Chapter 3: AT Commands Reference
June 30, 2008 AT Commands Reference Manual 3-437
After the entering active session mode (G24 sent CONNECT to the terminal), the terminal can
perform one of the following:
If the terminal sends additional data, the G24 transmits another frame
If the terminal sends only <DLE><ETX> (a null frame), the G24 turns off the transmit
carrier and sends the CONNECT result code to the terminal
If five seconds elapses from the time the G24 reports the OK result code without any
additional data transmitted from the terminal, the G24 turns off the transmit carrier, returns to
command mode, and sends the ERROR result code to the terminal.
Note: MOD = 3 (Clause 2/V.21) rate 300 bps, is mandatory.
If the G24 detects a carrier after the FTH command, it sends a CONNECT to the terminal.
If not, it sends "NO CARRIER".
The following table shows the command modulation select codes.
Example
AT+FCLASS=1
OK
ATD035658584
CONNECT 19200
AT+FRH=3
CONNECT 19200
(Terminal sends TSI frame data, as described in ITU-T30 with terminating sequence)
CONNECT 19200 //The G24 detected the terminating sequence
(Terminal sends DCS frame data, as described in ITU-T30 with terminating sequence and drops the
carrier)
OK
Command Type Syntax Response/Action Remarks
Set FTH = <MOD>
(Send data stream
<DLE><ETX>)
CONNECT
OK
or:
NO CARRIER
The Set command causes the G24 to
transmit data framed in HDLC
protocol using the modulation mode
selected.
Table 3-288:Command Modulation Select Codes - Modulation Parameters
<MOD> Value Modulation Tra inTim e Rate (bit/s) Required
24 Rec. V.27 ter 2 400
48 Rec. V.27 ter 4 800
72 Rec. V.29 7 200
96 Rec. V.29 9 600