WA_DEV_FEX20_UGD_002
Rev 002
April 26, 2010
42
Fastrack Xtend User Guide
Interfaces
Figure 12.
V24 Serial Link Implementation for a 2-wire UART
The CT105/RTS and the CT106/CTS signals are not used in this configuration. Configure the AT
command
AT+IFC=0,0
to disable the flow control function. Refer to document [7] Firmware 7.4a
Commands Manual (Sierra Wireless Software Suite 2.31)/Firmware 7.4 AT Commands Manual
(Sierra Wireless Software Suite 2.30) for more information regarding AT Commands.
For more information on how to use the RS232 serial link to communicate with the Fastrack Xtend,
refer to section 5.1.2.1 RS232 Serial Link Connection.
5.1.2.2.
Autobauding Mode
The autobauding mode allows the Fastrack Xtend to detect the baud rate used by the DTE connected
to the RS232 serial link. The autobauding mode is controlled by AT commands. Refer to document [7]
Firmware 7.4a
AT Commands Manual (Sierra Wireless Software Suite 2.31)/Firmware 7.4 AT
Commands Manual (Sierra Wireless Software Suite 2.30) for more information.
5.1.2.3.
Serial Port Auto Shut Down Feature
The RS232 serial link can be shut down when there is no activity between the DTE and the Fastrack
Xtend. This can help improve the power consumption performance.
The Serial Port Auto Shut Down feature is controlled by the AT command
AT+WASR
. Enter:
AT+WASR=1
to enter the serial port auto shut down mode
AT+WASR=0
to exit the serial port auto shut down mode
Refer to document [7] Firmware 7.4a
AT Commands Manual (Sierra Wireless Software Suite
2.31)/Firmware 7.4 AT Commands Manual (Sierra Wireless Software Suite 2.30) for more information
on AT commands.
Caution:
GPIO24 is reserved for serial port auto shut down feature. It is prohibited for customer use. Improper
access to GPIO24 by customers may lead to unexpected behavior on serial port performance.
It is prohibited to use the serial port auto shut down feature when the CT108-2/DTR is not used in the
application. Otherwise, there will be data lost from the DTE side to the Fastrack Xtend.