1、Zigbee sensors collect a variety of parameters passed to the trenches of the gateway, then the gateway by wireless data transmission to the central control computer, analysis and comparison the data by computer, to assess the security situation in the mine.
1. Data Collection Terminal
Terminal equipment is mainly composed of all kinds of sensors, alarm and Zigbee module. The sensor is consist of two part, one is used at environmental monitoring: including gas concentration detected, carbon monoxide concentrations detection, air humidity detector, and
so on; the other is the collection of vital signs for miners: such as pulse, blood pressure, respiratory, body temperature, including pulse sensor, temperature sensor and state sensors, etc.
2. Wireless transmission equipment
Zigbee F8914 connected to the data collection terminal in the mine via RS232/485. F8914 acts as the terminal node, which can receive and send information but not communication between terminal nodes.
Zigbee center node uses F8114 Zigbee+GPRS module,and center node can send data to server via RS232( the node and server is closer),or via GPRS network (the node is far away from server). Both of them are transparent data transmission.
3. the topology of F8914-----F8114
F8914 connected to the data collection terminal ( sensor or PLC) via RS232/485,then receive data from data collection terminal, and will send data to F8114(center node) via 2.4G Zigbee network.At last, F8114 sends the data to server via RS232 or GRPS network.
The software analyses the data in the server,and the result will be sent to the terminal(sensor ro PLC),so we can control the terminal (sensor or PLC) via server.
1、Transmission module by wireless GPRS network，GPRS network has operations in the country for over ten years currently(network stable, mature technology, wide coverage).
2、Transmission module using industrial ZigBee module,standard band: IEEE802.15.4 ISM2.4GHz,communication distance:90m,outdoor communication distance:800m,transmit power:22dBm,receiver sensitivity:-104dBm,low-power design,support multi-level sleep and wake up,Built-in real-time clock（RTC）,Support the timer switch function,time off state power consumption less than 1mA.standard power:DC 12V/500mA,Current Communication:50mA-80mA@12VDC、115-150mA@5VDC,STBY:20mA@12VDC、35mA@5VDC,Sleeping station:8mA@12VDC、18mA@5VDC,operating temperature:-25~+65ºC,storage temperature:-40~+85ºC,relative humidity:95%(non-condensing),Multiple hardware and software design watchdog,Suitable for outdoor work environment.
3、Transmission module has a reliable network connection,Intelligent anti-dropped,support on line testing,Online maintenance,Dropped automatically reboot,Ensure the equipment is always on line,ensure the normal communication channels,Provide data for the data center.
4、Terminal transmission module supports a variety of activation,Such as voice calls, SMS, data, etc.Terminal equipment failure or abnormal,Automatically send text messages warning message to maintenance person
5、Transmission module using a backup center and the center of the main auto-recovery，And supports concurrent multi-center functions（up to five)
6. Remote configuration( convenient control )
7. Real-time remote monitoring, make a timely response to the failure
8. Comprehensive monitoring process to run the job to ensure the basis of accident analysis