DOWNLOAD Panasonic KX-FLB813RU Service Manual ↓ Size: 15.59 MB | Pages: 127 in PDF or view online for FREE

25

Composed of ITS circuit and NCU circuit.

The cross-point switch installed in this IC makes it possible to change the circuit configuration
for any analog signals such as the fax signals sent from the digital board. In addition, 
this analog gate array integrates a handset circuit, input/output ports, etc.
This IC is controlled by SOC (IC600) through GATE ARRAY (IC604) on the digital board.

Explanation of ANALOG GATE ARRAY (IC209 on the ANALOG Board)

No.

Name

Function

No.

Name

Function

1

STR

Strobe input

19

NC

Not used

2

CLOCK

Clock input

20

EXTIN

Ext amp output

3

DATA

Data input

21

EXTOUT

Ext amp input

4

VDD

Logic power supply 

22

LINEOUT

Line amp output

5

VOXOUT

VOX output

23

LINEIN

Line amp input

6

VOXDET

VOX detection adjustment

24

MODEMTXIN

MODEM TX amp input

7

VOXIN

VOX input

25

MODEMTXOUT

MODEM TX amp output

8

VSS

Logic ground

26

NC

Not used

9

NC

Not used

27

TONEIN

Tone amp input

10

ROUT2

HS receiver amp output 2

28

NC

Not used

11

ROUT1

HS receiver amp output 1

29

NC

Not used

12

RIN

HS receiver amp input

30

GND

Analog ground

13

VCC

Analog ground

31

MODEMRXOUT

MODEM RX amp output

14

HSMICIN1

HS mic amp input 1

32

VLIN

Volume amp input

15

HSMICIN2

HS mic amp input 2

33

VREF

Reference voltage output

16

HSMICOUT

HS mic amp output

34

VLOUT

Volume amp output

17

NC

Not used

35

SPOUT

Speaker amp output

18

NC

Not used

36

SPIN

Speaker amp input

26

Function
The analog section works as an interface between the telephone line.
The analog ASIC (IC209) on the analog board exchanges FAX TX and RX signals between the MODEM (IC607) and the analog
section.
The control signals transmitted to the analog section are output mainly from G/A IC604, and the analog status is stored as data
in G/A IC604. 

Circuit Operation
[NCU]: Network Control Unit the NCU comprises of the following; DC loop forming circuit to connect with the telephone line;
Switching circuit for other interconnected telephones; Bell detection circuit; Side tone circuit; Remote fax activation circuit.
Refer to NCU SECTION (P.34) for the details.

27

T

R

T

R

LINERL

Y

CIDRL

Y

Bell1

Break1

HSalc1

P-shor

t1

DTMF Receiv

er

25

26

29

32

TXM

TXP

RX

HSMIC

INPUT

MLA

T

M

D

ATA

MCLK

ASIC SPOUT

HOOK

0/-6

A 5

A 4

A 3

A 2

A 1

D

0/-6

MUTE2

MUTE1

0/-1/-2/-3/-4/-5/6/7/8

0/-3

-20/-30

0/-6/-12

DET

20

EV

OL0

EV

OL2

EV

OL1

T

ONE

VO

X

Modem(Python)

TXM

TXP

RX

HSMIC

4

3

2

11

6

15

14

13

12

11

10
9

8

7

6

51

8

17

21

22

23

24

25

26

27

28

29

30

19

20

31

32

33

34

35

36

1

1

0

9

6

1

4

1

25

26

29

32

1

KX-FLB813R

U ANALOG BO

ARD:BLOCK DIA

GRAM

28

The unit uses MODEM (IC600) 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 analog 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.
MODEM has hardware which sends and detects all of the necessary signals for FAX communication. 
It can be controlled by writing commands from the SOC (IC600).
This MODEM 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 ITU-T, 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.
Determined 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
density 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 link-
ages 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 terminal preparation status, determines and displays terminal constants, confirms synchro-
nization status, etc. and prepares for transmission of facsimile messages. 
Phase C: Message transmission 
Phase C is the procedure for the transmitting facsimile messages.
Phase D: Post message procedure 
Phase D is the procedure for confirming that the message is completed and received. For continuous transmission, phase B
or phase C is repeated for transmission. 
Phase E: Call retrieval 
Phase E is the procedure for call retrieval, that is for circuit disconnection.