I have implemented RS485 master - slave protocol using address recognition. It seems OK with me. If a slave is waiting for it's own address in a transmitted frame from the master to multiple slaves by just polling received bytes, it can also false detect it in the the frame. So each new frame begins with bit 9 set, all slaves get an interrupt, they compare own address to first received byte and if is equal, slave serial receive mode is changed by clearing SM2 and slave receives the whole frame. When transmiting binary data in the frame there is a danger of false address recognitions if not using this mode. For secure data transmision, CRC16 is appended to each frame.