r6781-12 Conexant Systems, Inc., r6781-12 Datasheet - Page 75

Manufacturer Part Number

r6781-12

Description

Embedded Modem Family

Manufacturer

Conexant Systems, Inc.

Datasheet

1.R6781-12.pdf (104 pages)

EmbeddedModem Family

Table 6-3. Terminal Called by a Fax Machine

D224ATLVDSC

AT&C1

ATS9=n

AT+FAA=1

ATA

DTE Command

—

RING

FAX

CONNECT

DCE Response

—

Assume DCE in fax mode (FCLASS = 1), DTE is running fax

communication package, and DCD is off.

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.

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.

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.

DCE ends CONNECT response at the fax rate (i.e., 19,200 bps).

Conexant

Comments

6.4 Data/Fax Auto Answering

6-11