6
6.0 Operation
Modem operation supports data modem processing, fax modem processing and
common call progress processing.
The AT+FCLASS command allows the operator to select either data or fax
operation.
AT+FCLASS=0 Data mode
AT+FCLASS=1 Fax mode Class 1
6.1 Data Modes
6.1.1 Data Mode Selection
Data mode operation is defined by the AT commands and S register settings
described in Chapter 4 and Chapter 5. Data rate selection is determined by the
speed of the originating and answering modems as listed in Table 6-1.
Table 6-1. Data Rate Selection
Originate Mode
Answer Mode
300
1200
2400
300
1200
2400
300
300
300
1200
1200
1200
1200
1200
2400
6.1.2 Data Modem Processing
Data modem processing is explicitly defined in CCITT V.22 bis, CCITT V.22,
Bell 212A, and Bell 103 documentation. All modulation, waveform spectrum,
and data processing functions conform to the appropriate specifications with the
following exceptions:
1. CTS is ON all the time and does not go OFF during handshake.
2. DSR is always ON in parallel mode operation.
3. The rate change request option is not supported for V.22 bis.
4. V.22 operation supports only Alternative B, mode ii (1200 bps
asynchronous, 10 bit characters)
D224ATLVDSC
Conexant
6-1
CONEXANT [ CONEXANT SYSTEMS, INC ]
