ADM2484E
TYPICAL APPLICATIONS
Figure 30 and Figure 3± show typical applications of the
ADM2484E in half-duplex and full-duplex RS-481 networꢀ
configurations. Up to 216 transceivers can be connected to the
RS-481 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 ꢀept 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.
V
MAXIMUM NUMBER OF TRANSCEIVERS ON BUS = 256
CC
ADM2484E
ADM2484E
A
B
A
B
R1
RxD
RxD
R
R
RE
DE
RE
R
R
T
T
DE
Z
Y
Z
Y
TxD
D
TxD
D
R2
A
B
Z
Y
A
B
Z
Y
R
R
D
D
ADM2484E
ADM2484E
RxD RE DE TxD
NOTES
RxD
DE TxD
RE
1. R IS EQUAL TO THE CHARACTERISTIC IMPEDANCE OF THE CABLE.
T
2. ISOLATION NOT SHOWN.
Figure 30. ADM2484E Typical Half-Duplex RS-485 Network
MAXIMUM NUMBER OF NODES = 256
V
T
DD
R1
MASTER
R
SLAVE
D
A
B
Z
Y
Z
RxD
RE
TxD
R
DE
V
DD
R1
R
R2
B
A
RE
DE
T
D
TxD
RxD
R
Y
R2
ADM2484E
ADM2484E
A
B
Z
Y
A
B
Z
Y
SLAVE
SLAVE
R
R
D
D
ADM2484E
ADM2484E
RxD RE DE TxD
RxD RE DE TxD
NOTES
1. R IS EQUAL TO THE CHARACTERISTIC IMPEDANCE OF THE CABLE.
T
Figure 31. ADM2484E Typical Full -Duplex RS-485 Network
Rev. 0 | Page 15 of 16
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