Canon Super G3 FAX Board-T1, Portable Manual

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Chapter 2
4
2.1.3 NCU PCB
0010-9362
F-2-3
2-Line/4-Line Conversion Circuitry
Signals from a 2-line telephone line are converted into transmission signals and reception signals (4 lines). It also serves to prevent intrusion of signals from the
modem into the reception circuit.
Dial Pulse Generator Circuit
It turns on and off the relay within the circuit using the control signal from the Modem PCB to generate dial pulses so that dial signals will be generated by the fax
on a dial-pulse line.
Off-Hook Detection Circuit
Detects an off-hook state by monitoring the dirt current flowing in the circuit when the telephone connected to the extension telephone terminal is put off the hook.
Line Voltage Conversion Circuit
The primary side of the NCU PCB is controlled by a line voltage of +48 VDC. The DC component is cut out by the work of a capacitor and, as a result, only audio
signals are converted into voltages suited to the level of the modem.
2.2 Product Specifications
2.2.1 Product Specifications
0010-8788
T-2-1
Item Description
Communication G3
Applicable lines PSTN (Public Switched Telephone Network)
Modulation method <G3 image signal>
ITU-T V.27ter (2.4Kbps, 4.8Kbps)
ITU-T V.29 (7.2Kbps, 9.6Kbps)
ITU-T V.17 (TC 7.2Kbps, TC 9.6Kbps, 12Kbps, 14.4Kbps)
ITU-T V.34 (2.4Kbps, 4.8Kbps, 7.2Kbps, 9.6Kbps, 12Kbps, 14.4Kbps,
16.8Kbps, 19.2Kbps, 21.6Kbps, 24Kbps, 26.4Kbps, 28.8Kbps, 31.2Kbps,
33.6Kbps)
<G3 procedure signal>
ITU-T V.21 No.2 (300bps)
ITU-T V.8, V.34 (300bps)
Transmission speed 33.6Kbps, 31.2Kbps, 28.8Kbps, 23.4Kbps, 24Kbps, 21.6Kbps, 19.2Kbps,
16.8Kbps, 14.4Kbps, 12Kbps, TC 9.6Kbps, TC7.2Kbps, 9.6Kbps,
7.2Kbps, 4.8Kbps, 2.4Kbps
auto fallback function
Coding method JBIG, MMR, MR, MH
G3-specific abridged procedure no
Dial Tone Detection yes
Modem IC CONEXANT FM336 Plus
Error correction ITU-T ECM
Transmission original size A3, A4, A4R, A5, A5R, B4, B5, B5R, LTR, LTRR, LGL, 11x17, STMT,
STMTR
ADF: double-sided originals accepted
Scanning line density Standard (200 x 100 dpi): 8 dots/mm x 3.85 lines/mm
Fine (200 x 200 dpi):8 dots/mm x 7.7 lines/mm
Super Fine (300 x 300 dpi): 8 dots/mm x 15.4 lines/mm
Ultra Fine (400 x 400 dpi): 16 dots/mm x 15.4 lines/mm
Halftone 256 gradations
Recording unit maximum reception size: A3 (297mm x 420mm)
MODEM IC
FM336Plus
(IC1)
2-Line/4-Line
Conversion
Circuitry
Vref
generation
Formation
of DC Loop
Polarity
inversion
S relay
H relay
P relay
CML relay
Line signal
monitor
L1
T1
T2
CT2
CT1
L2
Hook
detection
Hook
detection
Detection
of CI
PATCH
(IC40)
Image Processor PCB
NCU PCB
Modem PCB
MPU
(IC1)