User Manual
Airbridge cBTS3612 CDMA Base Station
System Description
2 Hardware Architecture
2-22
Main control unit
Power supply module
Temperature collection module
Communication module
Fan-in-position & fault
detection module
Fan drive module
Switch value alarm module
Indicator drive module
Figure 2-11
Illustration of BFMM
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Power supply module:
System input DC power is +27V, board power consumption is less than 5W.
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Main Control Unit (MCU):
MCU controls the fans and communicates with BCKM. Specifically, it generates
control PWM signal according to the instruction sent from BCKM to control the
speed of fans. MCU can also detect fan alarm signal and in-board logic alarm signal,
and report them to BCKM. It generates panel indicator signal.
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Communication module:
It performs serial communication with BCKM.
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Fan driving module:
PWM control signal generated in MCU provides controlled power input for fa ns by
isolating driving circuits.
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Fan in position and fault detection module:
This module isolates the fan-in-position signal and fan blocking alarm signal, then
convert them into logic level for MCU to sample and analyze.
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Temperature collection module:
The module collects the ambient temperature information of BFMM in real time,
which is realized by MCU in query operation.
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Indicator driving module:
When functional alarm (such as communication interruption in main control mode)
occurs to the board or fan blocking alarm occurs to the motor, this module provides
LED optical alarm interface inside the fan block, to drive the LED indicator on the
fan block front panel.