Fixed-line Sms Technology-based Remote Data Acquisition System

PSTN (Public Switch Telephone Net) short message, which is recently introduced by China Telecom, is a non-voice value-added service. The spread of this service makes PSTN break through the application field of traditional audio communication tool. The remote data acquisition system based on PSTN short message totally utilizes the existing telephone network and needs no more network construction. Some advantages of this system, such as widespread coverage, low operating and maintaining expenses, make it suitable for data acquisition occasion that has small data amount and low real-time requirement. This system can be a low investment and instant effect remote data acquisition solution.This paper makes use of this technology to realize the reading meter system of remote digital ammeter, which proves the feasibility of PSTN short message as the data transmission platform of remote data acquisition system. Firstly, the whole designing scheme is presented, the function of hardware and software is explained on the whole. Afterwards, according to the practical requirements, correlated communication protocols are deeply analyzed. On this basis, the function and design of every hardware circuit unit are proposed in detail. Then the overall software structure of this system is discussed thoroughly, the corresponding design scheme is brought forward, and the subprograms' designs of several main tasks are provided. Finally, some situations of systematical debugging are explained and the experiment conclusion as well as the way to perfect the system is given.