7.7.2. MODEM CIRCUIT OPERATION
The modem (IC505) has all the hardware satisfying the ITU-T standards mentioned previously.
When the ASIC IC501 (61) is brought to a low level, the modem (IC505) is chip-selected and the resistors inside IC are selected
by the select signals from ASIC (IC501) ADR0-ADR4 (pin 81~85). Commands are written through the data bus, and all processing
is controlled by the ASIC (IC501) according to ITU-T procedures. Here, the INT signal dispatched from IRQ (pins 108 and 121 of
IC505) to the ASIC (IC501) implements post processing.
This modem (IC505) has an automatic application equalizer. With training signal 1 or 2 at the time of G3 reception, it can
automatically establish the optimum equalizer. The modem (IC505) clock is supplied by X503.
1. Facsimile Transmission/DTMF Line Send
The digital image data on the data bus is modulated in the modem (IC505), and sent from pin 69, Analog SW IC509(1
→
2),
amplifier IC511(2
→
1) and the NCU section to the telephone line.
Refer to CHECK SHEET (P.105).
2. Facsimile Reception
The analog image data which is received from the telephone line passes through the NCU section and enters pin 60 of the
modem (IC505). The signals that enter pin 60 of the modem (IC505) are demodulated in the board to digital image signals, then
placed on the data bus.
In this case, the image signals from the telephone line are transmitted serially. Hence, they are placed on the bus in 8 bit units.
Here, the internal equalizer circuit reduces the image signals to a long-distance receiving level.
This is designed to correct the characteristics of the frequency band centered around 3 kHz and maintain a constant receiving
sensitivity.
It can be set in the service mode.
Refer to CHECK SHEET (P.105).
3. DTMF Transmission (Monitor tone)
The DTMF signal generated in the modem (IC505) is output from pin 69, and the NCU section to the telephone line the same
as facsimile transmission signals.
(DTMF Monitor Tone)
Refer to CHECK SHEET (P.105).
4. Busy/Dial Tone Detection
The path is the same as FAX receiving. When it is detected, the carrier detect bit of the resistor in the modem (IC505) becomes
1, and this status is monitored by ASIC (IC501).
144
KX-FP342BX
Summary of Contents for KX-FP342BX
Page 21: ...4 1 2 COMPONENT LOCATIONS 21 KX FP342BX ...
Page 33: ...5 2 2 HOW TO REMOVE THE OPERATION PANEL BLOCK 33 KX FP342BX ...
Page 34: ...5 2 3 HOW TO REMOVE THE OPERATION BOARD AND LCD 34 KX FP342BX ...
Page 35: ...5 2 4 HOW TO REMOVE THE IMAGE SENSOR CIS 35 KX FP342BX ...
Page 36: ...5 2 5 HOW TO REMOVE THE THERMAL HEAD 36 KX FP342BX ...
Page 37: ...5 2 6 HOW TO REMOVE THE PLATEN ROLLER AND BACK COVER 37 KX FP342BX ...
Page 38: ...5 2 7 HOW TO REMOVE THE PICKUP ROLLER 38 KX FP342BX ...
Page 39: ...5 2 8 HOW TO REMOVE THE CASSETTE LEVER 39 KX FP342BX ...
Page 40: ...5 2 9 HOW TO REMOVE THE BOTTOM FRAME 40 KX FP342BX ...
Page 41: ...5 2 10 HOW TO REMOVE THE DIGITAL ANALOG POWER SUPPLY SENSOR BOARDS AND AC INLET 41 KX FP342BX ...
Page 42: ...5 2 11 HOW TO REMOVE THE MOTOR BLOCK AND SEPARATION ROLLER 42 KX FP342BX ...
Page 43: ...5 2 12 HOW TO REMOVE THE GEARS OF MOTOR BLOCK 43 KX FP342BX ...
Page 44: ...5 3 INSTALLATION POSITION OF THE LEAD WIRES 44 KX FP342BX ...
Page 57: ...6 5 2 SREVICE MODE SETTINGS Note The above values are the default values 57 KX FP342BX ...
Page 71: ...71 KX FP342BX ...
Page 85: ...85 KX FP342BX ...
Page 86: ...CROSS REFERENCE TEST FUNCTIONS P 50 86 KX FP342BX ...
Page 87: ...CROSS REFERENCE TEST FUNCTIONS P 50 87 KX FP342BX ...
