摘 要 本论文是基于西门子 S7-200 系列 PLC 结构的自动轧钢机系统，本文阐述了自动轧钢机的来源与进展，以及它在国内为进展的现状，对自动轧钢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 构成的自动轧钢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轧钢机的各硬件组成，并完成了 PLC 外部接线图。在 PLC梯形图的编写时，文中采纳的是西门子 PLC 梯形图专业编译软件 STEP7 来进行编写。介绍了自动轧钢机的基本原理以及工作流程。具体说明了可编程序控制器在自动轧钢机中的作用。程序涉及到了自动轧钢机工作的绝大部分过程。利用 PLC 控制的自动轧钢机提高了系统的稳定性，保证自动轧钢机能够长期稳定运行。关键词：可编程控制器；自动轧钢机；梯形图；变频器；控制系统ABSTRACTThis paper is based on the design of Siemens s7-200 PLC structure of the vending machine system, this paper expounds the vending machine, and its source and development for the present situation of the development of the domestic of vending machines, discussed the plan, this paper introduces the basic composition, characteristics of PLC based on and working principle, Siemens s7-200 PLC vending machine system composed of overall design process for more detailed discussion.This paper introduced in detail the vending machines, hardware composition, and completed PLC external hookup. Write in PLC ladder diagram, the paper USES is when Siemens PLC ladder-diagram professional compiled STEP7 to write software. Introduces the basic principle of vending machine and the working process. Specifying the programmable controller in the vending machine in the role. Program involves a vending machine work most of the process. Use of PLC controlled vending machines, improve the stability of the system, ensure the vending machine can have a long-term and stable operation.Key words: Programmable Controller;Vending Mac...
