FullDuplex
Atypicalfull-duplexmultidropbusarchitectureinvolvesamaster-slave
protocol.Onlyonedevice,themaster,cancontrolaccesstothebus.All
otherdevicesareslaves.Slavedevicesmustwaitforthemastertogive
themaccesstothebus.Inatypicalfull-duplexsystem,onetransmission
lineconnectsthebusmastertransmittertoalloftheslavereceivers.A
secondtransmissionlineconnectsalloftheslavetransmitterstothebus
masterreceiver.Becauseeachtransmissionlinehastwoseparatewires,
afull-duplexsystemisoftenreferredtoasafour-wiresystem.The
masterusesfour-wiremode,andtheslavesusetwo-wiremode.The
followingfigureshowsatypicalfull-duplexsystem.
TypicalFull-DuplexSystem