The Design Of Data Acquisition And Transmission Equipment Of Pollution Emission

With the development of The Internet of Things for environmental protection, our country would construct a space integrated and comprehensive environmental monitoring system during the 12th Five-Year Plan. In this paper,an embedded equipment for real-time monitoring acquisition data and mobile data transmission was established based on the mobile network which has the largest wireless coverage area. With its base in Tianjin to serve the whole country, it would provide technical support to energy-saving and emission reduction, significant pollution source real-time monitoring system and sudden environmental pollution accident emergency system. A data acquisition and transmission equipment was designed for auto monitoring pollution emission based on ARM11 chip according to "Standard for data communication of pollution emission auto monitoring system" (HJ/T212-2005) and "The technical requirement for data acquisition and transmission equipment of pollution emission auto monitoring system" (HJ 477-2009) released by Ministry of Environmental Protection of PRC. The long-term vision of the design was the establishment of Internet of Things for environmental protection in Tianjin.The data acquisition and transmission equipment of pollution emission in this paper had following technical characteristics:1. An ARM platform was built up relying on the new Samsung S3C6410 processor. And a kind of A/D sampling module of this equipment was developed with eight analog input channels (4~20mA current input) and 12 bits resolution.2. Through serial port extended chip, the equipment had five digital input channels under RS232 (RS485) protocol, which were applied for the bidirectional data and command transmission with the monitoring instruments.3. This equipment supported two types of network transmission both wireless and wired. Siemens MC39i was adopt as the core of the Data Transmission Unit to realize the wireless data transmission by GPRS network while DM9000 network chip was used for the wired Ethernet data transmission.4. A self-designed power module was made to provide the collaborative power for the equipment both from external AC power supply and battery backup. Because the HJ 477 standard claimed that“the data acquisition and transmission equipment of pollution emission should have the ability to operate at full load at least six hours when the external power is cut off”.5. Based on customization of Windows CE embedded OS, the embedded application software was developed to implement the communication protocol (HJ/T212) and human-computer interaction.6. In this design, the SQLite database technology was introduced to preserve the pollution information data on the embedded system. This application would provide reliable and efficient data sources for the subsequent development of cloud computing platform on The Internet of Things for environmental protection.Now the pollution emission data acquisition and transmission equipment called TY-001, which was based on the above design, had small batch production, and prototype had been able to communicate with CEMS and COD instruments through analog and digital interface. The data acquisition of prototype was not only stable but also reliable. Recently, this prototype had passed the EMC test and high-low temperature test hold by the Tianjin Quality Supervision and Inspection Station. Meanwhile, the prototype had obtained the certification issued by China National Environmental Monitoring Centre on the accuracy of the equipment and the correctness of HJ212 communication protocol. The data acquisition and transmission equipment of pollution emission would enter the domestic market after passed the 60-days MTBF test.