目 录
第一章 恒压供水原理及工艺 ...........................................................................5
1.1 工艺要求 ......................................................................................................5
1.2 系统的组成和基本工作原理 ......................................................................5
第二章 PLC 概述 ...............................................................................................6
2.1 PLC 的组成 ................................................................................................6
2.1.1 PLC 的输入 .........................................................................................6
2.1.2 PLC 的输出 ......................................................................................6
2.1.3 PLC 的定义 ......................................................................................6
2.1.4 PLC 的特点 ......................................................................................7
2.1.5 PLC 的性能指标 ..............................................................................7
2.1.6 PLC 的分类 ......................................................................................7
2.2 PLC 工作原理 ..........................................................................................8
2.2.1 循环扫描 ..........................................................................................8
2.2.2 I/O 响应时间 ....................................................................................8
2.2.3 PLC 中的存储器 ..............................................................................8
2.3 PLC 的编程语言 ......................................................................................9
2.3.1 PLC 的编程结构功能图 ..................................................................9
2.3.2 梯形图编程语言 ..............................................................................9
2.4 PLC 的分类 .................................................................................................10
2.4.1 按 I/O 点数容量分类 .....................................................................10
2.4.2 按结构形式分 ................................................................................11
2.5 PLC 与继电器控制系统的区别 ..............................................................11
2.6 PLC 控制系统的结构 ..............................................................................12
2.6.1 单机控制系统 ..................................................................................12
2.6.2 集中控制系统 ................................................................................12
2.6.3 分散控制系统 ................................................................................12
2.7 PLC 网络及特点 ......................................................................................13
2.7.1 网络概述 ........................................................................................13
