Toshiba GD-1151 Manuale Utente

GD-1150/1151/1200/1201/1160/1260

© 2003 - 2008 TOSHIBA TEC CORPORATION All rights reserved

DIALING/COMMUNICATION CONTROL

3 - 16

- Probing/Ranging (Phase 2)

Examines the line characteristics and sets the parameters for the modulation related items such 
as the modulating speed.

Transmitter

Receiver

INFO sequence

INFO0c

Informs the modem capability 

such as modulating speed 

and frequency transmission 

capability (two frequency 

bands (high and low) used to 

examine the line characteris-

tics), and requests for adjust-

ing.

Transmission rate: 600 bps

Tone B

B

Synchronization between the 

modems by 1200 Hz tone sig-

nal

 is a signal that shifts the 

phase B 180°.

Tone 

Line probing signal L1

L1

Tone signal to analyze the line 

characteristics by probing

Probing is to examine the line 

characteristics.

Tone signal between 150

Hz and 3,750 Hz in units of 

150 Hz

Line probing signal L2

L2

INFO sequence

INFO0a

Informs the modem capability 

such as the modulating speed 

and frequency transmission 

capability.

Transmission rate: 600 bps

Tone A

A

Synchronization between the 

modems by 2,400 Hz tone 

signal

 is a signal that shifts the 

phase A 180°.

Tone 

INFO sequence

INFO0h

Based on the analysis of the 

line probing signal sent from 

the transmitter, it informs the 

pre-emphasis filter and modu-

lating speed to be used for the 

data transmission.

Transmission rate: 600 bps

B

B

B

A

A

A