User Manual
Airbridge cBTS3612 CDMA Base Station
System Description
2 Hardware Architecture
2-41
MCU
Communication
interface
Watchdog
HPAU
Interface
circuit
PWM
Modulation
circuit
Panel indicator
driving alarm
signal isolation
circuit
Temperature
collection
Serial port
BBFM
BHPA
External
temperature
collection
Fan cover
BTRM
Figure 2-22
Structure of BBFM module
l
MCU module
The MCU module collects and analyzes the temperature information to generate
PWM signal for controlling the fan speed, receives alarm signals generated by
BHPA module and fan alarm signals and reports to BTRM module, generates panel
indicator signal and communicates with BTRM module.
l
BHPA interface module
This moduloe isolates and drives the interface with BHPA.
l
Temperature information collection module
This module collects the temperature info rmation of BHPA module in real time,
which is implemented by MCU in query operation.
l
Panel indicator driving and alarm signal isolation module
It is used to drive the panel indicator and isolate fan alarm signals.
l
Communication module
The module performs serial communication with BTRM module.
l
Power supply module
The input power of BFMM is +27V, power consumption is 3.5W (including power for
the fans ).
3) Interface
l
BHPA interface
Interface with BHPA module, used for BHPA alarm monitoring.
l
Serial communication interface
Interface used to report the alarm of the fans and BHPA module.