Figure 5–4
Typical RS–485 half duplex interface circuit
DI
DE
RO
RE
Transmitter
TX +
TX –
Receiver
RX +
RX –
DI
DE
RO
RE
100
Ω
100
Ω
Receiver Receiver
Receiver
Transmitter
Transmitter
Transmitter
TX +
RX +
RX –
DI
DE
RO
120
RE
DI
DE
RO
2E
Figure 5–5
Typical RS–485 full duplex interface circuit
Transmitter
TX +
TX –
Receiver
RX +
RX –
DI
DE
RO
RE
100
Ω
100
Ω
100
Ω
Receiver
RX +
RX –
RO
RE
Transmitter
Receiver
DI
DE
RO
RE
Transmitter
Receiver
DI
DE
RO
RE
Transmitter
TX –
TX +
DI
DE
100
Ω
59