Panasonic KX-FT908RU-B / KX-FT908UA-B Service Manual ▷ View online
8.5.1. MOTOR POSITION SENSOR
This sensor is a detection switch for recording the position of the CAM.
Digital Board
Signal (IC1-119 Pin)
Home position
Low level
Other
High level
8.5.2. CUTTER POSITION SENSOR
Digital Board
Signal (IC1-131 Pin)
Home position
Low level
Other
High level
8.5.3. RECORDING PAPER SENSOR (SW1)
When there is no recording paper, the plate is separated from the switch lever and the switch turns off. Pin 63 of IC1 becomes a
high level. When there is recording paper, the plate pushes the switch lever and the switch turns ON. Pin 63 of IC1 becomes a low
level.
high level. When there is recording paper, the plate pushes the switch lever and the switch turns ON. Pin 63 of IC1 becomes a low
level.
Analog Board
Signal (CN1-63 Pin)
Paper
Low level
No paper
High level
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8.5.4. HOOK SWITCH (SW2)
When the handset is lifted, the switch turns ON, and the signal at pin 43 of IC1 becomes low.
When the handset is returned, the switch turns OFF, and the signal at pin 43 of IC1 becomes high.
Digital Board
SW
Signal
ON-Hook
OFF
High level (IC1-43 pin)
OFF-Hook
ON
Low level
8.5.5. JAM SENSOR (SW3)
The JAM sensor is a detection switch for determining whether the recording paper edge is in the correct position or not. If the
recording paper cannot be detected correctly at the JAM sensor position even when recording paper is present, then JAM is
displayed. If the recording paper is at the sensor position, then the switch turns on the IC1-21pin switches to a high level.
recording paper cannot be detected correctly at the JAM sensor position even when recording paper is present, then JAM is
displayed. If the recording paper is at the sensor position, then the switch turns on the IC1-21pin switches to a high level.
Analog Board
Signal (CN1-21 Pin)
Paper
Low level
No paper
High level
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8.5.6. DOCUMENT TOP SW (SW44)
When a document is brought to the read position, the SW becomes ON, and the input signal of IC1-16 pin (Operation) becomes
a low level. When there is no document at the read position, the SW becomes OFF, and the input signal of IC1-16 pin (Operation)
becomes a high level.
a low level. When there is no document at the read position, the SW becomes OFF, and the input signal of IC1-16 pin (Operation)
becomes a high level.
Operation Board
Signal (IC1-16 pin)
Out of the Read Position
High level
At the Read Position
Low level
8.5.7. DOCUMENT SET SENSOR (PS1)
When a document is set, the shelter plate closes the sensor light, the photo transistor becomes OFF, and the input signal of the
IC1-15 pin (Operation) becomes a high level. When there is no document, the shelter plate passes the sensor light, the photo
transistor becomes ON, and the input signal of the IC1-15 pin (Operation) becomes a low level. (When checking this sensor, the
IC1-41 pin becomes a low level.)
IC1-15 pin (Operation) becomes a high level. When there is no document, the shelter plate passes the sensor light, the photo
transistor becomes ON, and the input signal of the IC1-15 pin (Operation) becomes a low level. (When checking this sensor, the
IC1-41 pin becomes a low level.)
Operation Board
Photo transistor
Signal (IC1-15 Pin)
No document
ON
Low level
Set document
OFF
High level
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8.6. MODEM SECTION
8.6.1. FUNCTION
The unit uses a 1 chip modem (IC5), enabling it to act as an interface between the control section for FAX sending and
receiving, and the telephone line. During a sending operation, the digital image signals are modulated and sent to the telephone
line. During a receiving operation, the analog image signals which are received via the telephone line are demodulated and
converted 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 and
DTMF.
receiving, and the telephone line. During a sending operation, the digital image signals are modulated and sent to the telephone
line. During a receiving operation, the analog image signals which are received via the telephone line are demodulated and
converted 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 and
DTMF.
It can be controlled by writing commands from the ASIC (IC1) to the register in the modem (IC5).
This modem (IC5) also sends DTMF signals, and detects busy tones, dial tones and DTMF.
Overview of Facsimile Communication Procedures (ITU-T Recommendation):
1. ON ITU-T (International Telecommunications´ Union.)
The No. XIV Group of ITU-T, one of the four permanent organizations of the International Telecommunications Uniib (ITU),
investigates and make recommendations on international standards for facsimiles.
investigates and make recommendations on international standards for facsimiles.
2. Definition of Each Group
·
Group I (G1)
A-4 size documents without using formats which reduce the band width of a signal sent over telephone lines.
Determined in 1968.
Determined in 1968.
Transmission for about 6 minutes at 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
density of 3.85 lines/mm for about 3 minutes.
Methods to suppress redundancy are not used.
Determined in 1976.
density of 3.85 lines/mm for about 3 minutes.
Methods to suppress redundancy are not used.
Determined in 1976.
·
Group III (G3)
A method of suppressing redundancy in the image signal prior to modulation is used. An A-4 size document is sent with
about one minute.
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.
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.
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