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KX-FT981LA-B / KX-FT987LA-B
6.6.
Modem Section
6.6.1.
Function
The unit uses a 1 chip modem (IC5) that serves as an interface between the control section for FAX transmission and reception
and the telephone line. During a transmitting operation, the digital image signals are modulated and sent to the telephone line.
During a receiving operation, the analogue image signals which are received via the telephone line are demodulated and con-
verted into digital image signals. The communication format and procedures for FAX communication are standardized by ITU-T.
This 1 chip modem (IC5) has hardware which sends and detects all of the necessary signals for FAX communication (DTMF).
It can be controlled by writing commands from the CPU (IC1: inside ASIC) to the register in the modem (IC5).
This modem (IC5) also sends DTMF signals, generates a call tone (from the speaker), and detects a busy tone and dial tones.
Overview of Facsimile Communication Procedures (ITU-T Recommendation):
1.
ON CCITT (International Telegraph and Telephone Consultative Committee)
The No. XIV Group of CCITT, one of the four permanent organizations of the International Telecommunications Union (ITU),
investigates and make recommendations on international standards for facsimiles.
2.
Definition of Each Group
• Group I (G1)
Official A-4 size documents without using formats which reduce the band width of a signal are sent over telephone lines.Deter-
mined in 1968.
Transmission for about 6 minutes at a scanning line density of 3.85 lines/mm.
• Group II (G2)
Using reduction technology in the modulation/demodulation format, an A-4 size document is sent at an official scanning line den-
sity of 3.85 lines/mm for about 3 minutes.
Methods to suppress redundancy are not used.
Determined in 1976.
• Group III (G3)
Method of suppressing redundancy in the image signal prior to modulation is used. An A-4 size document is sent within about
one minute.
Determined in 1980.
• Group IV (G4)
Transmission is via the data network. A method is provided for suppressing redundancy in signals prior to transmission, and
error-free reception of transmission is possible.
The scope of these facsimile applications is not limited simply to transmission of written statements. Through symbiotic linkages
with other communication methods, it can be expected to expand to include integrated services.
Summary of Contents for KX-FT981LA-B
Page 11: ...11 KX FT981LA B KX FT987LA B 6 Technical Descriptions 6 1 Connection Diagram ...
Page 13: ...13 KX FT981LA B KX FT987LA B 6 2 1 General Block Diagram ...
Page 21: ...21 KX FT981LA B KX FT987LA B 6 4 2 Block Diagram ...
Page 23: ...23 KX FT981LA B KX FT987LA B ...
Page 63: ...63 KX FT981LA B KX FT987LA B 11 2 2 User Mode KX FT987 ...
Page 71: ...71 KX FT981LA B KX FT987LA B Countermeasure ...
Page 72: ...72 KX FT981LA B KX FT987LA B REFERENCE Test Mode P 54 ...
Page 73: ...73 KX FT981LA B KX FT987LA B REFERENCE Test Mode P 54 ...
Page 74: ...74 KX FT981LA B KX FT987LA B REFERENCE Test Mode P 54 ...
Page 75: ...75 KX FT981LA B KX FT987LA B REFERENCE Test Mode P 54 ...
Page 76: ...76 KX FT981LA B KX FT987LA B ...
Page 77: ...77 KX FT981LA B KX FT987LA B ...
Page 78: ...78 KX FT981LA B KX FT987LA B REFERENCE Test Mode P 54 ...
Page 82: ...82 KX FT981LA B KX FT987LA B ...
Page 108: ...108 KX FT981LA B KX FT987LA B NG Wave pattern Note Refer to NG Example P 113 ...
Page 110: ...110 KX FT981LA B KX FT987LA B I O and Pin No Diagram ...
Page 113: ...113 KX FT981LA B KX FT987LA B 12 5 6 2 NG Example ...
Page 115: ...115 KX FT981LA B KX FT987LA B ...
Page 120: ...120 KX FT981LA B KX FT987LA B 12 5 9 2 Troubleshooting Flow Chart ...
Page 126: ...126 KX FT981LA B KX FT987LA B 12 5 13 Thermal Head Section Refer to Thermal Head P 22 ...
Page 127: ...127 KX FT981LA B KX FT987LA B 13 Service Fixture Tools ...
Page 130: ...130 KX FT981LA B KX FT987LA B 14 1 2 How to Remove the Cutter Unit KX FT987 only ...
Page 131: ...131 KX FT981LA B KX FT987LA B 14 1 3 How to Remove the Lock Lever and Thermal Head ...
Page 133: ...133 KX FT981LA B KX FT987LA B 14 2 2 How to Remove the P C Boards and Power Cord ...
Page 136: ...136 KX FT981LA B KX FT987LA B 14 3 2 How to Remove the Operation Board LCD and Platen Roller ...
Page 137: ...137 KX FT981LA B KX FT987LA B 14 3 3 How to Remove the Separation Rubber Flap ...
Page 138: ...138 KX FT981LA B KX FT987LA B 14 4 Installation Position of the Lead Wires ...
Page 139: ...139 KX FT981LA B KX FT987LA B ...
Page 147: ...147 KX FT981LA B KX FT987LA B 15 2 3 4 Copying REFERENCE Sensor Section P 123 ...
Page 152: ...152 KX FT981LA B KX FT987LA B 16 1 4 Power Supply Board ...
Page 154: ...154 KX FT981LA B KX FT987LA B 16 3 Test Chart 16 3 1 ITU T No 1 Test Chart ...
Page 155: ...155 KX FT981LA B KX FT987LA B 16 3 2 ITU T No 2 Test Chart ...
Page 168: ...168 KX FT981LA B KX FT987LA B MEMO ...
Page 178: ...178 KX FT981LA B KX FT987LA B 20 1 1 Operation Panel Section KX FT981 ...
Page 179: ...179 KX FT981LA B KX FT987LA B 20 1 2 Operation Panel Section KX FT987 ...
Page 180: ...180 KX FT981LA B KX FT987LA B 20 1 3 Upper Cabinet Section ...
Page 181: ...181 KX FT981LA B KX FT987LA B 20 1 4 Lower Cabinet Section ...
Page 182: ...182 KX FT981LA B KX FT987LA B 20 1 5 Gear Block Section ...
Page 183: ...183 KX FT981LA B KX FT987LA B 20 1 6 Screws ...
Page 184: ...184 KX FT981LA B KX FT987LA B 20 1 7 Accessories and Packing Materials ...
Page 192: ...192 KX FT981LA B KX FT987LA B K N KXFT981LAB KXFT987LAB ...