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9602 SBD Modem | Installation and User Manual
17
RS232 Specification
The 9602 SBD MODEM is provided with an RS232 serial port for data connection. The 9-pin D-type
(female) socket is wired DCE for connection to a standard PC with a 1:1 cable.
Physical Connection
The pin-out of the connector is described in the following table:
Pin
Signal
Direction
Description
1
DCD
Modem
PC
Data Carrier Detect (Driven ON at all times)
2
RXD
Modem
PC
Received Data
3
TXD
PC
Modem
Transmitted Data
4
DTR
PC
Modem
Date Terminal Ready
5
GND
Signal Ground (Common)
6
DSR
Modem
PC
Data Set Ready (CTS and DCD)
7
RTS
PC
Modem
Request to Send
8
CTS
PC
Modem
Clear to Send
9
RI
Modem
PC
Ring Indicator
RS232 Port Signal Support and Handshaking
The Serial data interface is used to both command the 9602 SBD MODEM and transfer user data
to and from the Transceiver. The 9602 SBD MODEM presents a 9-wire data port to the FA (Field
Application), where the interface is at RS232 levels. With respect to this interface, the 9602 SBD
MODEM behaves as a DCE (Data Communication Equipment), and the FA behaves as a DTE (Data
Terminal Equipment).
The terms “FA” and “DTE” are used interchangeably throughout this document; similarly for the term
“DCE” and modem.
Autobaud is not supported in 9602 SBD Modem. The baud rate can be set via the AT+IPR command.
The default rate is 19200 bps.
9-Wire and 3-Wire Operation
By default, the serial interface operates as a 9-wire connection. Table 9 describes each of the signals,
where “input” means an input to the 9602 SBD MODEM, and “output” means an output from the
9602 SBD Modem Transceiver.
RXD
- Active high data output [The DTE receives the data from the 9602 SBD MODEM].
TXD
- Active high data input [Data is transmitted from the DTE to the 9602 SBD MODEM].
GND
- 0V.
RTS
- Active low flow control input.
CTS
- Active low flow control output. RTS and CTS are used together to implement hardware
flow control when enabled with AT&K3.
