Datasheet
ADM2484E
Rev. C | Page 15 of 16
TYPICAL APPLICATIONS
Figure 30 and Figure 31 show typical applications of the
ADM2484E in half-duplex and full-duplex RS-485 network
configurations. Up to 256 transceivers can be connected to the
RS-485 bus. To minimize reflections, the line must be terminated
at the receiving end in its characteristic impedance, and stub
lengths off the main line must be kept as short as possible. For
half-duplex operation, this means that both ends of the line must be
terminated, because either end can be the receiving end.
NOTES
1. R
T
IS EQUAL TO THE CHARACTERISTIC IMPEDANCE OF THE CABLE.
2. ISOLATION NOT SHOWN.
06984-028
ADM2484E
RxD DE TxD
A B Z Y
ADM2484E
RxD DE TxD
A B Z Y
ADM2484E
ADM2484E
A
B
Z
Y
A
B
Z
Y
R
T
R
D
R
D
R
D
R
D
R
T
RxD
DE
TxD
RxD
DE
TxD
MAXIMUM NUMBER OF TRANSCEIVERS ON BUS = 256
RE
RE
RE RE
Figure 30. ADM2484E Typical Half-Duplex RS-485 Network
06984-029
R
D
RxD
RE
TxD
DE
ADM2484E
ADM2484E
A
B
Z
Y
R
D
RxD TxDDE
A
B Z Y
RE
R
D
RxD
TxD
DE
ADM2484E
MASTER SLAVE
SLAVE
A
B
Z
Y
RE
MAXIMUM NUMBER OF NODES = 256
ADM2484E
R
D
RxD TxDDE
A B Z
Y
RE
SLAVE
NOTES
1. R
T
IS EQUAL TO THE CHARACTERISTIC IMPEDANCE OF THE CABLE.
R
T
R
T
Figure 31. ADM2484E Typical Full -Duplex RS-485 Network