16 #7380 by support
I have found that the trial version I had in mind is only the OPC "Classic" Server. It looks like that Red Lion's OPC UA server runs only in the device, which I do not have access to.

We now have two options - one is the VPN you mentioned. The other is to collect the traces of the communication (the one that works - with the other tool; and the one which does not work) using Wireshark, and send them to us for analysis. WOuld you be willing to do that? (I can give further instructions then).

BTW, didn't you use some username/password in the other OPC UA client to open the connection? Sometimes the OPC server uses user authentication, but also allows unauthenticated access - falling back to a "minimal" mode where only limited functionality is available. That would explain the different results. If so, QuickOPC allows to specify the user credentials as well.

Best regards

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16 May 2019 13:58 #7375 by support
That would be an option, thank you.
It seems, however, that there is a trial version of the server for download. I will see if I can get it to work and reproduce the issue. Otherwise, we will proceed to the VPN option.

Give me some time. I will notify you here when I know more.

Best regards

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16 May 2019 13:02 #7374 by gtan14
I can get you VPN access to the server if that would help.

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16 May 2019 12:59 #7373 by gtan14
I tried changing it to ObjectsFolder but still nothing. There are nodes under Server and V1.
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16 May 2019 07:31 #7372 by support
In your code, you start the browsing from the "Server" object. But in the picture, either the Server object also has nothing under it, or it is just not expanded, I cannot tell. Therefore the comparison of the code and the picture is not telling anything useful.

For start, I would change UAObjectIds.Server to UAObjectIds.ObjectsFolder.

Best regards

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15 May 2019 15:50 #7371 by gtan14
Yes catch block is never reached, which leads me to believe I am connecting. Whenever I try to print out the size of the collection, it returns 0 though. The other application I am using is made by buro-allmendinger. Not really sure what it's called. I attached a screenshot of what I am looking at when browsing through the app
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15 May 2019 14:15 - 15 May 2019 14:16 #7369 by support
Hello.

I have some questions:

1. Are you saying that the code doe not go to the "catch" block (the Browse does not throw an exception), but it also doe snot print out any nodes?

2. Which "other application" is able to show the nodes? Can you post a screenshot?

Thank you
Last edit: 15 May 2019 14:16 by support.

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15 May 2019 14:09 #7368 by gtan14
I'm trying to browse nodes on a Red Lion OPC server. I'm using the exact code from the documentation, except I'm using my server address. It seems that I am connecting, however no nodes are being found. I know that the server is working correctly, since I can browse using another application. Has anyone else had problems browsing Red Lion OPC servers? This is the code I am using
UAEndpointDescriptor endpointDescriptor = new UAEndpointDescriptor("opc.tcp://192.168.3.66:4840");
 
            // Instantiate the client object
            var client = new EasyUAClient();
 
            // Obtain nodes under "Server" node
            UANodeElementCollection nodeElementCollection;
            try
            {
                nodeElementCollection = client.Browse(
                    endpointDescriptor,
                    UAObjectIds.Server,
                    new UABrowseParameters(UANodeClass.All, new[] { UAReferenceTypeIds.References }));
            }
            catch (UAException uaException)
            {
                Console.WriteLine("*** Failure: {0}", uaException.GetBaseException().Message);
                return;
            }
 
            Console.WriteLine(nodeElementCollection.Count);
 
            // Display results
            foreach (UANodeElement nodeElement in nodeElementCollection)
            {
                Console.WriteLine();
                Console.WriteLine("nodeElement.NodeId: {0}", nodeElement.NodeId);
                Console.WriteLine("nodeElement.DisplayName: {0}", nodeElement.DisplayName);
            }
 
            Console.ReadLine();

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