作为上世纪80年代早期批准的一个平衡传输标准，RS-485似乎已成为工业界永不过时的接口标准。关于它的文献有很多，但对于很少接触接口设计的系统工程师而言，如此海量的文献就有些让人吃不消了。

本文旨在讨论RS-485标准的主要内容，为初接触它的设计师提供入门指南。研究文末参考的一些附加应用笔记可进一步帮助设计师在最短的时间内完成一套可靠的数传设计。

-As the last century, the early 80 s approval of a balanced transmission standard, RS-485 seems to have become the industry standard interface never outdated. Literature about it a lot, but seldom come into contact with the system interface design engineers, such a mass of literature on some people too much of. This paper aims to discuss the RS-485 standard of the main elements for the early exposure to its designers Getting Started Guide. Study the text at the end of the reference number of add-on application notes, could further help to designers in the shortest time possible to complete a set of reliable data-transmission design.