2-6  
 
2.3.2 Output System   
 
LCD 
The patient monitor adopts a high-resolution LCD. The LCD is connected with the main 
board. The signals and power supply from the backlight board are transferred by the button 
board.  
 
 
Alarm Lamp 
The patient monitor has two alarm lamps: alarm lamp and technical alarm lamp. Alarm lamp 
lights either red or yellow whereas technical alarm lamp lights blue only. The alarm lamp 
signals are transferred by the button board and are directly controlled by the main board   
 
 
Recorder 
The recorder receives data form the main board and then sends them to the thermal printhead 
for printing. The recorder has a hardkey (starting/stopping recordings) and a green LED on its 
front panel. It is connected with the mother board. 
 
The following diagram shows its operating principle.