说明：  此文档介绍了雷电对电路设计的影响，介绍了485总线在设计过程中如何进行防雷击浪涌的影响，对设计露在外面同时有需要用到485总线的电路有一定的指导意义。
(This document describes the effects of lightning on the circuit design, describes how to affect 485 lightning surges in the design process, while sticking to the design need to use circuit 485 has a certain significance.)