Fax Operation
9-6
V.3400
Off Hook H1
The H1 command instructs the modem to go off hook. In fax mode, this
might be used when the user has used manual dialing to place a fax call.
In this case, no CNG tones are generated and the initial +FRH=3 is not
implied; it must be explicitly issued by the software.
Class 0 Operation +FCLASS=0
Setting the Service Class to 0 with the +FCLASS=0 command sets the
modem in data mode. This default setting is normally only changed by
software if needed.
Class 1 Operation +FCLASS=1
Setting the Service Class to 1 with the +FCLASS=1 command config-
ures the modem as a Class 1 fax modem. This command is normally
only issued by the fax software if needed. When set, the LCD displays
FAX CLASS 1 MODE.
Service Class Indication +FCLASS?
The current Service Class setting can be determined with the
+FCLASS? command. A 0 response indicates the modem is configured
for data mode while a 1 indicates it is set for fax mode. This informa-
tion text is preceded and followed by <CR><LF> in addition to being
followed by an appropriate result code response.
Service Class Capabilities +FCLASS=?
The available Service Classes can be revealed by the +FCLASS=?
command. The modem responds with the information text 0, 1
(preceded and followed by <CR> <LF>), indicating that the modem
supports both data communication and Class 1 fax operation.
Transmit Silence +FTS=
(Time)
The command +FTS=(Time) causes the modem to wait in silence for
the specified amount of time and then send the OK result code to the
DTE. The (Time) value is in 10 ms increments from 0 to 2.55 seconds.
The modem aborts the command and sends an OK result code if the
DTE sends an additional character, which is discarded, during the
command execution. This command returns an ERROR result code if
issued while the modem is on hook.
