Fax Operation
V.3400
9-9
CONNECT result code. HDLC flags will continue to be sent until the
first byte of data is received from the DTE or until 5 seconds elapses
with no data. For additional information, refer the Class 1 specification.
HDLC Receive +FRH=
(Mod)
The command +FRH= (Mod) causes the modem to receive HDLC
framed data using the modulation and speed selected with the (Mod)
parameter. If the selected carrier is detected, a CONNECT result code is
sent to the DTE; if a different signal is detected, the modem sends a
+FCERROR (CONNECT ERROR) result code and returns to command
mode. This command will be aborted if the DTE sends any character to
the modem other than DC1 or DC3 during this mode. For additional
information, consult the Class 1 specification.
Test Supported Range of Values +FT
x=?, +FRx=?
The supported range of values for any of the fax transmit or receive
commands can be determined with the +FTx=? or +FRx=? command
where x is M, H, or S. The normal transmit and receive capabilities are
interrogated with +FTM=? and +FRM=?, while the HDLC transmit
and receive capabilities are interrogated with +FTH=? and +FRH=?.
Since the modem can send and receive normal data or HDLC data at all
valid speeds up to 14400 bps, the modem returns the information text 3,
24, 48, 72, 73, 74, 96, 97, 98, 121, 122, 145, 146 for any of these four
commands if x is M or H. For the commands +FTS=? or +FRS=? the
modem returns the information text 0-255, indicating an allowed time
interval from 0 to 2.55 seconds. The appropriate information text is
always preceded and followed by <CR><LF> and followed by an
appropriate result code response.
Class 1 Result Code +FCERROR
If the modem detects any carrier or tone that differs from that specified
in a +FRM or +FRH command, it sends the +FCERROR result code
and returns to command state, allowing the DTE to attempt a recovery.
The numeric form of this response is +F4.
