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- "The requested OPC Data Access technology 'Com' is not supported"
"The requested OPC Data Access technology 'Com' is not supported"
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Thanks again for your support.
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Using the standalone installer is recommended anyway, but not for the reason you gave. OPC-DA (COM-based) *is* supported in the NuGet package. What is not supported in the NuGet package is COM development (as opposed to .NET development) - that means tools like VB6, VBScript, C/C++, PHP, Python, VBA (in Excel), Delphi, PowerBuilder etc. That's not your case, you are doing .NET apparently. So NuGet is OK in general, but NuGet gives you just the assemblies. The standalone installer also has examples, tools etc.
Best regards
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I'll try that tomorrow if I don't hear from you before then.
Thanks again for your assistance.
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Which .NET runtime and version is your project targeting, and what type of project is it (e.g. a class library, console app, Web app, Web service, etc.).
If you are targeting .NET Standard (class library) or .NET Core (app), then the behavior is as expected, because OPC DA (COM-based) is not supported: see opclabs.doc-that.com/files/onlinedocs/QuickOpc/Latest/User%2...l#Development%20Platforms.html
Best regards
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I'm sorry, I'm not at that machine at the moment, but the version should be the latest: I just pulled the Nuget package on Friday morning.
I don't think it is relevant, but just in case, I'll mention that after pulling the QuickOPC Nuget package, the code built but threw an exception at runtime creating the EasyDAClient instance because it couldn't find System.ServiceModel.Primitives.dll. I found that as a separate Nuget package, and after adding that, I could create the EasyDAClient instance. I assume that is as expected.
Thanks for your assistance.
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Have you set some instance or properties on the EasyDAClient class? In other words, is the snippet about the only part in your test that does something related to QuickOPC, or is there more?
Also, which version are using please?
Best regards
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I am trying to connect to a Kepware OPC server. I am using this snippet:
EasyDAClient client = new EasyDAClient();
var dav = client.ReadItem("localhost", "Kepware.KEPServerEX.V6", tag);
The ReadItem call throws:
NotSupportedException: The requested OPC Data Access technology 'Com' is not supported. Check the scheme "opcda" in server URL string "opcda://localhost/Kepware.KEPServerEX.V6".
+ The client method called was 'ReadMultipleItems'.
I have tried searching the documentation and this forum for this exception, but I haven't had any luck. Can you suggest what I may have done wrong? The URL shown in the exception is exactly the URL I am using successfully in ClientAce, so I am sure the server is there.
Thanks,
Jeff
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- Forum
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- QuickOPC-UA in .NET
- Reading, Writing, Subscriptions
- "The requested OPC Data Access technology 'Com' is not supported"