Motorola V.3400 Manuel d'utilisation - Page 4

Parcourez en ligne ou téléchargez le pdf Manuel d'utilisation pour {nom_de_la_catégorie} Motorola V.3400. Motorola V.3400 10 pages.

Fax Operation

The Class 1 standard assumes a serial asynchronous DTE-DCE connec-

tion using EIA-232D (or CCITT V.24) circuits. EIA-232D circuits AB

(signal ground), BA (transmitted data), and BB (received data) are

required for fax operation, while additional circuits are optional. Refer

to Chapter 2 for hardware installation and EIA-232D data interface

information.

The modem uses inband unidirectional DC1/DC3 (XON/XOFF) flow

control to match the DTE-DCE data rate to the line signaling rate (hard-

ware RTS/CTS is optional). Since 1200 bps is the minimum rate needed

to support T.30 Phase C data transfer using V.29 9600 bps, a serial port

data rate of at least 19200 bps should be used with the modem. Since

flow control is used, this rate should not be changed during fax opera-

tion. The modem detects the DTE-DCE data rate from the AT command

prefix as described in Chapter 5.

CLASS 1 COMMANDS

The commands in this section are normally issued by the fax software

and not by the user. They are provided here for reference. While only

the lower order 7 bits of each character are used for commands and

parameters, Phase C data transmission or reception requires all 8 data

bits. Therefore, a data format which uses 8 data bits should be used for

fax mode.

Dial Command D

The dial command D, described in Chapter 5, tells the modem to go off

hook, dial, and begin call origination. For fax operation, set the modem

for Service Class 1 operation before the dial command is issued; use the

+FCLASS=1 command.

The dial modifier, except R, can also be used in fax mode. Depending

on the X option selected, the modem will return the BUSY and NO

DIALTONE result codes as appropriate. If the modem is in the online

command state when a dial command is issued (e.g., a connection has

already been established), the modem returns an ERROR result code.

The NO CARRIER result code indicates that a connection could not be

established (no carrier detected) within the number of seconds specified

in status register S7, or the dial command has been aborted due to a

character sent from the DTE.

9-4

V.3400