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29

The Line Control Circuit consists of CML relay, DP circuit, DAA (Direct Access Arrangement), Ring Detect 
Circuit for power-save and DC hold circuit. A Jack for an external telephone, which can be used for either 
an external telephone or an optional Handset Kit. The block diagram of the Line Control Circuit is shown 
below.

DP Control

Ringer Signal Detection,

TAM I/F,

DTMF Remote Detection

Off-Hook

Detection

Speech

IC

DAA

Line

I/F

Si3015

(IC12)

DP

Circuit

DC Hold

Circuit

Ringer Signal

Detector

for Wake-up

(PC2)

Ringer

IC

+
-

~
~

Hook SW

External

Telephone

Jack

Connect only to

one module

Line

CML Relay

Optional Handset Kit

+
-

~
~

DAA

Ccontrol

I/F

Si3021

MODEM

MN195006

CPU

PNL

10MW

Line Control Circuit

30

Dial Pulse Generator
The Dial Pulse Generator consists of a CML relay, a DC hold circuit, a dial pulse generate circuit and their 
peripheral circuits. The generator generates dial pulses. The CPU on the SC Board controls all dial pulse 
generation sequences. When the absence of the terminating message is confirmed by the Off-Hook 
detector in DAA (IC12), the CPU turns the CML relay ON and the dial pulse generate circuit ON through 
DAA to develop loop status (DC loop). After a few seconds, the CPU turns the PLS relay ON and OFF to 
generate dial pulses, making and breaking the loop. The line status during dialing is shown below.

DTMF Tone Generator
The DTMF Tone Generator is incorporated in the MODEM on the SC Board. The DTMF tone is conveyed to 
the telephone line using the same route as the facsimile signal. The DTMF tone selection is controlled by 
the CPU. Digital amplitude signal is conveyed as analog amplitude signal through D/A converter in the DAA 
(IC12). The line status during dialing is shown below.

he unit is normal operating status, DAA (IC12) detects the ringing signal immediately.

CML Relay

Dial Pulse
Generate Circuit

Line status

break

make

make

break

Line release

Speech

condition

First

digit

make

break

Prepause

Inter-digit

pause

Speech

condition

Speech

condition

Second

digit

CML Relay

Line status

break

make

Line release

Speech

condition

First

digit

make

break

DTMF signal

Signal time

Inter-digit

pause

Speech

condition

Second

digit

Speech

condition

31

< Check Output : If Signal is not correct, each IC

                          may be defective >

Initial Flow

Power ON

Hardware Reset

Boot Program in CPU Start

0

Is Cover Open CPU (73) and

BPNT CPU (44) are Low ?

Wait Data from PC

via Parallel I/F

Update Program

Scanning LED Lit &
Scanning LED Flashed

CPU I/O Port Set

I/O Device Reset

I/O Device Port Set

System Program (FROM) Start

SDRAM Working Area Clear

PANEL Initial

1

UF-490 (xx)

Below is displayed on LCD

< Check Output : If Signal is not correct, each IC

                            may be defective >

Power

Matser

Clock

Reset

CNP4.5 3.3V -> IC1 CPU, IC3 SHINE
CNP4.7 5V -> (3) IC4 (4) 2.5V -> IC3 SHINE

5MHz -> (63) CPU (90) 50MHz
-> (103) IC3 SHINE

Reset IC2 (4) ->       -> (32) IC3 SHINE (39)
->       -> (59) IC1 CPU

XTAL

3V

0V

3.3V

0V

CPU (CS0)

IC1 CPU (107) ->        -> (26) IC5 FROM

CPU (RD)

IC1 CPU (95)   ->        -> (28) IC5 FROM

CPU (A1-21)

IC1 CPU (142-118) ->        -> (26) IC5 FROM

CPU (D0-D15)

IC1 CPU (114,17-1) ->        -> (26) IC5 FROM

nMDMRST

IC1 CPU (84) ->        -> (41) IC9 Modem

nFRPRST

IC1 CPU (83)   ->        -> (44) IC18 FRIP

CPU (PNLTXD)

IC1 CPU (67) ->        -> CNP5.5

CPU (PNLRXD) IC1 CPU (66) ->        -> CNP5.6

CPU (PNLRST) IC1 CPU (85) ->        -> CNP5.9

5V

0V

< Check Output : If Signal is not correct, each IC
                            may be defective >

< Check Output : If Signal is not correct, each IC

                           may be defective >

...

3.3V

0V

...

N

Y

32

Initialize Flow 2

Back up Data Recover

Task Initialize

1

Back up Data

PARITY ERROR ?

Shipment Set

saves System Data to FROM

Confirmation of timer, POWER OFF/ON,...

JOB Recover, if required

DISPLAY ERROR

0

SCANNER Initialize

PRINTER Initialize

# CAUTION #
Do white shading when Parity Error occurs.
(Service Mode 5-6)

SCANNER Error ?

PRINTER Error ?

N

Y

Y

DISPLAY DATE & TIME

N

23-OCT 19:14 00%

ADF OPEN     061

DOCUMENT JAM 031

CHECK PRINTER 054

(Ex.) Parameter of FROM. etc...

Task initialize for Software.

Back up data in FROM IC5 ->
Parameter, Journal,...