Binding

Dynamic Binding vs Static Binding (wrt BACnet MS/TP devices)

On MS/TP, devices 0-127 are "Master" and 128-254 are "Slave". Master devices do token passing, and can Tx when some other node (normally the router) has sent them a message expecting a reply (DER, DNER, Test etc) OR when they have the Token. They can be discovered by broadcasting a Who-Is and observing the resulting I-Ams and recording their NN:MAC details for further use.. (Dynamic Binding)

Slave devices are NOT included in the token passing loop, and can ONLY Tx when some other node (normally the router) has sent them a message expecting a reply (DER, DNER, Test etc).

This means slave devices can never broadcast, therefore never broadcast an I-Am and are therefore not discoverable.

That means, you either have to know its BACnetAddress (NN,MAC) _in advance_ and enter those parameters in your BACnet "A"-side device, (Static Binding) or "probe" for them by reading e.g. Model_Name for each device, MAC address-by-MAC address.