本书以工程实际应用和便于教学使用为出发点,以西门子 S7-300系列 PLC为蓝本,主要介绍可编程序控制器的工作原理、指令系统、程序结构、编程软件使用、编程规则与技巧、控制系统设计与应用技术等内容。 本书力求语言简捷、通俗易懂、实用性强、理论联系实际,通过大量工程案例介绍 PLC的设计方法。本书作为新形态教材,关键知识点处配有二维码扫描视频,且每章都有相关技能训练,以突出对实践技能和应用能力的培养。 本书适合作为电气自动化、楼宇智能化、机电一体化、机械设计与制造及其相关专业 “PLC基础与应用”课程的教学用书,也可作为电气技术人员的参考书和培训教材。

第 1章 PLC的基本知识············································· 1 1.1 PLC概述 ········································ 1 1.1.1 PLC的产生和定义 ································· 1 1.1.2 PLC的结构组成 ···································· 1 1.1.3 PLC的基本原理 ················ 3 1.1.4 PLC的编程语言 ··································· 5 1.1.5 PLC的应用和发展 ································· 7 1.2 S7-300 PLC概述 ········································ 8 1.2.1 西门子 PLC系列产品 ···························· 8 1.2.2 S7-300 PLC的硬件组成 ··· 11 1.2.3 CPU的操作模式 ································· 13 1.2.4 S7-300 PLC的工作过程 ················································· 14 1.2.5 S7-300 PLC的模块安装 ················································· 16 1.2.6 S7-300 PLC数字量信号模块的地址分配 ···································· 19 1.3习题 ························································· 20 第 2 章 STEP 7编程软件 ····································· 21 2.1 STEP 7软件安装 ······································ 21 2.1.1 安装需求 ············································ 21 2.1.2 安装 STEP 7软件包 ··· 21 2.1.3 STEP 7的授权管理 ··· 23 2.2 SIMATIC管理器 ··········· 24 2.2.1 SIMATIC管理器概述 ·· 24 2.2.2 STEP 7项目结构 ······· 25 2.2.3 SIMATIC Manager自定义选项设置 ················ 25 2.2.4 PG/PC接口设置 ········ 27 2.3 技能训练电动机起 /停控制 ·················· 28 2.3.1 用继电器-接触器控制三相交流异步电动机起 /停 · 28 2.3.2 用 PLC控制三相交流异步电动机起 /停 ······· 29 2.3.3 PLC系统的硬件组态及程序编制 ········· 31 2.3.4 方案调试 ··········· 40 2.4 PLC控制系统与其他控制系统的区别 ·· 42 2.4.1 PLC控制与继电器-接触器控制的区别 ···· 42 2.4.2 仿真 PLC与实际 PLC的区别 ··········· 43 2.4.3 PLC系统的设计步骤 ················ 44 2.4.4 PLC设计项目的下载 ················ 44 2.4.5 TIA博途 ········ 45 2.5 习题······················· 45 第 3 章 基本逻辑指令的应用 ································· 47 3.1指令基础 ·············································· 47 3.1.1 指令的基本知识 ··························· 47 3.1.2 寻址方式和累加器 ···························· 50 3.2 触点与线圈 ············ 52 3.3 基本逻辑指令 ····························· 53 3.3.1 逻辑“与”指令 ··························· 53 3.3.2 逻辑“或”指令 ············· 54 3.3.3 逻辑“异或”指令 ························· 54 3.3.4 逻辑块的操作 ······································· 55 3.3.5 信号流取反指令 ······································· 56 3.4 边沿检测指令 ·············································· 56 3.4.1 RLO的上升沿检测指令 ········································ 56 3.4.2 RLO的下降沿检测指令 ···················································· 57 3.4.3 触点信号的上升沿检测指令 ··········································· 58 3.4.4 触点信号的下降沿检测指令 ············································ 59 3.5 技能训练电动机的基本控制 ·················································· 60 3.5.1 PLC控制系统的硬件设计 ············································· 60 3.5.2 PLC控制系统的软件设计 ·········································· 61 3.5.3 方案调试 ··························································· 66 3.6习题 ········································································· 67 第 4 章 定时器的应用 ···························· ··································· 68 4.1定时器 ····························· ····················· 68 4.1.1 定时器指令 ····························· ························· 68 4.1.2 CPU的时钟存储器 ······························· ··········· 76 4.2技能训练人行横道控制 ······················· ········ 77 4.2.1 控制要求 ······························ ··············· 77 4.2.2 任务实施 ·································· ············ 78 4.2.3 方案调试 ····························· ······················· 82 4.3编程注意事项 ······························· ······················ 85 4.3.1 常闭输入触点的处理 ·········· ················· 85 4.3.2 热继电器 FR与 PLC的连接 ·············· ········ 85 4.3.3 定时器的扩展 ·········· ················· 86 4.3.4 编程规则 ·································· 87 4.4习题 ···································· 87 第 5 章 置位与复位指令的应用 ··················································· 89 5.1 置位与复位 ········································································ 89 5.1.1 置位与复位指令 ··························································· 89 5.1.2 RS触发器指令与 SR触发器指令 ·························· 90 5.2 STEP 7的用户程序结构 ············································ 92 5.2.1 STEP 7的程序块 ···················································· 92 5.2.2 STEP 7的用户程序结构和调用 ·································· 94 5.3 技能训练 1 抢答器的控制 ······································ 96 5.3.1 控制要求 ······································································ 96 5.3.2 任务分析 ·············································· 96 5.3.3 任务实施 ························