HUAWEI MG323 GSM M2M Module
AT Command Interface Specification Commands for Serial Port Control
Issue 02 (2010-11-23) Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd. 37
4 Commands for Serial Port Control
This chapter describes the AT commands for controlling the serial ports of the module.

4.1 AT\Q - Command for Enabling Software or Hardware

Flow Control

The AT\Q command sets the flow control mode.
Execution
command
AT\Q[<n>]
Function Sets the flow control mode.
Response z In case of successful execution: <CR><LF>OK<CR><LF>
z In case of not supporting RTS/CTS when n = 2 or 3:
<CR><LF>ERROR<CR><LF>
Note:
z Hardware flow control is recommended, especially for the data service and multiplexing.
z In the case of CSD data service, hardware flow control must be adopted.
Parameter description
<n>: integer, which is not saved upon power failure; AT\Q is equivalent to AT\Q0.
z 0 (default value): disables flow control.
z 1: XON/XOFF software flow control.
z 2: Only CTS by DCE(TA).
z 3: RTS/CTS hardware flow control.

4.2 AT&C - Command for Setting the DCD Usage State

The AT&C command sets the relation between the status of the DCD line and signal
detection of the remote receiving line.