6.0 Operation
RC224ATL/224ATLV
6.4 Data/Fax Auto Answering
EmbeddedModem Family
Table 6-2. Terminal Called by a 1200 bps Data Modem
DTE Command
DCE Response
Comments
—
—
Assume DCE in fax mode (FCLASS = 1), DTE 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 determines caller as data modem and establishes connection
with caller.
—
—
—
DCE turns on DCD to indicate data connection is established.
DCE then waits in on-line command mode.
—
—
DATA
OK
DCE indicates data modem connection is established.
AT commands
DTE optionally sends any commands to DCE to restore conditions
required by data modem communications package.
ATO
—
CONNECT 1200
DTE instructs DCE to switch from on-line command to data state.
DTE then transfers control to data modem package.
—
—
—
Fax package remains in background polling DCD to check connection
status.
—
—
DCE response will then be read by data modem communication rate
to 1200 bps.
—
—
—
—
“Callers data”
DTE sends/receives data.
—
NO CARRIER
—
Caller hangs up. DTE detects carrier loss and turns off DCD.
DCE indicates connection with caller has terminated.
DTE fax communications software, running in background, sees DCD
turn off, and regains control from data modem package.
6-10
Conexant
D224ATLVDSC
CONEXANT [ CONEXANT SYSTEMS, INC ]
