6.6.2. MODEM CIRCUIT OPERATION
The modem (IC5) has all the hardware satisfying the ITU-T standards mentioned previously.
When the ASIC IC1 (61) is brought to a low level, the modem (IC5) is chip-selected and the resistors inside IC are selected by the
select signals from ASIC (IC1) ADR0-ADR4. The commands are written through the data bus, and all the processing is controlled
by the ASIC (IC1) according to ITU-T procedures. The INT signal dispatched from IRQ1, 2 (pins 108 and 121 of IC5) to ASIC (IC1)
when the transmission data is accepted and the received data is demodulated, the ASIC (IC1) implements post processing. This
modem (IC5) has an automatic application equalizer.
With training signal 1 or 2 during G3 reception, it can automatically establish the optimum equalizer. The modem (IC5) operates
using the 32.256 MHz clock (X3).
1. Facsimile Transmission
The digital image data on the data bus is modulated in the modem (IC5), and sent from pin 69 via analog SW (IC9) and
amplifier IC10 and the NCU section to the telephone line.
Refer to 2.3.4.4.1. Check Sheet
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 (IC5). The signals that enter pin 60 of the modem (IC5) 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 about 3 kHz and maintain a constant receiving
sensitivity. It can be set in the service mode.
Refer to 2.3.4.4.1. Check Sheet
3. DTMF Transmission (Monitor tone)
The DTMF signal generated in the modem (IC5) is output from pin 69, and is then sent to the circuit on the same route as used
for facsimile transmission.
Refer to 2.3.4.4.1. Check Sheet
(DTMF Monitor Tone)
Refer to 2.3.4.4.1. Check Sheet
4. Call Tone Transmission
This is the call signal which is generated in the ASIC (IC1) and sent to the speaker.
Refer to 2.3.4.4.1. Check Sheet
5. 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 (IC5) becomes
1, and this status is monitored by the ASIC (IC1).
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KX-FT25LA
Содержание KX-FT25LA
Страница 8: ...1 10 CCITT No 1 TEST CHART 8 KX FT25LA ...
Страница 9: ...1 11 LOCATION OF CONTROLS 1 11 1 OVERVIEW 9 KX FT25LA ...
Страница 10: ...1 11 2 CONTROL PANEL 10 KX FT25LA ...
Страница 13: ...1 13 3 SETTING YOUR LOGO 13 KX FT25LA ...
Страница 16: ...1 14 2 1 MAINTENANCE LIST 1 14 2 2 MAINTENANCE CYCLE 16 KX FT25LA ...
Страница 21: ...2 2 1 Document Jam 21 KX FT25LA ...
Страница 23: ...2 3 3 Simple Check List 23 KX FT25LA ...
Страница 24: ...2 3 4 TROUBLESHOOTING ITEMS TABLE 24 KX FT25LA ...
Страница 25: ...2 3 4 1 ADF Auto Document Feed Section 1 No document feed 25 KX FT25LA ...
Страница 26: ...2 Document JAM 26 KX FT25LA ...
Страница 28: ...4 Skew 28 KX FT25LA ...
Страница 29: ...5 Image is distorted When printing 29 KX FT25LA ...
Страница 30: ...6 Black or white vertical lines appear 7 Skewed receiving image 30 KX FT25LA ...
Страница 32: ...32 KX FT25LA ...
Страница 34: ...2 3 4 2 1 Defective facsimile section 1 Transmit problem 34 KX FT25LA ...
Страница 35: ...2 Sometimes there is a transmit problem 35 KX FT25LA ...
Страница 37: ...4 The unit can copy but cannot transmit receive 37 KX FT25LA ...
Страница 41: ...7 How to output the Journal Report 41 KX FT25LA ...
Страница 43: ...Countermeasure 43 KX FT25LA ...
Страница 44: ...44 KX FT25LA ...
Страница 45: ...45 KX FT25LA ...
Страница 46: ...46 KX FT25LA ...
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Страница 48: ...48 KX FT25LA ...
Страница 49: ...49 KX FT25LA ...
Страница 50: ...50 KX FT25LA ...
