Start with YABE to understand BACnet browsing. Then, if you need more realism, move to CAS Simulator’s free tier. For automation or embedded work, compile the BACnet Stack.
Use a free BACnet client to verify:
Several options are available, each with its own strengths: free bacnet ip device simulator
This review covers the three best free BACnet IP simulators, judged on ease of use, protocol compliance, simulation scale, and real-world utility. Start with YABE to understand BACnet browsing
Developers and power users comfortable with C and command-line interfaces. if you need more realism