Huawei Airbridge BTS3612A-1900 Technical Manual page 26

Technical Manual
Airbridge BTS3612A CDMA Base Station
queried. It can also guarantee a safe and proper cooling system and lower the system
noise. Its main functions are as follows:
Control rotating speed of the fans.
Check whether fan units are in position and report their information.
Check and report fan unit blocking alarm.
Drive fan operating status indicator.
Communicate with the Main Control Unit (MCU) of BCKM and report in-board
status information.
II. Structure and principle
The position of BFMM is shown in Figure 2-9. And its function is shown in Figure 2-10.
Temperature collection module
Communication module
Fan-in-position & fault
Figure 2-10 Functions of BFMM
Power supply module
The power supply module converts +24V input power into the voltage required by
various modules of local board.
Main Control Unit (MCU)
The MCU controls the fans and communicates with the BCKM. That is:
- Generates control PWM signals according to the instruction sent from the BCKM to
control the speed of fans.
- Detects fan alarm signal and in-board logic alarm signal, and reports them to the
BCKM.
- Generates panel indicator signals.
Communication module
The module performs serial communication with the BCKM.
Fan driving module
detection module
Chapter 2 Baseband Subsystem
Main control unit
Power supply module
2-18
System Principle
Fan drive module
Switch value alarm module
Indicator drive module