文档介绍：摘要
在工农业生产过程中,经常需要对水位进行测量和控制。水位控制在日常生活中应用也相当广泛,比如水塔、地下水、水电站等情况下的水位控制。然而随着世界人口的不断增长,人们生活用水的增加,以往采用的继电器水塔水位自动控制系统由于频繁操作会产生机械磨损,不方便维护和更新,已经不能满足人们的实际需求,本文采用的是西门子S7-200系列小型PLC可编程控制器作为水塔水位自动控制系统核心,对水塔水位自动控制系统的功能进行性进行了需求分析。主要实现方法是通过传感器检测水塔水位的实际水位,将水位具体信息传至PLC构成的控制模块,经A/D转换后,进行数据比较,来控制抽水电机的动作,同时进行数据还原,显示水位具体信息,如果水位低于或高于某个设定值是,就会发出危险报警的信号。本文以一个水塔水位控制系统的设计过程,给出了基于PLC水塔水位控制系统的设计好实现的具体过程。
关键词: 水位控制,西门子S7-200 ,传感器
ABSTRACT
In the industrial and agricultural production process, often need to measure and control thewater level. Water level control applications in everyday life are very wide, such as water towers, groundwater, hydropower and other water level control case. But with the growing world population, it is the increase in water, relay towers used in the past, the water level automatic control system operation due to the frequent cause mechanical wear, convenient maintenance and updating can no longer meet the actual needs of the people, the paper used Siemens PLC S7-200 programmable controller as a series of small water tower water level automatic control system core, the water level of the tower the functions of automatic control system of the requirement analysis. Main achieved is through the actual water level sensor detects the water tower, specific information will be transmitted to the water level control module consisting of PLC, the A / D conversion, pare data, to control the pumping action of the motor, while data reduction, the indicated level specific information, if the water level lower or higher than a set value, we will send the hazard warning signal. In this paper, a water tank level control system design process, the water tower level control system based on PLC design a good implementation of the specific process. 
KEY WORDS: Water level control, Siemens S7-200, The sensor
目录
摘要 I
ABSTRACT I
第1章引言 1
第2章可编程器简介 2
2
PLC的发展 4
PLC的基本结构 5
中央处理单元(CPU) 5
存储器 6
输入/输出模块 7
扩展模块 8
编程器 8
PLC