RS485 Four-Wire Multidrop Network
An RS485 network can also be connected in a four-wire mode. In a four-wire network it's
necessary that one node be a master node and all others be slaves. The network is connected
so that the master communicates to all slaves and all slaves communicate only with the master.
This has advantages in equipment that uses mixed protocol communications. Since the slave
nodes never listen to another slave's response to the master, a slave node cannot reply
incorrectly.
