Multiple Research And Development, Public Telephone Billing System

Along with the rapid development of state economy construction and the communications enterprise, the public telephones have already spread all over the streets and lanes gradually, facilitated the people greatly, became a social life essential part. However, because of the scattered characteristic of the public phone, bring very great trouble to management of the public phone. Some questions of public phone fee administrative system have still existed in the present, especially because communication is slow, lack the dynamic programming function, caused telecommunication operator to the telephone fees, the way of fee adjustment cannot reflect in time in the public telephone fee system, at the same time to public phone owner lack effective supervision management method, therefore brought greatly negative influence for the public telephone enterprise development. Along with the communication and micro-electronics technology development, the technology of the embedded modem and micro-controller dynamic programming technology IPA(In-Application Programming) obtains the popularization, at the same time also causes these technologies to apply to the public telephone fee system to become the reality.In view of existing problem of the public phone fee terminal at present generally based on "MCU+ EPROM + LCD", Multi-channel public telephone fee system that thesis research and develop to use embedded micro-controller, embedded FSK modem and Multi-Line liquid crystal display monitor for the main body new modular overall structure, embedded application of technology make systematic structure compactness, steady reliable. Under analyzing and researching demand of the hardware and software of the multi-channel public telephone fee system, the system overall structure, to carry on the design of the micro-controller system, the FSK modem communications system, the telephone line interface, the keyboard and the display interface, etc. On the one hand, to realize the on-line real-time update program function in multi-channel public telephone fee system using the FLASH memory dynamic programming technology of micro-controller. On the other hand researching the operation principle of embedded FSK modem, designing and applying in the telephone line interface, enhanced the system communication speed, anti-interference ability and transmitted the stability, has realized the reliable transmission oflong-distance range and great data quantity on the telephone line. The development multi-channel public telephone fee system have real-time costs and display function, communication function, standby-program, standby-fee fixed time starts the function, the program automatic upgrade function, the statistical function of charge, to prevent embezzling phone function, and anti-lightning strike function. Solves a series of problem of communication speed is slow, cannot the real-time update program, instability in the multi-channel public telephone system at present. System already has promoted application broad more than 10 provinces in domestic, and spread to the Asia, Africa.