Measurement And Remote Monitoring Technology Of The DMB Transmitter Operation Status

With the development of DMB technology,small-scale DMB system is increasingly applied.At present,the daily monitoring of DMB transmitter mainly relies on manual on-site inspection,so it cannot be monitored remotely,and it is difficult to timely reflect the running state of DMB transmitter,which brings inconvenience to the management and maintenance of DMB system.In view of the above problems,this paper studies the running state measurement technology of DMB transmitter,and designs a system that based on the LAN state parameter transmission and mobile terminal.Firstly,according to the structure and functional characteristics of DMB transmitter,the framework of DMB transmitter running state measurement and remote monitoring system is designed.The framework includes master control chip,temperature and humidity measurement,voltage measurement,current measurement,power measurement,data analysis and control,data transmission and other modules.Secondly,this paper completes the hardware design of the system.The main control chip adopts STM32.The temperature and humidity measurement module adopts the sensor DHT11,and realizes the temperature and humidity measurement in the signal modulator case through the single-bus protocol.The key voltage of signal modulator can be measured by an ADC.The meter chip ATT7053 BU and the shunt socket are adopted to isolate the strong power in the shunt socket to measure the power amplifier current.The power of the output signal of the power amplifier is distributed 1:100 by coupler,and the multistage logarithmic amplifier MAX2014 and the embedded ADC are used to measure.Switch of signal modulator controlled by relay;PE4302 programmed attenuator is adopted to adjust the transmitted signal power.The Ethernet controller W5500 is used to build the network environment.Then,the embedded software design of the above modules is completed,and the measurement results are analyzed comprehensively.When the voltage,current and other data abnormal,through the relay to close the signal modulator;When the power is greater than the threshold value,it is attenuated through PE4302 of program-controlled attenuator.In the data transmission module,based on embedded Web technology,a Web page that can interact with managers is designed,and the remote monitoring of DMB transmitter by computer and mobile terminal is realized.Finally,the measurement and control modules are tested.Humidity measurement error is 3%RH,voltage measurement error is 0.01 V,AC measurement error is 0.005 A,transmitting signal power measurement error is 0.5dBm.It can reduce the cost and meet the transmitter monitoring required measurement accuracy simultaneously.When the power is greater than the threshold value,it can give a remote alarm and automatically control PE4302,making the DMB transmitter work in the normal power range.When the temperature and humidity,voltage or current are abnormal,the automatic control relay can realize remote shutdown of the signal modulator and stop the transmitter.