Panasonic UF-590 / UF-790 / DX-600 / DX-800 Service Manual / Other ▷ View online
17
1.1.8
Line Control Circuit
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.
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
(IC23)
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
Control
I/F
Si3021
MODEM
MN195006
CPU
PNL
10MW
Line Control Circuit
MJR PCB
SC PCB
(IC24)
18
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 PC Board controls all dial
pulse generation sequences. When the absence of the terminating message is confirmed by the Off-Hook
detector in DAA (IC23), 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.
peripheral circuits. The generator generates dial pulses. The CPU on the SC PC Board controls all dial
pulse generation sequences. When the absence of the terminating message is confirmed by the Off-Hook
detector in DAA (IC23), 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 PC Board. The DTMF tone is con-
veyed to the telephone line using the same route as the facsimile signal. The DTMF tone selection is con-
trolled by the CPU. Digital amplitude signal is conveyed as analog amplitude signal through D/A converter
in the DAA (IC23). The line status during dialing is shown below.
veyed to the telephone line using the same route as the facsimile signal. The DTMF tone selection is con-
trolled by the CPU. Digital amplitude signal is conveyed as analog amplitude signal through D/A converter
in the DAA (IC23). The line status during dialing is shown below.
Ring Detector
When the unit is in the Sleep Mode status, a Ringing signal is detected by a photo-coupler (PC2) in Ring
Detector to cancel the power-save for waking up. Then DAA (IC23) detects the ringing signal for receive
mode.
When the unit is normal operating status, DAA (IC23) detects the ringing signal immediately.
Detector to cancel the power-save for waking up. Then DAA (IC23) detects the ringing signal for receive
mode.
When the unit is normal operating status, DAA (IC23) detects the ringing signal immediately.
CML Relay
Dial Pulse
Generate Circuit
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
19
1.1.9
SNS PC Board
Each sensor consists of an LED and photo transistor. When documents are placed on the ADF tray or are
moving, a shutter in the document sensor opens. The light from the LED turns the photo transistor “ON”,
and the output voltage from the sensor becomes a “Low” level. With no document on the ADF tray, the shut-
ter interrupts the light path, and output from the sensor is kept at a “High” level. Operation of the RP Sensor
is exactly the same as the ADF Sensor. The ADF Cover Sensor operation is similar, except that the output
from the sensor is kept at a “Low” level when the cover is closed and becomes a “High” level when the
Printer Cover is opened.
moving, a shutter in the document sensor opens. The light from the LED turns the photo transistor “ON”,
and the output voltage from the sensor becomes a “Low” level. With no document on the ADF tray, the shut-
ter interrupts the light path, and output from the sensor is kept at a “High” level. Operation of the RP Sensor
is exactly the same as the ADF Sensor. The ADF Cover Sensor operation is similar, except that the output
from the sensor is kept at a “Low” level when the cover is closed and becomes a “High” level when the
Printer Cover is opened.
Read Point
Sensor
Sensor
GND
+5V
+5V
nBPNT
PC3
Shutter
A
K
ADF Cover Sensor
(ILS PC Board)
MPU
CPU
(IC1)
Shutter
PC2
A
K
ADF
Sensor
Sensor
GND
PC1
Shutter
A
K
SC PC Board
PNL1 PC Board
+5VP
+5VP
PNL CPU
IC1
20
1.1.10
Control Panel
The Control Panel consists of the Display PCB and Panel Unit, which display various status information.It is
normally interfaced to the main CPU. Keyed input signals are received by the Panel CPU and the data is
transferred to the main CPU on the SC PC Board.
The Control Panel performs the following processes simultaneously:
normally interfaced to the main CPU. Keyed input signals are received by the Panel CPU and the data is
transferred to the main CPU on the SC PC Board.
The Control Panel performs the following processes simultaneously:
• Key inputting
• LED, LCD display
• Data transmission / reception
• LED, LCD display
• Data transmission / reception
Interface to main CPU
The interfacing between the main CPU and the panel CPU are all executed with commands and responses
in the following two formats:
The interfacing between the main CPU and the panel CPU are all executed with commands and responses
in the following two formats:
• Command / response (1 byte) + number of data + check sum
• Command / response (1 byte) + number of data + data 1 + data 2........................ + data n + check sum.
• Command / response (1 byte) + number of data + data 1 + data 2........................ + data n + check sum.
PNLCK
PNLRD
PNLSD
PNLRST
BZCLK
+5V
+5VP
GND
GND
nPWSAVE
nWAKEUP
nBPNT
BATLVL
20 characters, 2 lines, 5x7 dots control
LED, KEY scanning
LED, KEY scanning
2
8
8
8
SCN (7:0)
KIN (7:0)
LED
Key matrix
(59 keys)
(59 keys)
PNL1 PC Board
11
LED (1:0)
LEDCT (1:0)
From
/to
SC
PCB
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