AT Command Reference Guide for EDGE Wireless ... - wless.ru

Chapter 4 – Serial Interface Control Commands
Chapter 4. Serial Interface Control
Commands
The AT Commands described in this chapter allow the external application to determine various settings related to
the Multi-Tech wireless modem’s serial interface.
4.1 AT\Q Flow Control
Exec Command Syntax: AT\Q[]
Response:
OK
If RTS/CTS flow control is not supported by interface and is 2 or 3:
ERROR
Parameter Description:
0 Disable flow control. Default.
1 XON/XOFF software flow control
2 Only CTS by DCE (TA)
3 RTS/CTS hardware flow control
Recommended for the following procedures: incoming or outgoing data calls, fax calls, MUX mode.
Often, the initialization routine of Fax programs includes enabling RTS/CTS handshake, eliminating the need
to issue AT\Q3 once again.
Notes:
• When using XON/XOFF flow control (AT\Q1) in online mode, +++ should not be used while the data transmission
is paused with XOFF. Before entering the command mode with +++ the paused transmission should be resumed
using the XON character.
• Flow Control can be set by also using AT+IFC.
4.2 AT&C Set Circuit Data Carrier Detect (DCD)
Function Mode
Description:
Exec Command Syntax: AT&C[value]
Response:
OK
The AT&C command determines how the state of circuit 109 (DCD) relates to the
detection of received line signal from the distant end.
Parameter Description:
0 DCD line is always ON. Default.
1 DCD line is ON in the presence of data carrier only.
4.3 AT&D Set Circuit Data Terminal Ready (DTR)
Function Mode
Description:
The AT&D determines how the TA responds when circuit 108/2 (DTR) is changed from
ON to OFF during data mode.
Exec Command Syntax: AT&D[]
Response:
OK
Parameter Description:
0 TA ignores status of DTR. Default.
1 ON->OFF on DTR: Change to command mode while retaining the connected call.
2 ON->OFF on DTR: Disconnect data call, change to command mode. During state DTR = OFF auto-answer
is off.
Multi-Tech Systems, Inc. AT Commands for EDGE Modems (S000371B) 51