Страница 52: ...1 Entering the remote programming mode and changing service codes 52 KX FT25LA ...
Страница 56: ...2 3 4 3 1 Digital Block Diagram 56 KX FT25LA ...
Страница 58: ...Normal Wave Patterns 58 KX FT25LA ...
Страница 60: ...60 KX FT25LA ...
Страница 62: ...62 KX FT25LA ...
Страница 63: ...NG Example 63 KX FT25LA ...
Страница 66: ...Note Inside the digital board Inside the operation board 66 KX FT25LA ...
Страница 67: ...2 3 4 4 2 Defective ITS Integrated Telephone System Section 67 KX FT25LA ...
Страница 69: ...Refer to 2 3 4 4 Analog Board Section 69 KX FT25LA ...
Страница 71: ...2 Troubleshooting Flow Chart 71 KX FT25LA ...
Страница 72: ...72 KX FT25LA ...
Страница 74: ...2 3 4 6 Operation Board Section 1 No key operation 2 No LCD indication 74 KX FT25LA ...
Страница 76: ...2 3 4 8 Read Section Refer to 6 4 4 SCANNING BLOCK 76 KX FT25LA ...
Страница 77: ...77 KX FT25LA ...
Страница 78: ...2 3 4 9 Thermal Head Section Refer to 6 4 3 THERMAL HEAD 78 KX FT25LA ...
Страница 86: ...2 5 TEST FUNCTIONS 86 KX FT25LA ...
Страница 89: ...4 DISASSEMBLY INSTRUCTIONS 89 KX FT25LA ...
Страница 90: ...90 KX FT25LA ...
Страница 91: ...91 KX FT25LA ...
Страница 92: ...92 KX FT25LA ...
Страница 93: ...93 KX FT25LA ...
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Страница 95: ...95 KX FT25LA ...
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Страница 98: ...98 KX FT25LA ...
Страница 99: ...99 KX FT25LA ...
Страница 101: ...5 3 FLAT PACKAGE IC INSTALLATION PROCEDURE 5 4 BRIDGE MODIFICATION PROCEDURE 101 KX FT25LA ...
Страница 102: ...6 CIRCUIT OPERATIONS 6 1 CONNECTION DIAGRAM 102 KX FT25LA ...
Страница 104: ...6 2 1 General Block Diagram 104 KX FT25LA ...
Страница 105: ...6 3 CONTROL SECTION 6 3 1 BLOCK DIAGRAM 105 KX FT25LA ...
Страница 114: ...6 4 2 Block Diagram 114 KX FT25LA ...
Страница 116: ...116 KX FT25LA ...
Страница 121: ...6 4 6 3 2 Scanning 6 4 6 3 3 Printing Note See 6 5 SENSERS AND SWITCHES 121 KX FT25LA ...
Страница 122: ...6 4 6 3 4 Copying 122 KX FT25LA ...
Страница 131: ...b Redundancy Compression Process Coding Mode This unit uses one dimensional MH format 131 KX FT25LA ...
Страница 133: ...6 7 Analog Unit Block Diagram 133 KX FT25LA ...
Страница 137: ...6 10 2 Circuit Diagram 137 KX FT25LA ...
Страница 140: ...6 12 POWER SUPPLY BOARD SECTION 140 KX FT25LA ...
Страница 153: ...10 TERMINAL GUIDE OF THE IC S TRANSISTORS AND DIODES 153 KX FT25LA ...
Страница 154: ...11 FIXTURES AND TOOLS 154 KX FT25LA ...
Страница 155: ...12 CABINET MECHANICAL AND ELECTRICAL PARTS LOCATION 12 1 OPERATION PANEL SECTION 155 KX FT25LA ...
Страница 156: ...12 2 UPPER CABINET SECTION 156 KX FT25LA ...
Страница 157: ...12 3 LOWER CABINET P C B SECTION 157 KX FT25LA ...
Страница 159: ...12 5 ACTUAL SIZE OF SCREWS AND WASHER 159 KX FT25LA ...
Страница 160: ...13 ACCESSORIES AND PACKING MATERIALS 160 KX FT25LA ...