2-11 
 
The following diagram shows the pins of the power socket connecting the power module and 
the mother board: 
 
 
Pin ID  Marking  Description 
1/3/5  12V  The positive output of the 12 VDC power 
2/4/6/8/10/ 
27/28/29/30 
GND  The output grounding terminal of the power board. 
7/9  3V3  The positive output of the 3.3 VDC power 
11  5V  The positive output of the 5 VDC power 
12  BC1  Signal indicating whether battery 1 is available. Low level indicates 
that battery 1 is available and high level indicates that battery 1 is 
not available.   
13/15  BAT+1  Input of battery 1, connecting to the positive pole of the battery.   
14  NTC1  Thermistor signal of battery 1.   
16  BC2  Signal indicating whether battery 2 is available. Low level indicates 
that battery 2 is available and high level indicates that battery 2 is 
not available.   
18  NTC2  Thermistor signal of battery 2. 
17/19  BAT+2  Input of battery 2, connecting to the positive pole of the battery. 
20  PCON  Power on/off control signal. It is a TTL pulse signal inputted from 
the back board. Every time when the power on/off switch is pressed 
(pulse of falling edge), a switch between power “on” and “off” 
happens. The pulse duration is no less than 0.1 s for power on, 2 s 
for power off and 10 s for illegal power off.     
21  BCON  Backlight on/off signal and switch output signal. The main board 
sends the LCD backlight on/off signals to the power board via a 
serial port, the power board processes the signals and output them. 
Low level is output when the backlight is off and high level is 
output when the backlight is on.   
22  LED-BAT  Battery status indication driving output 
23  LED-AC  AC power status indication signal 
24  LCD-BR  Backlight brightness control voltage.