3BHE009017R0101 ABB

PLC has been widely used in the tap water industry due to its strong functions,brief program design,easy maintenance and other advantages,especially high reliability and strong ability to adapt to harsh industrial environments.However,due to the harsh environmental conditions,high humidity,and various industrial electromagnetic and radiation interference,which will affect the normal operation of the system,attention must be paid to the anti-interference design of the project.

The interference sources of PLC in the application of water plants mainly include the interference introduced by the power supply system,the interference introduced by the grounding system and the interference introduced by the input and output circuits.If the interference problem of PLC is not solved well,the system will not be able to operate reliably,which will affect the normal water supply.Therefore,it is necessary to discuss the interference problem in PLC application system.This paper mainly discusses three anti-interference technologies of PLC.

PLC由于具有功能强、程序设计简介，维护方便等优点，特别是高可靠性、较强的适应恶劣工业环境的能力，已被广泛应用于自来水行业。但由于现场环境条件恶劣、湿度高、以及各种工业电磁、辐射干扰等，会影响系统的正常工作,因此必须重视工程的抗干扰设计。

水厂应用中的PLC所受的干扰源主要有电源系统引入的干扰、接地系统引入的干扰和输入输出电路引入的干扰三类。如果PLC的干扰问题解决得不好，系统将无法可靠运行，将会影响到正常供水。因此，有必要对PLC应用系统中的干扰问题进行探讨。主要本文分别讨论PLC的三种抗干扰技术。