Canon fax basic 2000 サービスマニュアル

Canon

CHAPTER

6

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2

3

4

5

6

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6

FACSIMILE SYSTEM

1. INTRODUCTION...................................................................... 6-2

2. SCNT BOARD.......................................................................... 6-3

System Control Section................................................... 6-3

Communications Control Section .................................... 6-4

Reading Control Section ................................................. 6-4

Printer Control Section .................................................... 6-4

3. NCU BOARD............................................................................ 6-5

Off-hook Detection .......................................................... 6-6

Formation of DC Loop ..................................................... 6-6

Detection of Calling Identification (CI) ............................. 6-9

Line Signal Monitor ....................................................... 6-10

Dial Control ................................................................... 6-11

2-wire/4-wire Conversion............................................... 6-12

Protective Circuits ......................................................... 6-12

Telephone Connection Control ...................................... 6-14

Relay Operations........................................................... 6-17

4. OPCNT BOARD ..................................................................... 6-18

Detection of Button Input............................................... 6-18

LED Lighting Control ..................................................... 6-21

Display Indication Control.............................................. 6-21

5. FLOW OF IMAGE SIGNALS .................................................. 6-22

Transmission ................................................................. 6-22

Reception ...................................................................... 6-23

6. POWER SUPPLY UNIT.......................................................... 6-24

Switching Regulator ...................................................... 6-24

Configuration of Power Supply Unit on a Facsimile....... 6-31

7. G4CNT BOARD ..................................................................... 6-32