Mindray DC-25, Руководство по обслуживанию

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Hardware Principle 4-13
4.5 Control Panel
St atus
indicator *5
TGC board Trackball
Functional
button
Single-
encoder
board
Key
scan
LED backlight drive
circuit
Key LED
backlight
USB
port chip
ADC circuit
Buzzer
Buzzer drive circuit
Main
controller
Trackball
scan
TGC
scan
PWM generating
circuit
FPGA
Control panel
PCBA
IO
interfac
e board
USB
+12V,+5V
Dual-
encoder
board
Port connecting
Control panel wit h IO
connecting board
Figure 4-13 Principle Diagram of the Control Panel
The control panel
PCBA
is the core of the control panel which comprises control panel PCBA,
trackball, TGC board, encoder board and buzzer.
Functions are
：

FPGA is regarded as a main controller of the control panel, keys,
single/dual-encoder, trackball and TGC are scanned by FPGA; key LED
backlight and buzzers are both controlled by FPGA, and only when FPGA is
normal can key LED backlight be on.

Five indicators on the control panel are directly drived from interior of main unit.

The control panel communicates with the CPU module by USB ports.