G3 FACSIMILE COMMUNICATIONS
5–78
• Probing (Phase 2)
The line characteristics are measured and modulation-related parameters,
such as symbol rate, are set.
Transmitter
Signal
Abbre-
viation
Meaning
Remarks
INFO
sequence
INFO0c
Indicate modem capa-
bilities, such as baud
rate and frequency
transmission function
(two frequency bands
used to measure line
characteristics), and
request adjustment.
Transmission
speed: 600bps
Tone B
B
Modem synchroniza-
tion with a 1200-Hz
tone signal.
The phase of the
B- signal is
inverted 180
degrees from the
phase of the B
signal.
Tone B
B
Probing signal
L1
L1
Tone signal for analyz-
ing line characteristics
by probing.
Probing:
Measurement of
line characteris-
tics.
Tone signal in the
range 150 to
3750 Hz in 150-
Hz steps.
Probing signal
L2
L2