Sorry to my bad english.
So i use a automate with MERVIS software and i use a Bacnet server to have my variable in my IHM (weintek panel pc with Easybuilder Pro).
So all i make is good and work but i'm not happy to EasyBuilder pro and i want make my own HMI. I decide to make my application with QT in C++.
But i'm physicien at the begining so learn little bit by little bit( i have base of python,c++, structur text). I know nothing about how build a bacnet client and do you have idea where can i find some simple exemple to communicate with my PLC because i find nothing and i need to learn and make this to my project.
So i have my PLC, link in ethernet to my PC where i make my hmi. In the future i want put this application in PANEL PC tactil work in window and link to my PLC with MERVIS software.
If I'm clear on the question, you could checkout the 'BACnet Stack' project source code or even the 'VTS' source code too - for a C/C++ (language) reference.
Otherwise YABE is a good project in C# (language), but there's also a BACnet NuGet package available for C# too - along with the mechanics that underpin the YABE tool.