AT Commands Reference Manual - wireless netcontrol GmbH

Chapter 3: AT Commands Reference
After the entering active session mode (H24 sent CONNECT to the terminal), the terminal can
perform one of the following:
• If the terminal sends additional data, the H24 transmits another frame
• If the terminal sends only (a null frame), the H24 turns off the transmit
carrier and sends the CONNECT result code to the terminal
• If five seconds elapses from the time the H24 reports the OK result code without any
additional data transmitted from the terminal, the H24 turns off the transmit carrier, returns to
command mode, and sends the ERROR result code to the terminal.
Command Type Syntax Response/Action Remarks
Set
FTH =
(Send data stream
)
CONNECT
OK
or:
NO CARRIER
The Set command causes the H24 to
transmit data framed in HDLC
protocol using the modulation mode
selected.
Note: MOD = 3 (Clause 2/V.21) rate 300 bps, is mandatory.
If the H24 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.
Table 3-35: Command Modulation Select Codes - Modulation Parameters
Value Modulation TrainTime 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
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 H24 detected the terminating sequence
(Terminal sends DCS frame data, as described in ITU-T30 with terminating sequence and drops the
carrier)
OK
April 15, 2010 H24 - AT Commands Reference Manual 3-63