Comtrol AT Commands - Manual (Page 62)

AT Commands for CX81801/CX06833/CX81300/CX06827 Modems Reference Manual
Conexant 102184B
3-36
In band processing of AT commands
When in-band control sequences are enabled, the modem responds to EM shielded AT
commands via the extend-0 CONTROL sequence. This command may be used to
transmit any AT commands to the modem as follows:
EM <extend-0> <length> <CONTROL> <AT Command without AT and trailing
carriage return>
Upon receipt of an in-band command, the modem responds with the extend-0 STATUS
REPORT sequence. This sequence will contain the response to the AT command issued
via the CONTROL sequence with the trailing <cr> <lf> omitted:
EM <extend-0> <length> <STATUS> <AT Command response without trailing LF>
Example: Send +VRID=2 command to the modem and respond with terse caller ID:
EM <60h> <27h> <42h> +VRID=2
Note: <length> is 27h corresponding to 27h-1Fh=8. This is the length of the sequence
following the <length> octet.
The modem responds to this command by transmitting the caller ID information to the
DTE via the in-band sequence:
EM <60h> <length> <62h> <raw caller ID information>
EM<60h><22h><62h>OK
In this case, the <length> octet is the actual length of the raw caller ID + 1 + 1Fh.
In band signaling of CTS and Ring Indicate (Circuit 106 and Circuit 125)
Whenever the V.24 circuit selected via the +IBC command changes, the modem will
send an unsolicited EM shielded frame to the DTE to inform the DTE of the new state.
This is used for CTS and RI. For MOH applications, the DTE is specifically interested in
circuit 125 (Ring Indicate).
When RI is asserted, the sequence EM <125on> or 19h 6Bh is sent to the DTE.
When RI is de-asserted, the sequence EM <125off> or 19h 6Ah is sent to the DTE.