Serial Interface Control Commands - CalAmp 819-GPRS series User Manual

Serial Interface Control Commands

The AT Commands described in this section allow the external application to determine various
settings related to the modems's serial interface.
Table 9.5: Serial Interface Control Commands
Command Description
Flow control:
0 - Disable flow control
1 - XON/XOFF software flow control
2 - Only CTS by DCE (TA)
AT\Q
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.
Set circuit Data Carrier Detect (DCD) function mode:
AT&C 0 - DCD line is always ON
1 - DCD line is ON in the presence of data carrier only
Set circuit Data Terminal Ready (DTR) function mode:
0 - TA ignores status of DTR.
1 - ON->OFF on DTR: Change to command mode while retaining the connected
AT&D
call.
2 - ON->OFF on DTR: Disconnect data call, change to command mode. During
state DTR = OFF auto-answer is off.
Set circuit Data Set Ready (DSR) function mode:
0 - DSR line is always ON
AT&S
1 - TA in command mode: DSR is OFF.
Enable command echo:
ATE 0 - Echo mode off
1 - Echo mode on
Serial Interface Character Framing:
=5,1 7 bits, even parity, 1 stop bit
=5,0 7 bits, odd parity, 1 stop bit
AT+ICF =2,1 8 bits, even parity, 1 stop bit
=3
=2,0 8 bits, odd parity, 1 stop bit
=1
Set Flow Control separately for data directions:
AT+IFC=<TEflowcontrol>, <TAflowcontrol>
TEflowcontrol:
0 - none
1 - XON/XOFF, terminate flow control in the Cellular Engine
2 - RTS line
AT+IFC
3 - XON/XOFF, evaluate flow control in the Cellular Engine and pass it through
(over the air) to the opposite TE
TAflowcontrol:
0 - none
1 - XON/XOFF
2 - CTS line
TA in data mode: DSR is ON.
8 bits, no parity, 1 stop bit
8 bits, no parity, 2 stop bits
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