标准rs422接口定义9针 rs422接口定义

inkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif; WHITE-SPACE: normal; WORD-SPACING: 0px; TEXT-TRANSFORM: none; FONT-WEIGHT: 400; COLOR: rgb(38,38,38); FONT-STYLE: normal; MARGIN: 0px 0px 20px; ORPHANS: 2; WIDOWS: 2; LETTER-SPACING: normal; LINE-HEIGHT: 1.8; BACKGROUND-COLOR: rgb(255,255,255); TEXT-INDENT: 2em; font-variant-ligatures: normal; font-variant-caps: normal; -webkit-text-stroke-width: 0px; text-decoration-style: initial; text-decoration-color: initial; overflow-wrap: break-word'>这三种通讯端口都是串口，在以下几个方面有区别：
inkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif; WHITE-SPACE: normal; WORD-SPACING: 0px; TEXT-TRANSFORM: none; FONT-WEIGHT: 400; COLOR: rgb(38,38,38); FONT-STYLE: normal; MARGIN: 0px 0px 20px; ORPHANS: 2; WIDOWS: 2; LETTER-SPACING: normal; LINE-HEIGHT: 1.8; BACKGROUND-COLOR: rgb(255,255,255); TEXT-INDENT: 2em; font-variant-ligatures: normal; font-variant-caps: normal; -webkit-text-stroke-width: 0px; text-decoration-style: initial; text-decoration-color: initial; overflow-wrap: break-word'>1、通讯距离
inkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif; WHITE-SPACE: normal; WORD-SPACING: 0px; TEXT-TRANSFORM: none; FONT-WEIGHT: 400; COLOR: rgb(38,38,38); FONT-STYLE: normal; MARGIN: 0px 0px 20px; ORPHANS: 2; WIDOWS: 2; LETTER-SPACING: normal; LINE-HEIGHT: 1.8; BACKGROUND-COLOR: rgb(255,255,255); TEXT-INDENT: 2em; font-variant-ligatures: normal; font-variant-caps: normal; -webkit-text-stroke-width: 0px; text-decoration-style: initial; text-decoration-color: initial; overflow-wrap: break-word'>RS232口最大通讯距离是15米，而RS422/485最大通讯距离是1200米。
inkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif; WHITE-SPACE: normal; WORD-SPACING: 0px; TEXT-TRANSFORM: none; FONT-WEIGHT: 400; COLOR: rgb(38,38,38); FONT-STYLE: normal; MARGIN: 0px 0px 20px; ORPHANS: 2; WIDOWS: 2; LETTER-SPACING: normal; LINE-HEIGHT: 1.8; BACKGROUND-COLOR: rgb(255,255,255); TEXT-INDENT: 2em; font-variant-ligatures: normal; font-variant-caps: normal; -webkit-text-stroke-width: 0px; text-decoration-style: initial; text-decoration-color: initial; overflow-wrap: break-word'>2、所连接设备个数
inkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif; WHITE-SPACE: normal; WORD-SPACING: 0px; TEXT-TRANSFORM: none; FONT-WEIGHT: 400; COLOR: rgb(38,38,38); FONT-STYLE: normal; MARGIN: 0px 0px 20px; ORPHANS: 2; WIDOWS: 2; LETTER-SPACING: normal; LINE-HEIGHT: 1.8; BACKGROUND-COLOR: rgb(255,255,255); TEXT-INDENT: 2em; font-variant-ligatures: normal; font-variant-caps: normal; -webkit-text-stroke-width: 0px; text-decoration-style: initial; text-decoration-color: initial; overflow-wrap: break-word'>RS232只能连接一个设备，而RS485可以连接多个设备。
inkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif; WHITE-SPACE: normal; WORD-SPACING: 0px; TEXT-TRANSFORM: none; FONT-WEIGHT: 400; COLOR: rgb(38,38,38); FONT-STYLE: normal; MARGIN: 0px 0px 20px; ORPHANS: 2; WIDOWS: 2; LETTER-SPACING: normal; LINE-HEIGHT: 1.8; BACKGROUND-COLOR: rgb(255,255,255); TEXT-INDENT: 2em; font-variant-ligatures: normal; font-variant-caps: normal; -webkit-text-stroke-width: 0px; text-decoration-style: initial; text-decoration-color: initial; overflow-wrap: break-word'>3、端口的定义