毕业设计（论文）报告
题 目 基于PLC的三人智力抢答器
设计
院 系 中德机电学院 专 业 机电一体化技术 班 级 1003 学生姓名 胡波 学 号 100102705 指导教师 魏甜甜
2013年 04月
无锡科技职业学院毕业设计（论文） 基于PLC的三人智力抢答器设计
基于PLC的三人智力抢答器设计
摘要：随着我国经济和文化实业的发展，在很多公开竞争场合要求有公正的竞
争裁决，诸如证券、股票交易及各种智力竞赛等，因此出现了抢答器。最初的抢答器是由优先权编码器构成的逻辑电路，其运算速度慢，线路复杂，可靠性不高，功能也比较简单，特别是当抢答路数很多时，实现起来就更加困难。因此，一种能够体现竞赛的公开、公平、公正性的知识竞赛抢答器成为一种需求。
本设计将以PLC为核心设计了系统结构图、程序指令、梯形图以及输入输出端子的分配方案，在保留了原始抢答器的基本功能的同时又增加一系列的实用功能并简化其电路结构，其将以其控制方便，灵活，只要改变输入PLC的控制程序，便可改变竞赛抢答器的抢答方案，从而使得竞赛不断完善其公平、公正性。
关键词：PLC、三人智力抢答器、LED
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无锡科技职业学院毕业设计（论文） 基于PLC的三人智力抢答器设计
Three people of intelligence Responder design based on
PLC
Abstract：With the development of our country economy and cultural
industry,public competition requires a fair adjudgement in many occasions,such as securities and ruling stock trading and various intelligence contest etc, resulting in various responder. First vies to answer first is composed of priority encoder which is constiuted by logic circuit, the speed and reliability of it is not high and the circuit is complex, but the function is simple. especially when there are many responders, it is more difficult to achieve. Therefore, a responder to reflect a kind of openness, fairness and impartiality of the knowledge competition is a kind of demand occupations. The core of this design is based on PLC ,it is composed of system structure diagram, procedures, ladder-diagram and the allocation of input and output terminals,the design not only retains the basic function of the the original responder but increases a series of practical function and simplifies the circuit structure, it will be easy and flexible to its control, as long as change the PLC control procedures, you are able to change the program of the competition responder, making the competition fair and justice.
Key words：PLC、 Three the knowledge competition responder 、LED
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无锡科技职业学院毕业设计（论文） 基于PLC的三人智力抢答器设计
目录
前言 ............................................................................................................................... 1 第一章 可编程控制器概论 ......................................................................................... 3
1.1 PLC的简介 ................................................................................................... 3 1.2 PLC的用途 ................................................................................................... 3 1.3 PLC的特点 ................................................................................................... 4 1.4 PLC发展 ....................................................................................................... 6 1.4.1 产生 ......................................................................................................... 6 1.4.2 发展趋势 ................................................................................................. 7 1. 5 PLC的分类 .................................................................................................. 7 1.5.1 按PLC的控制规模分类 ........................................................................ 7 1.5.2 按PLC的结构分类 .............................................................................. 10 1.5.3 按PLC的功能分类 .............................................................................. 11 第二章 设计方案的选择 ........................................................................................... 13
2.1 抢答器的简介 ............................................................................................. 13 2.2 三人智力抢答器控制要求 ......................................................................... 13 第三章 硬件电路设计 ............................................................................................... 14
3.1 控制特点分析 ............................................................................................. 14 3.2 PLC机型的选择步骤与原则 ..................................................................... 14 3.3 流程图 ......................................................................................................... 16 3.4 PLC与七段LED显示器连接设计 ........................................................... 17 3.4.1 LED数码管的结构及主要特性 .......................................................... 17 3.4.2 PLC与七段数码管方案选择 ............................................................... 18 3.4.3 PLC与七段数码管直接连接阻值计算 ............................................... 19 3.4.4 外部硬件接线图 ................................................................................... 19 3.5 PLC与蜂鸣器连接方法选择 ..................................................................... 21 3.5.1 蜂鸣器的介绍 ....................................................................................... 21
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无锡科技职业学院毕业设计（论文） 基于PLC的三人智力抢答器设计
3.5.2 蜂鸣器的结构原理 ............................................................................... 21 3.6 程序中所使用的西门子S7-200PLC的指令系统及指令应用 ................. 21 第四章 软件设计 ....................................................................................................... 27
4.1 IO分配 ........................................................................................................ 27 4.2 程序梯形图 ................................................................................................. 28 4.3 仿真 ............................................................................................................. 35 第五章 安装和调试 ................................................................................................... 36 第六章 总结与体会 ................................................................................................... 37 参考文献 ..................................................................................................................... 38
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