毕业论文-基于西门子S7-200 系列PLC的自动售货机控制系统设计_精品.doc

安徽汽车职业技术学院 毕业设计 自动售货机(饮水机)的PLC系统设计 班 级： 10-20班 专 业： 机电一体化 姓 名： 学 号： 指导教师： XXXXXXX 2013年10月 摘 要 本论文设计的是基于西门子S7-200 系列PLC构成的自动售货机控制系统，本文阐述了自动售货机的来源与发展，以及它在国内外发展的现状，对自动售货机的方案进行了论证，介绍了PLC的基本组成、特点以及工作原理，对基于西门子S7-200 系列PLC构成的自动售货机系统整体设计过程进行较为细致的论述。 文中详尽地介绍了自动售货机的各硬件组成，并完成了PLC外部接线图。在PLC梯形图的编写时，文中采用的是西门子PLC梯形图专用编译软件STEP7来进行编写。介绍了自动售货机的基本原理以及工作流程去帮助大家理解，然后把程序分为几个程序块，分别对程序块进行编程。具体说明了可编逻辑控制器在自动售货机中的作用。程序涉及到了自动售货机工作的绝大部分过程。利用PLC控制的自动售货机提高了系统的稳定性，保证自动售货机能够长期稳定运行。 关键词: PLC；梯形图；I/O点的分配；自动售货机 Abstract This graduation design is based on Siemens S7-200 series PLC constitute a vending machine control system. The design describes the vending machine source and development, and its development both at home and abroad and the present condition of the vending machine scheme are discussed. The PLC basic composition, characteristics and working principle be introduced. Detailed discussion is based on Siemens S7-200 series PLC constitute a vending machine system overall design process. It is a detailed description of the vending machine of the hardware composition and completed PLC exterior wiring diagram in this graduation design. During the writing of the PLC ladder diagram, this paper uses is Siemens PLC ladder diagram special compile software STEP7.This article introduces the basic principle of the vending machine and the working process to help you depth of understanding, and then the program is divided into several blocks, to block respectively for programming. The programmable logic controller is specified in the role of the vending machine. Program involving vending machine work most of the process. Using PLC automatic vending machine improves the systems stability, which ensures the vending machine can have a long-term stable operation. Keywords: PLC: Ladder diagram; The I/O point distribution; vending machine 目 录 摘 要 2 绪 论 4 1.1自动售货机的理论背景与实际意义 4 1.2 自动售货机设计的主要内容 4 1.3 自动售货机设计的基本思路 4 第一章 引言 6 1.1 本设计的意义 6 1.2