Page
10
RS
‐
232/485
RF
Modem
Product
Manual
–
MAN0782
‐
02
2.
Interfacing
Protocols
The RS-232/485 RF Modem supports the following interfacing protocols:
•
RS-232
•
RS-485 (2-wire) Half-Duplex
•
RS-485 (4-wire) and RS-422
RS-232 Operation
DIP Switch Settings & Pin Signals
Figure
2.1.
Figure
2.2.
RS
‐
232
DIP
Switch
Settings
Pins
used
on
the
female
RS
‐
232
(DB
‐
9)
Serial
Connector
DIP
Switch
settings
are
read
and
applied
only
while
powering
‐
on.
Table
2.1.
RS
‐
232
Signals
and
their
implementations
on
the
RS
‐
232/485
RF
Modem
(Low
‐
asserted
signals
are
distinguished
by
horizontal
line
over
pin
name.)
DB-9 Pin
RS-232
Name
Module
Name*
Description
Implementation
1 DCD GPO2 /
RX LED
Data-Carrier-Detect
Connected to DSR (pin6)
2
RXD
DO
Received Data
Serial data exiting the RF Modem (to host)
3
TXD
DI
Transmitted Data
Serial data entering into the RF modem (from host)
4
DTR
GPI2 / SLEEP Data-Terminal-Ready
Can enable POWER-DOWN on the RF Modem
5 GND - Ground
Signal
Ground
6 DSR GPO2 /
RX LED
Data-Set-Ready
Connected to DCD (pin1)
7
/ CMD
GPI1 /
/
CMD
Request-to-Send
Provides
flow control or
enables “Command Mode” on the RF Modem
8
GPO1 /
/
RS-485 TX EN
Clear-to-Send Provides
flow control
9 RI - Ring
Indicator
Optional power input that is connected internally to the
positive lead of the front power connector
*
Inside
the
RS
‐
232/485
RF
Modem
is
an
OEM
RF
Module.
The
names
in
this
column
refer
to
the
pin
signals
of
the
embedded
module.
RS
‐
232/485
Commands
[p32]
used
to
configure
pin
behaviors
are
named
according
to
the
pins
of
the
module,
not
the
RS
‐
232
connection.