基于PLC液体搅拌机控制电气设计.doc

毕业论文 题目：基于PLC的液体搅拌机控制电器设计 基于PLC的液体搅拌机控制电气设计 摘 要 伴随着PLC、单片机等许多处理器的发展，传统控制模式的电机的数量已经越来越少了，而自动控制模式的电动机的数量则越来越多。这是因为传统的控制方式技术手段落后、生产效率低等弊端已不能适应企业生产的需要，本文主要是介绍使用西门子S7-200实现对液体搅拌系统进行的自动控制。基于PLC为控制核心构成的用于两种液体自动进料、自动搅拌和自动放料系统的控制目标、硬件组成、软件设计及系统功能，能模拟显示液体搅拌系统工作的全部过程。 系统硬件主要由S7-200可编程控制器、电磁阀、电动机以及液位传感器器等组成，编程软件采用西门子编程软件STEP7-MICRO/WIN。系统通过液位传感器将采集到的现场液位高度传送给西门子PLC，并由PLC对现场数据逻辑处理后，发出相应的控制指令，完成系统的自动控制。最后，系统使用接口与上位机相连实现PLC与计算机的通讯。系统不仅自动化程度高，灵活性强, 而且还具有在线修改功能，可以满足不同生产工艺的要求。 关键字：PLC，液体搅拌系统，液位传感器，电磁阀  DESIGN OF ELECTRICAL CONTROL LIQUID MIXER BASED ON PLC ABSTRACT With the development of PLC and single-chip and many computer processer, the number of traditional control mode of the motor has less and less, and the number of automatic control mode of the motor is more and more. Because traditional control mode disadvantages, low production efficiency, backward technology can not adapt to the needs of enterprise production, this paper mainly introduces using Siemens S7-200 implementation of liquid mixing system automatic control,Based on PLC as the control core,which is used in the form of two kinds of liquid automatic feeder, automatic feeding and automatic mixing system control target, hardware composition, software design and system function, the simulation shows that the fluid mixing system of all process. The system hardware is mainly composed of S7-200 programmable controller, electromagnetic valve,and other components of the motor and the liquid level sensor, programming software adopts Siemens STEP7 programming software -MICRO/WIN. System by the level of liquid level sensor will be collected to Siemens PLC,and after processing by PLC to field data logic, a corresponding control instruction, complete the automatic control system. Finally, system are connected to the PLC using the interface realization of PLC and computer communications. System is not only a high degree of automatic, flexibility,but also has the function of