Redhawk II GSM Modem Users Guide
Draft: 10/30/00
12
Part Number: 07100020 version 00B
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All trademarks and copyrights are the property of Xircom, Inc.
Secondary Serial Control Interface (CTL)
This serial I/O interfaces (RS-232) that support auto baud capability from 300 bps to 19200
bps.
Connector:
RJ-11
Pin
Number
Signal
Name
Direction
Functionality
Voltage
Level
1
GPIO2_RJ
To/From CPE
General purpose I/O. Used as a general purpose input or output
line for monitoring or control of external devices. Requires
customized stack software to implement. Leave signals
disconnected if function is not used.
3 V
2
GPIO1_RJ
To/From CPE
General purpose I/O. Used as general a purpose input or output
line for monitoring or control of external devices. Requires
customized stack software to implement. Leave signals
disconnected if function is not used.
3 V
3
RX_D
From CPE
Receive Data 1. DTE Input signal. Secondary serial-interface
receive data signal. Used as a debug interface for test purposes.
Leave signal disconnected if function is not used.
5 V or
3 V
4
TX_D
To CPE
Transmit Data 1. DTE Output signal. Secondary serial-interface
transmit data signal. Used as a debug interface for test
purposes. Leave signal disconnected if function is not used.
3 V
5
GND _RJ
To CPE
Electrical power return for digital and analog grounds.
6
GPIO0_RJ
To/From CPE
General purpose I/O. Used as general a purpose input or output
line for monitoring or control of external devices. Requires
customized stack software to implement. Leave signals
disconnected if function is not used.
3 V
Table 4: Secondary Serial Connector Pin Out
NOTE: The maximum length for the Secondary Serial cable is 50 feet.
Voice interface (MIC/SPKR)
Uses an RJ-9 connector and provides differential microphone inputs and speaker outputs.