Researching On Data Acquisition And Data Processing For Web Based Discrete Manufacturing Oriented EMS

Nowadays, the consumption and the price of the energy rise unceasingly. And the market competition becomes more intense because of the market globalization. So the discrete manufacturing enterprises request to reduce production cost and management cost more eagerly than before. However, the discrete manufacturing enterprises in our nation have some problems of huge energy consumption and low produce efficiency, because of low productivity, poor management and outdated equipments. After entering the WTO, the issues have been more visible.An energy management system developed for discrete manufacturing industry is designed. The energy consumption data are very important in the system. Equipment monitoring and failure alarm are provided based on the data. The data can also be used in data mining moduel in the upper layer. So, the acquisition of the energy consumption data is very important in the entire energy management system.First of all, the present situation of the energy consumption of the discrete manufacturing enterprises is analyzed in this paper. The entire system is designed on the base of the analysis. After that, the recent development of the key technologies which have been used in the system were studied on.According to the requirement of the discrete manufacturing enterprises, an overall structure of the energy management system developed for the discrete manufacturing industry is designed. Several modules and layers are included in the system. In view of differences between discrete manufacturing enterprises, different solutions are offered to different enterprises of different sizes. The users have a good view on the energy consumption in the enterprise combined with the product information, manufacturing information and manufacturing equipment data. The information is very useful for the informationization of the enterprise.The quantity of the data that are recorded by data acquisition device over the period of real-time monitoring is very large. In order to reduce the storage space which taked by the data, a two-layer compression method is adopted in the system, composed of real-time compression layer and after-time compression layer. After analyzing some popular real-time data compression algorithms, the paper discusses three of them in the paper in details. The first one is ZOI algorithm. The second is improved sliding window algorithm and the third is compress door algorithm. The LZW compression method is used to reduce the redundancy of the database. After the data is compressed, the storage space taken by the data is reduced sharply. It is very useful in saving cost that spent on storing the energy consumption data.ASP technology is adopted to provide information service in the system. Several key technologies to realize the web service of the system are discussed, such as the technique for accessing web database, and some techniques for SQL inquiry optimization. And the newest ASP technology is discussed in details. Meanwhile, the security problems of the system and the technique about ActiveX are also discussed.In summary, the energy consumption monitoring, energy consumption data acquisition and data compression are realized in energy management system. And the manufacturing process data is included in the system, which is very useful for the upper layer analyzing. The system is very convenient for the user in monitoring the manufacturing condition of the factory, because of the data can publish to the Internet.