ZyXEL Communications COMET 336 User Manual page 58

Data
The modem dials and reports call progress to the DTE as in all modes. A data
handshake is pursued according to the current configuration.
Adaptive Originate (Dial with Voice/Data/Fax Discrimination)
The DTE may wish to originate a call which adapts to the remote answerer. For
instance, the user may wish to send a voice message if a human picks up the telephone,
but a facsimile if a fax machine answers. The modem can facilitate this type of adaptive
originate by extending what it does for the directed originate modes. After determining
that the remote station has picked up the line, the modem goes back to Online Voice
Command Mode, thus terminating the connecting state. Once in this mode, the modem
reports what it receives from the answerer via specific result codes to the DTE. The
DTE can then have the option of pursuing a data, fax, or voice/audio connection.
7.2.2 Call Establishment - Answer Directed Answer (Answer as a specific modem
type)
If the DTE wants to be only one kind of answerer (i.e., voice/audio, fax, or data), it can
configure the modem to answer exclusively in the chosen mode.
Voice/Audio
The modem is configured to answer in Voice/Audio Mode only and assumes the caller
will cooperate. After going off-hook, the voice VCON is issued, no answer tone is
generated, and the modem is immediately placed in Online Voice Command Mode. The
DTE typically responds by sending a greeting message of some type, and DTMF tone
recognition/reporting can be enabled. Eventually, an incoming voice message can be
recorded by the host. (Unpredictable results occur if the caller is not prepared for a
voice call.)
Fax
The modem is configured to answer in Fax Class 1 or Fax Class 2 Mode only, and it
assumes the caller is going to cooperate. This configuration has the effect of disabling
Voice/Audio Mode, forcing +FCLASS to either 1 or 2, and forcing both +FAA and
+FAE to 0.
Data
The modem is configured to answer in Data Mode only and assumes the caller is going
to cooperate. This configuration has the effect of disabling Voice/Audio Mode, forcing
+FCLASS = 0, and forcing both +FAA and +FAE to 0.
Adaptive Answer (Answer with Voice/Data/Fax Discrimination)
In normal operation, it is desirable for a modem supporting fax and voice to provide the
ability to discriminate between the two when answering unsolicited or unattended calls.
(It is most often the case that a fax is received or a voice message recorded when
nobody is present.)
Voice Operation 51