Building QFreeOpcUaPlugin and QOpen62541Plugin plugins Qt 5.10

Bolonat

When I try to build a plugin QFreeOpcUaPlugin, I get a set of errors:
undefined reference to OpcUa::UaClient::GetNode(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&) const' undefined reference to OpcUa::Node::Node(OpcUa::Node const&)'
undefined reference to OpcUa::NodeId::NodeId()' undefined reference to OpcUa::Node::GetId() const'
undefined reference to OpcUa::Node::GetChildren() const' undefined reference to OpcUa::Node::GetId() const'
.........
I do not understand what I need to add, what is missing.

SGaist

The libraries from the backend you want to use. i.e.: open62541 or FreeOpcUa.

Bolonat

Now I got open62541_backend.dll, open62541_backendd.dll and libs in mingw53_32\plugins\opcua. But when I try to to compile example - project "accontrol" I got an error: E:\PROJECTS\accontrol\accontroltest.cpp:54: QtOpcUa/QOpcUaMonitoredValue: No such file or directory.
QOpcUaMonitoredValue class is missing in the source qtopcua-dev... Any ideas, please...

SGaist

Base on this commit, I'd say the example hasn't been update yet.

N3ff3

This post is deleted!

N3ff3

Hi guays,

I am at the same staep as you. I have done the steps qmake, mingw32-make, mingw32-make install.
And then I have the same problem with the open62541 and freeopcua.

My question is now, how do you get the open62541_backend.dll, open62541_backendd.dll and libs?

Many thanks in advance!

Greetings

SGaist

Hi,

AFAIK, build the corresponding project.

fmeerkoetter

@SGaist You are right. The API is currently settling down. There will be a Tech Preview in Qt 5.11. The examples you currently find on the dev branch are outdated. New examples are in the pipeline. You can find the first here: https://codereview.qt-project.org/#/c/216519/

fmeerkoetter

@N3ff3 please have a look at this article:
https://blog.basyskom.com/2018/want-to-give-qt-opcua-a-try/

You should go with the open62541 backend. Open62541 is the more complete implementation and has a much more active community.

Note that open62541 will release their 0.3 version in the next few weeks. We plan to use this release in the Tech Preview in Qt 5.11.

N3ff3

@fmeerkoetter
thank you very much for the information and the link.

Now I am testing the QtOpcUa. For this I use the Softing OPC UA .net Demo Server. The Problem is, that I can't connect to the server. I get this error message:

error/client	No suitable UserTokenPolicy found for the possible endpoints

After reading the docs of QtOpcUa, I can't find anything about the Policy.

Is there anything which I can use?

Best regards
N3ff3

paulholloway

@fmeerkoetter said in Building QFreeOpcUaPlugin and QOpen62541Plugin plugins Qt 5.10:

@N3ff3 please have a look at this article:
https://blog.basyskom.com/2018/want-to-give-qt-opcua-a-try/ https://cheapessaywriter.net/

You should go with the open62541 backend. Open62541 is the more complete implementation and has a much more active community.

Note that open62541 will release their 0.3 version in the next few weeks. We plan to use this release in the Tech Preview in Qt 5.11.

I read that open62541 is the most stable and feature complete open source backend presently in Qt OPC UA so you won't experience any difficulties.