RC224ATL/224ATLV
6.0 Operation
EmbeddedModem Family
6.4 Data/Fax Auto Answering
Table 6-3. Terminal Called by a Fax Machine
DTE Command
DCE Response
Comments
—
—
Assume DCE in fax mode (FCLASS = 1), DTE is running fax
communication package, and DCD is off.
AT&C1
ATS9=n
AT+FAA=1
—
OK
OK
OK
DTE commands DCD to follow data carrier.
DTE defines the data mode connection time.
DTE enables data/fax auto answer mode.
—
DTE sets the communication rate to the data modem rate (e.g., 2400
bps) prior to an incoming call.
—
ATA
RING
Terminal is being called.
—
—
DTE commands DCE to go off-hook and start auto answer.
—
DCE starts data modem handshaking. If receive data signal is not
detected within S9 seconds from going off-hook, DCE switches to fax
mode and automatically sets FCLASS=1.
—
—
—
FAX
DCE switches to fax mode handshaking and sends “FAX” message at
the data modem rate (e.g., 2400 bps).
—
DCE sends 3 seconds of 2100 Hz answer tone, enters V.21 transmit
mode, and sends HDLC flags.
CONNECT
DCE ends CONNECT response at the fax rate (i.e., 19,200 bps).
D224ATLVDSC
Conexant
6-11
CONEXANT [ CONEXANT SYSTEMS, INC ]
