Olivetti d-Color MF4003 Service Manual page 676

d-Color MF4003/MF3303
Main channel data
Transmitting modem
Receiving modem
Main channel re-synchronization procedure and Turn-off
• The receiving modem re-synchronizes the main channel by using the PP signal. After B1, starts receiving Primary Data.
• The transmitting modem sends the scrambled 1's for 35 ms after Primary Data transmission has been completed.
• Both modems move to the control channel re-synchronization procedure or the control channel startup procedure.
S Signal which sends alternately 0 point and a point which rotated 0 point counterclockwise by 90 degrees
Signal which sends alternately a point which rotated 0 point counterclockwise by 180 degrees and a point which rotated 0
point counterclockwise by 270 degrees
PP Special for adjusting an equalizer
B1 High-speed signal of one frame length which is sent at the end of a series of startup sequence in the selected modulation
parameter.
Control channel data
Transmitting modem
Receiving modem
Control channel data
(8) Other
(a) Minimum reception signal level (RLSD) (half-duplex mode only)
• The reception circuit is turned to ON when the signal becomes 43 dBm or more.
• When the signal becomes 48 dBm or less, the reception circuit is turned OFF within 20 to 25 ms after it has exceeded the thresh old.
(b) Data frame structure
• All data transmitted in V.34 (after the Phase 4) is treated in the following frame format.
• J: The number of data frames within one super frame
• P: The number of mapping frames within one data frame
Super frame
Data frame
Mapping frame
Four-dimensional symbol
Modulation Speed
2400 baud
2743 baud
2800 baud
3000 baud
3200 baud
3429 baud
8.2 FUNCTION
8.2.1 Telephone function
(1) TEL/FAX switching
(a) Outline
• A function to switch telephone and FAX automatically after reception. (Depends on Country spec.)
(b) Operation
1. When CNG is not detected for 2 seconds (or 4 seconds, following address parameter) after line seizure, this function sends voice
response message 1 and continues CNG detection.
2. If voice response 1 is sent and CNG detection is continued for 4 seconds but could not be detected, external ringer is sent to the
externally installed phone.
Service Manual
24T
8T 16T and more
Sh ALT
Sh
120T or less
±
70 5 ms
Sh ALT
Sh
Between 16T and 120T
24T 8T
128T
16T
S PP B1
S Main channel
70 ± 5 ms
To Control channel re-synchronization / Control channel startup procedure
280 ms
0 1 ...
40 or 35 ms
0 1 ...
J=0 1 2 3
1
K=0
E control channel data
control channel data
E
Turn-off
35 ms
Data Scrambled 1's
70 ± 5 ms
J-1
P-1
J
7
8
7
7
7
8
P-102
P THEORY OF OPERATION > 8. FK-517
P
12
12
14
15
16
15
Y119930-3