User`s manual

AT Command Reference Manual
1048 5-1
5. FAX CLASS 1 COMMANDS
5.1 FAX I/O PROCESSING
The fax I/O interface supports asynchronous serial and parallel interfaces. The interface rate is 19200 bps. The character
format is 8 bits data, no parity, and 1 stop bit. Start and stop elements are removed from the transmit data and added to the
receive data. Both transmit and receive data are buffered. Flow control using XON/XOFF (DC1/DC3) or RTS/CTS is
provided.
Unique control character strings are identified, filtered, or reinserted into the I/O data stream. These control characters and
their resultant action are described below.
5.1.1 DTE-to-Modem Transmit Data Stream
Characters Detected Action Taken
<DLE><data> Delete <DLE><data> characters.
<DLE><ETX> Recognize as a string terminator and take appropriate action.
<DLE><DLE> Replace with single <DLE> character.
5.1.2 Modem-to-DTE Receive Data Stream
Characters Detected Action Taken
<DLE> Insert extra <DLE> ahead of <DLE>.
The modem also identifies the end of a frame by inserting <DLE><ETX> into the data stream after the FCS bytes.
5.1.3 Fax Mode Selection
Fax class 1 commands are identified in Table 5-1. Fax modes and rates are determined by the AT+F commands as
described in Section 5.2.
Table 5-1. Fax Class 1 Commands
Command Function
Service Class ID
+FCLASS= Service Class
Fax Class 1 Commands
+FAE=n Data/Fax Auto Answer
+FTS=n Stop Transmission and Wait
+FRS=n Receive Silence
+FTM=n Transmit Data
+FRM=n Receive Data
+FTH=n Transmit Data with HDLC Framing
+FRH=n Receive Data with HDLC Framing
5.1.4 Fax Origination
Origination of fax calls is made using the ATD command. Upon completion of the dial function, a calling tone at 1100 Hz is
transmitted, with a cadence of 0.5 seconds on and 3 seconds off. The modem automatically enters mode +FRH=3 and
sends the CONNECT message to the DTE when FSK flags are detected from the remote.