Page 88: ...CROSS REFERENCE TEST FUNCTIONS P 50 88 KX FP342BX ...
Page 89: ...CROSS REFERENCE TEST FUNCTIONS P 50 89 KX FP342BX ...
Page 90: ...90 KX FP342BX ...
Page 91: ...91 KX FP342BX ...
Page 92: ...CROSS REFERENCE TEST FUNCTIONS P 50 92 KX FP342BX ...
Page 96: ...96 KX FP342BX ...
Page 100: ...I O and Pin No Diagram 100 KX FP342BX ...
Page 104: ...6 6 7 3 NG EXAMPLE 104 KX FP342BX ...
Page 109: ...6 6 9 2 TROUBLESHOOTING FLOW CHART 109 KX FP342BX ...
Page 115: ...6 6 13 THERMAL HEAD SECTION Refer to THERMAL HEAD P 129 115 KX FP342BX ...
Page 116: ...7 CIRCUIT OPERATIONS 7 1 CONNECTION DIAGRAM 116 KX FP342BX ...
Page 118: ...7 2 1 GENERAL BLOCK DIAGRAM 118 KX FP342BX ...
Page 120: ...7 3 2 MEMORY MAP 120 KX FP342BX ...
Page 128: ...7 4 2 BLOCK DIAGRAM 128 KX FP342BX ...
Page 131: ...TIMING CHART i Print Duty 50 or less ii Print Duty more than 50 131 KX FP342BX ...
Page 150: ...150 KX FP342BX ...
Page 159: ...8 REFERENCE MATERIAL DATA 8 1 TERMINAL GUIDE OF THE ICs TRANSISTORS AND DIODES 159 KX FP342BX ...
Page 162: ...8 3 TEST CHART 8 3 1 ITU T No 1 TEST CHART 162 KX FP342BX ...
Page 163: ...8 3 2 ITU T No 2 TEST CHART 163 KX FP342BX ...
Page 164: ...9 FIXTURES AND TOOLS 164 KX FP342BX ...
Page 165: ...10 CABINET MECHANICAL AND ELECTRICAL PARTS LOCATION 10 1 GENERAL SECTION 165 KX FP342BX ...
Page 166: ...10 2 OPERATION PANEL SECTION 166 KX FP342BX ...
Page 167: ...10 3 BACK COVER SECTION 167 KX FP342BX ...
Page 168: ...168 KX FP342BX ...
Page 169: ...10 4 UPPER CABINET SECTION 169 KX FP342BX ...
Page 170: ...10 5 LOWER CABINET P C BOARD SECTION CROSS REFERENCE MOTOR SECTION P 171 170 KX FP342BX ...
Page 171: ...10 6 MOTOR SECTION 10 7 ACTUAL SIZE OF SCREWS 171 KX FP342BX ...
Page 172: ...11 ACCESSORIES AND PACKING MATERIALS 172 KX FP342BX ...
Page 180: ...8 REFERENCE MATERIAL DATA 8 1 TERMINAL GUIDE OF THE ICs TRANSISTORS AND DIODES 159 KX FP342BX ...
Page 183: ...8 3 TEST CHART 8 3 1 ITU T No 1 TEST CHART 162 KX FP342BX ...
Page 184: ...8 3 2 ITU T No 2 TEST CHART 163 KX FP342BX ...
Page 185: ...9 FIXTURES AND TOOLS 164 KX FP342BX ...
Page 186: ...10 CABINET MECHANICAL AND ELECTRICAL PARTS LOCATION 10 1 GENERAL SECTION 165 KX FP342BX ...
Page 187: ...10 2 OPERATION PANEL SECTION 166 KX FP342BX ...
Page 188: ...10 3 BACK COVER SECTION 167 KX FP342BX ...
Page 189: ...168 KX FP342BX ...
Page 190: ...10 4 UPPER CABINET SECTION 169 KX FP342BX ...
Page 191: ...10 5 LOWER CABINET P C BOARD SECTION CROSS REFERENCE MOTOR SECTION P 171 170 KX FP342BX ...
Page 192: ...10 6 MOTOR SECTION 10 7 ACTUAL SIZE OF SCREWS 171 KX FP342BX ...
Page 193: ...11 ACCESSORIES AND PACKING MATERIALS 172 KX FP342BX ...