January 2001 © TOSHIBA TEC
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GD-1060 DIALING AND COMMUNICATION PROCEDURE
b-2)
Probing/Ranging (Phase 2)
Line characteristics are measured, then the parameter setting for modulation such as the
modulating speed, is made.
• Transmitter
• Receiver
Signal name
INFO sequence
Tone A
Tone A
INFO sequence
Abbreviation
INFO0a
A
A
INFO0h
Meaning
It indicates the modem capability
such as the modulating speed and
frequency transmission capability.
Synchronization between modems
by 2400-Hz tone
Based on the analysis of the line
probing signal sent from the trans-
mitter, it indicates the pre-empha-
sis filter and modulating speed to
be used for the data transmission.
Remark
Transmission rate: 600 bps
A is a signal that shifts
phase A 180°.
Transmission rate: 600 bps
Signal name
INFO sequence
Tone B
Tone B
Line probing
signal L1
Line probing
signal L2
Abbreviation
INFO0c
B
B
L1
L2
Meaning
It indicates modem capability such
as modulating speed and fre-
quency transmission capability
(two frequency bands - high and
low - used for measuring the line
characteristics), and requests for
adjusting.
Synchronization between modems
by 1200-Hz tone
Tone for analyzing the line char-
acteristics by probing
Remark
Transmission rate: 600 bps
B is a signal that shifts
phase B 180°.
Probing is to measure the
line characteristics.
Tone between 150 Hz and
3750 Hz in units of 150 Hz