Panasonic KX-FT25LA Service Manual ▷ View online
6.5.3. Read Position Sensor (PS2)
When a document is brought to the read position, the shelter plate passes the sensor light, the photo transistor becomes ON, and
the input signal of the CN2-5 pin (Operation) becomes a low level. When there is no document at the read position, the shelter plate
closes the sensor light, the photo transistor becomes OFF, and the input signal of the CN2-5 pin (Operation) becomes a high level.
(When checking this sensor, CN1-8 pin, 2pin becomes low level).
the input signal of the CN2-5 pin (Operation) becomes a low level. When there is no document at the read position, the shelter plate
closes the sensor light, the photo transistor becomes OFF, and the input signal of the CN2-5 pin (Operation) becomes a high level.
(When checking this sensor, CN1-8 pin, 2pin becomes low level).
Operation Board
Photo transistor
Signal (CN2-5 Pin)
Out of the Read Position
OFF
High level
At the Read Position
ON
Low level
6.5.4. Document 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
CN2-5 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 CN2-5 pin (Operation) becomes a low level.
CN2-5 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 CN2-5 pin (Operation) becomes a low level.
(When checking this sensor, the CN1-8 pin, 3pin becomes a low level.)
Operation Board
Photo transistor
Signal (CN2-5 Pin)
No document
ON
Low level
Set document
OFF
High level
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6.6. MODEM SECTION
6.6.1. 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.
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 (IC5) to the register in the modem (IC5).
This modem (IC5) also sends DTMF signals, generates a call tone (from the speaker), and detects busy tones, dial tones and
DTMF.
DTMF.
Overview of Facsimile Communication Procedures (CCITT Recommendation):
1. ON ITU-T (International Telecommunications´ Union.)
The No. XIV Group of CCITT, 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.
3. Facsimile Call Time Series
As shown in the following diagram, the facsimile call time series is divided into five phases.
Phase A : Call setting
Call setting can be manual/automatic.
Phase B : Pre-message procedure
Phase B is a pre-processing procedure and sequence for confirming the status of the terminal, transmission route, etc. and for
terminal control. It implements the terminal preparation status, determines and displays terminal constants, confirms
synchronization status, etc. and prepares for transmission of facsimile messages.
terminal control. It implements the terminal preparation status, determines and displays terminal constants, confirms
synchronization status, etc. and prepares for transmission of facsimile messages.
Phase C : Message transmission
Phase C is the procedure for transmitting facsimile messages.
Phase D : Post message procedure
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Phase D is the procedure for confirming that the message is completed and received. For continuous transmission, phase B
or phase C are repeated for transmission.
or phase C are repeated for transmission.
Phase E : Call retrieval
Phase E is the procedure for call retrieval, that is for circuit disconnection.
4. Concerning Transmission Time
Transmission Time
= Control Time
+ Image Transmission Time
+ Hold Time
Transmission time consists of the following.
Control time:
This is time at the start of transmission when the functions at the sending and receiving sides are confirmed, the
transmission mode is established, and transmission and reception are synchronized.
transmission mode is established, and transmission and reception are synchronized.
Image transmission time:
This is the time required for the transmission of document contents (image data). In general, this time is recorded in the
catalog, etc.
catalog, etc.
Hold time:
This is the time required after the document contents have been sent to confirm that the document was in fact sent, and to
check for telephone reservations and/or the existence of continuous transmission.
check for telephone reservations and/or the existence of continuous transmission.
5. Facsimile Standards
Item
Telephone Network Facsimile
G3 Machine
Connection Control Mode
Telephone Network Signal Mode
Terminal Control Mode
T. 30 Binary
Facsimile Signal Format
Digital
Modulation Mode
PSK (V. 27 ter) or QAM (V. 29)
Transmission Speed
300 bps (Control Signal)
2400, 4800, 7200, 9600 bps (FAX Signal)
2400, 4800, 7200, 9600 bps (FAX Signal)
Redundancy Compression
Process
(Coding Mode)
Process
(Coding Mode)
1 dimension: MH Mode
2 dimension: MR Mode (K=2.4)
2 dimension: MR Mode (K=2.4)
Resolution
Main Scan: 8 pel/mm
Sub Scan: 3.85, 7.7l/mm
Sub Scan: 3.85, 7.7l/mm
Line Synchronization Signal
EOL Signal
1 Line Transmission Time
[ms/line]
[ms/line]
Depends on the degree of data reduction.
Minimum Value: 10, 20
Can be recognized in 40ms.
Minimum Value: 10, 20
Can be recognized in 40ms.
6. Explanation of Technology
a. G3 Communication Signals (T. 30 Binary Process)
For G3 facsimile communication, this is the procedure for exchanging control signals between the sending and receiving
machines both before and after transmission of image signals.
Control signals at 300 bps FSK are: 1850 Hz...0, 1650Hz...1.
An example of the binary process in G3 communication is shown below.
machines both before and after transmission of image signals.
Control signals at 300 bps FSK are: 1850 Hz...0, 1650Hz...1.
An example of the binary process in G3 communication is shown below.
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Explanation of Signals
Control signals are comprised mainly of 8-bit identification signals and of the data signals added to them. Data signals are
added to DIS and DCS signals.
added to DIS and DCS signals.
Signal.....DIS (Digital Identification Signal)
Identification Signal Format.....00000001
Identification Signal Format.....00000001
Function:
Notifies the capacity of the receiving unit. The added data signals are as follows.
Notifies the capacity of the receiving unit. The added data signals are as follows.
(Example)
Bit No.
DIS/DTC
DCS
1
Transmitter - T.2 operation
2
Receiver - T.2 operation
Receiver - T.2 operation
3
T.2 IOC = 176
T.2 IOC = 176
4
Transmitter - T.3 operation
5
Receiver - T.3 operation
Receiver - T.3 operation
6
Reserved for future T.3 operation features.
7
Reserved for future T.3 operation features.
8
Reserved for future T.3 operation features.
9
Transmitter - T.4 operation
10
Receiver - T.4 operation
Receiver - T.4 operation
11, 12
(0, 0)
(0, 1)
(1, 0)
(1, 1)
(0, 1)
(1, 0)
(1, 1)
Data signaling rate
V.27 ter fall back mode
V.27 ter
V.29
V.27 ter and V.29
V.27 ter fall back mode
V.27 ter
V.29
V.27 ter and V.29
Data signaling rate
2400 bit/s, V.27 ter
4800 bit/s, V.27 ter
9600 bit/s, V.29
7200 bit/s, V.29
2400 bit/s, V.27 ter
4800 bit/s, V.27 ter
9600 bit/s, V.29
7200 bit/s, V.29
13
Reserved for the new modulation system.
14
Reserved for the new modulation system.
15
Vertical resolution = 7.7 line/mm
Vertical resolution = 7.7 line/mm
16
Two-dimensional coding capability
Two-dimensional coding
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