摘要
随着科学技术不断进步和社会飞速发展，热水器成为人民日常生活息息相关
的电器产品；。设计方法也开始多种多样，从而使全自动热水机显得更加智能化
。可编程控制器(PLC)以微处理器为核心，普遍采用依据继电接触器控制系统电
气原理图编制的梯形图语言进行程序设计，编程容易，功能扩展方便，修改灵活
而且结构简单，抗干扰能力强。
S7-200 系列可编程控制器指令丰富，可以接各种输出、输入扩充设备，有丰
富的特殊扩设备，其中的模拟输入设备和通信设备更是符合全自动洗衣机控制系
统的要求与特点。
本设计选择 S7-200 为核心部件，着重进行硬件接口设计，利用梯形图和指令
表进行编程，实现了水的加热控制系统的自动化。在整个设计程序以及程序结束
的处理操作过程中，更快捷。总之，整体梯形图的设计简练，有很强的可读性及
操作性。
关键字：PLC、继电接触器、可编程控制器、自动化
Model
Along with the constant progress of science and technology and the social rapid
development, the water heater become People's Daily life is closely linked
Electrical products; . Design method are also beginning to varied, so that the automatic
hot water machine appear more intelligent. Programmable controller (PLC) in the
microprocessor as the core, the widely used electrical principle diagram based on relay
contactor control system establishment of ladder diagram programming language,
programming easy, convenient function extension and modification flexible and simple
structure, strong anti-jamming capability.
S7-200 series programmable controller instruction is rich, can meet various output
and input expansion equipment, has a lot of special equipment, and the analog input
equipment and communication equipment is in accordance with the requirements and
features of fully automatic washing machine control system.
This design choose S7-200 as the core part, emphatically carries on the hardware
interface design and programming using ladder diagram and instruction list, automate
the water heating control system. Throughout the design process, in the process of the
processing operations by the end of the program and more quickly. In a word, the whole
ladder diagram design concise, has the very strong readability and operability.
Key words: PLC, relay contactor, PLC, automation
