发布时间：2015-01-21 来源：人大经济论坛

自动化专业论文 目 录 第1章 绪论 1 第2章基于PLC技术的自动售货机的方案论证 2 2.1 自动售货机简介 2 2.2 自动售货机控制方案选择 3 2.2.1 基于单片机的自动售货机控制系统 3 2.2.2 本设计方案选择 4 2.3 本系统组成 ...4 第3章硬件设计 ...6 3.1 PLC控制的特点 6 3.1.1 PLC的产生 6 3.1.2 PLC的工作原理 6 3.1.3 PLC应用的特点 6 3.1.4 PLC的内部组成 7 3.2 系统的输入/输出信号 7 3.3 PLC选型 9 3.4 I/O地址分配 9 3.5 PLC外部接线设计 10 3.6 硬件电路设计 10 3.6.1 硬币的识别原理 10 3.6.2 加热控制电路的设计 11 3.6.3 制冷装置的设计 11 3.6.4 咖啡、果珍出口控制 12 3.6.5 出杯、制动控制 13 第4章软件设计 14 4.1 上位机监控管理程序 14 4.2 主工作站通信程序 16 4.2.1 通信协议 16 4.2.2 串行通信程序设计 16 4.3 PLC控制程序 20 4.3.1 识币检测、出杯、制动梯形图的设计 20 4.3.2 咖啡、果珍出口控制梯形图的设计 21 4.3.3 加热、制冷梯形图的设计 22 4.3.4 PLC通信程序 22 第5章结论 23 参考文献 24 致谢 26 摘 要 本论文设计的是由微机-PLC构成的自动售货机监控系统，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，对由微机-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。 在设计中选择PC机作为主工作站的上位机，下位机采用PLC作控制器，每个PLC控制器控制一个售货机子系统，三台PLC控制器分别为从工作站1，从工作站2，从工作站3，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。文中制作了上位机用户管理界面，应用VB6.0软件对上位机用户管理界面的程序以及主工作站的通信程序进行编写并调试；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。 本论文的重点放在PLC各硬件部分的设计和介绍、PLC梯形图的编写及诸工作站程序的编写上。在整体设计过程中按照“提出问题，分析问题，解决问题”的主导思想，对整个系统的设计工作做出了细致的阐述。 关键词：可编程控制器(PLC)；自动售货机；梯形图；VB Abstract The present paper design was by the microcomputer - PLC constitution automat supervisory system, this article elaborated automat and the development, as well as it in the domestic and foreign development present situation, has carried on the proof to automat plan, introduced PLC composed, the characteristic as well as the principle of work basically, to carried on a more careful elaboration by the microcomputer - PLC constitution vending machine system overall design process. Chooses PC machine in the design to take the host workstation on position machine, the lower position machine uses PLC to make the controller, each PLC controller controls a automat subsystem, three PLC controllers respectively be from the workstation 1, from the workstation 2, from the workstation 3, in the article exhaustively introduced the automat various hardware composition, and has completed the PLC exterior wiring diagram. In the article has manufactured on the position machine user management contact surface, applies the VB6.0 software carries on to on position machine user management contact surface procedure as well as the host workstation signal procedure compiles and debugs; When PLC trapezoidal chart compilation, in the article uses is Siemens PLC trapezoidal chart special-purpose translation software STEP7 carries on the compilation. The present paper key point places the PLC various hardware part the design and the introduction, the PLC trapezoidal chart compilation and in the various workstation procedure compilation. Defers to in the overall design process “asks the question, the analysis question, solves the problem” the guiding ideology, has made the careful elaboration to the overall system design work. Key words：PLC; Automat; Ladder logic diagram; VB