【摘要】 介绍了基于调制解调器的电压监测系统的上位机设计与实现方法以及系统软件结构框图 使用AT命令对调制解调器进行编程 ,用微软的ActiveX控件MSComm实现了串行通信 为了确保可靠的通信 ,构造了系统的Petri网通信模型 ,分析的结果表明 ,本文建立的通信模型不会发生死锁现象 还根据实际公共电话网的通信情况 ,介绍了一种如何从受干扰的数据中提取正确数据的方法 ,此方法可大大提高通信效率 最后介绍了软件控制Access数据库进行报表打印的方法 ,这种方法使得打印的报表更加美观和专业化更多还原

【Abstract】 The software design of voltage monitor system based on modem is studied in the paper. The system software structure is elaborated. AT commands for programming modem and MSComm control are used to realize serial communication. Petri net model is adopted to analyse the system communication protocol. The results show that the communication model based on Petri net will not be dead locked forever. According to the communication environment of the pubic telephone net, a special method is introduced to take out the correct data from disturbed data and it greatly enhances the communication efficiency.Finally in order to make the report table more beautiful and more special, a software design method to control Access is discussed.更多还原