I looked through the bacnet4j code and understand that if the server wants to read some object values stored on a field panel. It will send a ReadProperty request with src IP, dst IP and target object ID. The FP will reply with object list stored on its own memory, or send another request to its connected physical devices for polling.
However, the field panel may connect to multiple physical devices at a time and it uses BACnet MS/TP connection. (I guess this part is also included in the code stack). If multiple physical devices have the same object ID (e.g analog input #1), how does the field panel differentiate these object values from different physical devices? (I haven't been able to find relative code from the BACnet4J stack)
Does anyone know about this? Thanks!