ABSTRACT
Air quality in the demand for continuous improvement, urban environmental quality as an important component of the atmospheric environment have a direct impact on the quality to life in this city in the crowd of the living environment and health status, it is necessary to establish such a large cities Consistent with national norms in atmospheric monitoring system.
Based on the atmospheric environment monitoring standards, design a more advanced environmental monitoring control system, and from the hardware and software to achieve. The control system consists of a Taiwanese PC as a host machine, multiple MCS-51 series SCM supplemented by appropriate external circuit and a memory unit from the machine components. In the distribution system, Lord, from the machine can be parallel efforts to enhance the reliability of the system.At the same time, the monitoring system used by the sensor and the principle of functional done a detailed account of the external sensor circuit and principle to do an in-depth description. A detailed description of ADC0809 and AD574A the structure and performance of the system and choose the latter. Finally, on the AD574A and 8051 microcontroller interface circuit design and software design.
PC-general are equipped with RS232 serial interface, but its short-distance data transmission, slow, weak anti-interference capability, and Serial RS485 interfaces, long distance data transmission, anti-jamming ability. Therefore, this system uses RS485 interfaces. To achieve the upper and lower crew communications, the need for RS232 and RS485 signal conversion, which will help the RS232 and RS485 serial communication conversion circuit.
This paper also presented data acquisition system and various communication module circuit the process flow chart, after simulation run, the monitoring system has such advantages: a simple circuit structure; highly intelligent and it can be environmental factors in the atmosphere accurate Acquisition; entire communication system strong anti-interference capability.