Rev 1.0
1/27/14
25
25
Reference Guide
Interfaces
Figure 18. 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
the AT Commands Interface Guide at
http://www.usr.com/support/3500
for more
information regarding AT Commands.
For more information on how to use the RS232 serial link to communicate with the
modem, refer to section 3.1.2.1 RS232 Serial Link Connection.
3.1.2.3.
Autobauding Mode
The autobauding mode allows the modem 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 the AT Commands Interface Guide at
http://www.usr.com/support/3500
for more information.
3.1.2.4.
Serial Port Auto Shut Down Feature
The RS232 serial link can be shut down when there is no activity between the DTE
and the modem. 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 the AT Commands Interface Guide at
http://www.usr.com/support/3500
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 modem.
