Page
12
RS
‐
232/485
RF
Modem
Product
Manual
–
MAN0782
‐
02
RS-485 (2-wire) Operation
DIP Switch Settings & Pin Signals
Figure
2.6.
Figure
2.7.
RS
‐
485
(2
‐
wire)
Half
‐
Duplex
Pins
used
on
the
female
RS
‐
232
(DB
‐
9)
DIP
Switch
Settings
Serial
Connector
Figure
2.8.
RS
‐
485
(2
‐
wire)
with
Termination
(optional)
Termination
is
the
120
Ω
resistor
between
T+
and
T
‐
.
DIP
Switch
settings
are
read
and
applied
only
while
powering
‐
on.
Note: Refer to Figures 2.15 and 2.16 for RJ-45 connector pin designations used in
RS-485/422
environments.
Table
2.2.
RS
‐
485
(2
‐
wire
half
‐
duplex)
Signals
and
their
implementations
on
the
RS
‐
232/485
RF
Modem
DB-9 Pin
RS-485 Name
Description
Implementation
2
T/R- (TRA)
Negative Data Line
Transmit serial data to and from the
RS-232/485 RF Modem
5 GND Ground
Signal
Ground
8
T/R+ (TRB)
Positive Data Line
Transmit serial data to and from the
RS-232/485 RF Modem
9 PWR
Power
Optional power input that is connected internally
to the front power connector
1, 3, 4, 6, 7
not used
Wiring Diagram: RS-485 (2-wire) Half-Duplex
Figure
2.9.
RS
‐
232/485
RF
Modem
in
an
RS
‐
485
(2
‐
wire)
half
‐
duplex
environment