Operation Panel Circuit - Citizen CL-S400DT Technical Manual

(4) Operation panel circuit

The following is the simplified operation panel circuit. The circuit consists of 1 LED
(Green/Red), 4 switches and 1 LCD.
The LCD is controlled by the signals send from the FPGA (U11). The backlight of LCD is
controlled by BKL-W (White) and BKL-O (Orange) signals sent from the CPU (U1A).
The signals output from the switches are sent to the CPU (U1A).
Green color (POWER indication) and red color (Error indication) of the LED are controlled by
the signal sent from the CPU (U1A).
When PWRSAVE (power saving) signal sent from the CPU (U1A) is "Low", Q27 and Q28 turn
OFF and +3.3V supply to the LCD is shut off. (Power saving mode is effective if the "Standby
Mode" submenu under the "System Setup" main menu is set to "On". However, the "Standby
Mode" is set to "Off" at factory default.)
Power Saving Mode
L: Power saving mode ON (+3.3V OFF)
H: Normal mode (+3.3V ON)
From
PWRSAVE
U1A
CPU
R126
+5V
From
U11 (FPGA)
From/to
U1A (CPU)
[SA Main PCB]
+3.3V
R151
Q27
DTC115EM
Q26
MCH3333
J3
J301
17 1
+3.3V
16 2
+5V
LCDSI 15 3
LCDSCK 14
4
13 5
LCDCD
4
4
12
6
LCDRST
nLCDCS 11
7
BKL-W
10
8
BKL-O 9
9
10
SW0 8
SW1 11
7
6 12
SW2
13
SW3 5
14
LED-G 4
LED-R
3
15
2 16
1 17
[SA LCD PCB]
Q301
DTC114EM
BKL-WHITE
BKL-ORANGE
Q304
DTC114EM
+3.3V
SW302
SW301
SW303
SW304
Q302
DTC114EM
Q303
DTC114EM
2-25
Chapter 2 Operating Principles
2-2. Operation of Control Parts
+5V
PAD301
Anode
PAD302
LCD
Cathode
Backlight
(White)
PAD303
Cathode
(Orange)
J302
LCD
PAUSE
FEED
STOP
MENU
+5V
Power LED
Green (Power)
Red (Error)
D301
CL-S400DT