PLC基于Multisim的水罐监控的设计与仿真+梯形图
毕业论文关键词：Multisim，8051 单片机，PLC，A/D 转换器。
Abstract With the progress of the society water is playing an increasingly important role in ourlives, living water and industrial water most of the time need water tank, and for safetyproduction various shape of these tanks are state parameters need to monitor. Therefore,the design a can meet the requirements, simple and low cost of the monitoring system isnecessary. Ni Multisim is a electronic design automation software, the use of Multisim canenable beginners to quickly integrate into the relatively good learning atmosphere, usingMultisim process through hands-on practice to consolidate the theoretical knowledge,which found that easy to use in interactive circuit teaching learning platform. This design is8051singlechip as the core, a / D converter, LCD1602 and several device is composed of amonitoring and control system, the temperature of the water tank through the A / Dconverter analog signal is converted into digital signal, into 8051 single chipmicrocomputer for processing, and then displayed on the LCD1602. This design iscontrolled by PLC tank liquid level can be tank liquid level automatic control andmonitoring, but also can realize the automatic alarm function, Multisim This softwareplatform can achieve efficient and fast simulation.
Keywords:Multisim，8051singlechip，PLC，A/D Converter
目 录
第一章 绪 论....1
1.1 课题研究背景1
第二章 水罐监控设计要求与设计方案. 2
2.1 课题任务....2
2.2 系统设计步骤：..2
图 2-1 系统设计步骤....3
2.3 总体设计方案.3
2.3.1 系统总体方案的选择...3
第三章 软件介绍. 6
3.1 Multisim 介绍.6
3.1.1 Multisim开发背景：.6
3.2 Multisim 使用.7
3.2.1 Mltisim 界面....7
3.2.2 Multisim对元器件的管理...8
3.2.3 连接线路11
3.2.4 输入并编辑电路...12
3.3 Multisim 特点..12
第四章 硬件电路设计.... 13
4.1 系统电路图...13
4.2 8051 单片机.13
4.2.1 8051 单片机概述：...13
4.2.2 8051 主要功能.14
4.2.3 8051 引脚的功能和符号14
4.2.4 单片机最小系统设计.16
4.2.5 温度采集电路...17
4.3 PLC 的基本介绍17
4.3.1 PLC 概述.17
4.3.2 编程语言类型..18
4.3.3 PLC 工作原理..19
4.3.4 PLC 功能特点...19
4.4 A/D 转换设计....20
4.4.2 A/D 转换种类...22
4.4.3 A/D 转换的主要技术参数...23
4.4.4 信号放大24
4.5 显示器电路设计....24
4.5.1 LCD1602液晶屏引脚.24
4.5.2 1602LCD的指令说明及时序....25
4.5.3 LCD 与8051 单片机接口设计..29
4.6 温度检测电路....30
第五章 程序设计.... 31
5.1 主程序31