1、 I 摘 要 恒压供水系统设计内容包含了硬件接线图的设计、可编程控制器 S7-300 的程序编 写和 WinCC 与 S7-300 的通讯等。 S7-300 程序完成了模拟量处理等功能，即把传感器输入的 4-20mA 的模拟信号转换 成 0-27648，再根据量程转换到实际工程中水位的实际量程值，系统实现了水箱水位的 高低来控制水箱进水阀的开关以及水泵开关状态的控制。系统还实现了两个水泵定时交 替运行，运行时间可以更改。 WinCC 编辑完成了系统流程图， 报警图的绘画， 变量实时曲线的记录以及报表记录 功能。在画面中可以实现电机的启动，而且当启动时电机会有闪烁效果；还可以更改系 统内部参数，
2、比如电压量程，电流量程，水位量程等。水箱水位，管道压力，泵电压， 泵电流等关键值会显示在工艺流程画面中；水位增加时，画面能直接显示水位的变动。 以上这些功能使操作人员能更加直观的观察到系统的工作状态，便于操作管理。 关键词：恒压供水；可编程控制器；WINCC；S7_300 II Abstract This design is targeted by PLC on constant pressure water supply system design, design content includes the wiring diagram of the hardware modification
3、s, S7-300 programming, WinCC and S7-300 communication. S7-300 program completed the analog processing and other functions, namely the sensor input4-20mA analog signal is converted into0-27648, then according to the range conversion to the actual project level actual range values, system realizes the
4、 water tank water level control of water tank inlet valve switch and a water pump switch state control. The system also achieved a two pump timing alternating operation, operation time can change. WinCC editing completed the system flow chart, alarm figure painting, variable real-time curve record a
5、nd report function. In the picture can achieve the motor starting, and when activated motor will have a flashing effect; can also change the system internal parameters, such as voltage range, the range of current water level range, etc The water level of the water tank, pipeline pressure, pump pump
6、voltage, current and other key values are shown in the process of the picture; water levels increase, the picture can directly display the water level change. These functions enable the operator to more intuitive to observe the working state of a system, convenient for operation and management. Keywords: constant pressure water supply; Programmable controller; WINCC; S7_300 III 目 录 1 绪论 1 1.1 课题研究的背景及意义 . 1 1.2 国内外研究现状及发展趋势 1 1.3 可编程控制器的优点 3 1.4 恒压供水系统 4 1.4.1 恒压供水系统介
