Specifications

Version C15. February 2013 Raveon Technologies Corporation
Company Confidential
14
4.3. RS232/EIA232 Serial I/O Connector
The RS232 9-pin serial I/O connector is a female 9-pin D-subminiature connector
having the following pins configuration. It is pinned out so that it may be plugged
directly into a computer or PC’s 9-pin COM port.
Front-view of DB-9 connector on modem (female)
Pin
Name
Dir
Function
Level / Specification
1
CD
out
Carrier detect
If enabled, indicates presence of carrier. Logical 0 (+
voltage on RS-232) means carrier is present. If disabled,
it is asserted (0) whenever the modem is operational, and
not in the configuration mode. It will be a 1 when the
modem is in the configuration mode.
2
RxD
out
Receive data
Data out of the modem.
3
TxD
in
Transmit data
or
IN2
Data into the modem.
Also used as digital input IN2 for exception reporting.
GND or floating for a 0, >3V for digital 1. If enabled for
digital inputs, the serial data entering this pin is ignored
(except in the command mode). Use the TRIGBITS
command to set which bits are used as inputs.
4
DTR
in
Data terminal
ready
or
IN0
Normally ignored by the RV-M7 modem. May control the
power-state of the modem in low-power mode if this
feature is enabled.
Also used as digital input IN0 for exception reporting.
GND or floating for a 0, >3V for digital 1. Use the
TRIGBITS command to set which bits are used as inputs.
5
GND
Ground
connection
Signal and power ground
6
DSR
out
Data Set
Ready
Normally is set to 0 when modem is powered on and
running. Modem sets to a 1 when in low-power mode.
7
RTS
in
Request to
send
or
IN1
Used to stop/start the flow of data coming out of the
modem TxD pin. 0 = OK to send, 1 = don’t send. Leave
disconnected if not used.
Also used as digital input IN1 for exception reporting.
GND or floating for a 0, >3V for digital 1. Use the
TRIGBITS command to set which bits are used as inputs.
8
CTS
out
Clear to send
Used to stop the flow of data going into the RxD pin from
the device connected to the RV-M7. 0 = OK to send, 1 =
don’t send. If the RV-M7 cannot accept more data, it will
negate this signal (set to a 1).
9
Power
In/out
DC power
(not ring
signal)
User may supply the DC power to the modem on this pin.
Note: RS-232 signals use positive and negative voltages to represent digital 1s and 0s. A positive voltage is a
0, and a negative voltage is a digital 1.
This pin-out allows it to be directly plugged into a computer’s 9-pin serial port using
a conventional 9-pin RS-232 serial cable. To connect it to a modem, or peripheral
that has a serial port, you will need a “null-modem” cable. See Appendix A for
more information on wiring a null-modem cable.