前言 ............................................................................................................................................. 01 RS-485与 RS-422性能指标及其标准......................................................................................... 02 RS-485与 RS-422器件及材料说明............................................................................................. 13 RS-485与 RS-422设计原理 ......................................................................................................... 13.1 基本原理 ..................................................................................................................... 13.1.1RS-485与RS -232 电路的区别与优势................................................................... 13.1.2长短连接的判断标准、物理表现与应对措施..................................................... 33.1.3 RS-485与RS-422典型应用电路与选择方法..................................................... 43.1.4 485总线上处理竞争的方法 ............................................................................... 73.2 可靠性的设计............................................................................................................. 83.2.1 网络配置 ............................................................................................................. 83.2.2 总线匹配 ............................................................................................................. 83.2.3 引出线 ............................................................................................................... 10 3.2.4 失效保护 ........................................................................................................... 10 3.2.5 地线与接地 ....................................................................................................... 11 3.2.5.1 共模干扰问题 ................................................................................... 11 3.2.5.2 ...
