The Design And Realization Of Coal Mine Electronic Weighing System Based On PSTN

Now, with the enhance of government management, Involved department prescribes that all coal production of year output is over 3000000 ton must use belt conveyor, it causes electronic belt weighing as a indispensable part in measure and management. The issue was aimed at the expansion project in Shanxi Wanli Co.Ltd proportioning "ICS electronic belt weighing measure and management system", the paper obtains the help and fund of the National new instruments projects (2005ED630022) in 2005.This paper has three important parts. Firstly, it mainly introduces some blast theory and Explosion-proof principle from security performance, describes the characteristics of Explosion-proof technology and explains the basic concept and important parameter detailedly. Also makes some explaination for Explosion-proof weighing indicator, blast sign and safety parameter. Secondly, it introduces how to apply the Explosion-proof technology in electronic belt weighing for coal mine from the common basic configuration. Thirdly, it compares several porpular remote data transmission systems on the point of basic principle and makes certain the project of remote data transmission system based on PSTN. The overall design includes five parts:The first part introduces the structure, working principle, constitutes and types of proportioning belt weighing system, emphasizes the application of Explosion-proof technology in electronic belt weighing for coal mine.The second part introduces hardware design principle of each unit in the system, mainly includes the monitoring and control system, Explosion-proof and Intrinsic Safety Power Supply, communication manager, digital analogue safe barrier, line arrester and PC. Monitoring and control system is the key of the system including using skill of AD7715 , collection and disposal of the speed signal, Anti-Explosion power supply , digital interface and so on.The third part introduces the design and realization of coal mine electronic weighing system based on PSTN. Compared with some remote transmission system, we establish the communicate model for remote data transmission system based on PSTN. Secondly it mainly introduces the principle, working modes, hardware criterion for modem and some AT instructions .Then discusses the hardware circuit between modem and microchip.At last,the paper discusses realization soft of system in detail.The fourth part discusses electronic belt weighing management software for coal mine. First of all, it mainly introduces management software total function. Then it introduces how to design communication module .At last, it introduces main interface diagram for system.The last part mainly introduces some ways of testing performance and concludes the result that meets GB/T 7721-1995, meanwhile, analyses the deficiency and error about system and puts forward some measures.