Toshiba GD-1220, GD-1221 service manual Standard procedure Transmitter Receiver, Line closed

2) Standard procedure

	Transmitter	Receiver
		Line closed
Network interaction
(Phase 1)
(	P3-14)
Probing/Ranging
(Phase 2)
(	P3-15)
Equalizer/Echo
canceller training
(Phase 3)
(	P3-16)
Final training
(Phase 4)
(	P3-16)
Control channel
(	P3-17)
Primary channel
(	P3-18)
Image data
(	P3-18)
Communication
end procedure
(	P3-19)
	Line opened	Line opened

The available modulation mode is in formed. Each declares that it has V.34 capability. The procedure moves to V.34 in the phase 2.

After the information about the modem capa- bility is exchanged, the receiver determines the modulation speed based on the result of reception of the probing signal which was sent by the transmitter.

To determine the image transmission speed, the transmitter sends a training signal.

The optimum image transmission speed is determined according to the training signal received.

The pre-FAX transmission which is the same as that for the normal T.30 is performed at 1,200 bps.

The training signal is sent with the determined parameter, then the image data are sent.

The post-FAX transmission which is the same as that for the normal T.30 is performed at 1,200 bps.

3

© 2006 - 2008 TOSHIBA TEC CORPORATION All rights reserved	GD-1220/1221
	DIALING/COMMUNICATION CONTROL

3 - 13