RS485是一个物理接口，简单的说是硬件。

MODBUSSHIYIZHONGGUOJIBIAOZHUNDETONGXUNXIEYI，YONGYUBUTONGCHANGSHANGZHIJIANDESHEBEIJIAOHUANSHUJU(YIBANSHIGONGYEYONGTU)；SUOWEIXIEYI，YEKEYILIJIEWEISHANGMIANYOURENSHUODE“YUYAN”BA，JIANDANDESHUOSHIRUANJIAN。

YIBANQINGKUANGXIA，LIANGTAISHEBEITONGGUOMODBUSXIEYICHUANSHUSHUJU：ZUIZAOSHIYONGRS232CZUOWEIYINGJIANJIEKOU，(YEJIUSHIPUTONGDIANNAOSHANGDECHUANXINGTONGXUNKOU(CHUANKOU))YEYOUYONGRS422DE，YEYOUCHANGYONGDERS485，ZHEIZHONGJIEKOUCHUANSHUJULIYUAN，ZAIYIBANGONGYEXIANCHANGYONGDEBIJIAODUO。

MODBUSXIEYIYOUFENMODBUS RTU，MODBUS ASCIIHEHOULAIFAZHANDEMODBUS TCPSANZHONGMOSHI：

QIZHONGQIANLIANGZHONG(MODBUS RTU，MODBUS ASCII)SUOYONGDEWULIYINGJIANJIEKOUDOUSHICHUANXING(Serial)TONGXUNKOU(RS232，RS422，RS485)。

ERMODBUS TCPZESHIWEILESHUNYINGDANGJINSHIJIEFAZHANCHAOLIU，SHENMEDOUKEYIYONGEthernetWANGHUOInternetLAILIANJIE，CHUANSONGSHUJU。SUOYIYOUMODBUS TCPMOSHI，GAIMOSHIDEYINGJIANJIEKOUJIUSHIYITAIWANG(Ethernet)KOULE，YEJIUSHIWOMENDIANNAOSHANGYIBANYONGDEWANGLUOKOULE。

WOMENBAGONGYEWANGLUOGUIJIEWEISANLEI：RS485WANGLUO、HARTWANGLUOHEXIANCHANGZONGXIANWANGLUO。

HARTWANGLUO：HARTSHIYOUXIANZAIDEAIMOSHENGTICHUYIGEGUODUXINGZONGXIANBIAOZHUN，TAZHUYAOSHIZAI4～20HAOANDIANLIUXINHAOSHANGMIANDIEJIASHUZIXINHAO，WULICENGCAIYONGBELL202PINYIJIANKONGJISHU，YISHIXIANBUFENZHINENGYIBIAODEGONGNENG，DANCIXIEYIBUSHIYIGEZHENZHENGYIYISHANGKAIFANGDEBIAOZHUN，YAOJIARUTADEJIJINHUICAINENGNADAOXIEYI，JIARUJIJINHUIYAOYIBUFENDEFEIYONG。JISHUZHUYAOBEIGUOWAIJIJIADAGONGSILONGDUAN，JINLIANGNIANGUONEIYEYOUGONGSIZAIZUO，DANHAIMEIYOUDADAOGUOWAIGONGSIDESHUIPING。XIANZAIYOUHENDAYIBUFENDEZHINENGYIBIAODOUDAIYOUHARTYUANKA，DOUJUBEIHARTTONGXUNGONGNENG。DANCONGGUONEILAIKANHAIMEIYOUZHENZHENGLIYONGQIZHEIBUFENGONGNENG，ZUIDUOZHISHILIYONGSHOUCAOQIDUIQIJINXINGCANSHUSHEDING，MEIYOUFAHUICHUHARTZHINENGYIBIAOYINGYOUDEGONGNENG，MEIYOULIANWANGJINXINGSHEBEIJIANKONG。CONGZHANGYUANLAIKANYOUYUHARTTONGXINSULVDIZUWANGKUNNANDENGYUANYIN，HARTYIBIAODECAIGOULIANGHUICHENGXIAHUAQUSHI，DANYOUYUHARTYIBIAOYIJINGYOUSHIDUONIANDELISHIXIANZAIZAIZHUANGSHULIANGFEICHANGDEDA，DUIYUYIXIEXITONGJICHENGSHANGLAISHUOHAIYOUHENDADEKELIYONGKONGJIAN。

XIANCHANGZONGXIANWANGLUO：XIANCHANGZONGXIANJISHUSHIDANGJINZIDONGHUALINGYUJISHUFAZHANREDIANZHIYI，BEIYUWEIZIDONGHUALINGYUDEJISUANJIJUYUWANG，TADECHUXIANBIAOZHIZHEZIDONGHUAKONGZHIJISHUYOUYIGEXINSHIDAIDEKAISHI。XIANCHANGZONGXIANSHILIANJIESHEZHIZAIKONGZHIXIANCHANGDEYIBIAOYUSHEZHIZAIKONGZHISHINEIDEKONGZHISHEBEIDESHUZIHUA、CHUANXING、DUOZHANTONGXINDEWANGLUO。QIGUANJIANBIAOZHISHINENGZHICHISHUANGXIANG、DUOJIEDIAN、ZONGXIANSHIDEQUANSHUZITONGXIN。XIANCHANGZONGXIANJISHUJINNIANLAICHENGWEIGUOJISHANGZIDONGHUAHEYIQIYIBIAOFAZHANDEREDIAN，TADECHUXIANSHICHUANTONGDEKONGZHIXITONGJIEGOUCHANSHENGLEGEMINGXINGDEBIANHUA，SHIZIKONGXITONGCHAOZHEZHINENGHUA、SHUZIHUA、XINXIHUA、WANGLUOHUA、FENSANHUADEFANGXIANGMAIJIN，XINGCHENGXINXINGDEWANGLUOJICHENGSHIQUANFENBUSHIKONGZHIXITONG---XIANCHANGZONGXIANKONGZHIXITONGFCS(Fieldbus Control System)。DANSHIXIANZAIDEXIANCHANGZONGXIANDEGEZHONGBIAOZHUNBINGXINGCUNZAIBINGQIEDOUYOUZIJIDESHENGCUNLINGYU，HAIMEIYOUXINGCHENGZHENZHENGTONGYIDEBIAOZHUN，GUANJIANSHIKANBUDAOSHENMESHIHOUNENGXINGCHENGTONGYIDEBIAOZHUN，JISHUYEBUGOUCHENGSHU。LINGWAIXIANCHANGZONGXIANDEYIBIAOZHONGLEIHAIBIJIAOSHAOKEGONGXUANZEDEYUDIXIAO，JIAGEYEPIANGAO，CONGZUIZHONGYONGHUDEJIAODUKANDADUOHAICHUYUGUANWANGZHUANGTAI，DOUXIANGDENGDAOJISHUCHENGSHUZHIHOUZAIKAOLV，XIANZAISHISHIDESHAO。

RS485WANGLUO：RS485/MODBUSSHIXIANZAILIUXINGDEYIZHONGBUWANGFANGSHI，QITEDIANSHISHISHIJIANDANFANGBIAN，ERQIEXIANZAIZHICHIRS485DEYIBIAOYOUTEDUO，TEBIESHIZAIYOUPINXINGYERS485/MODBUSJIANZHISHIYITONGTIANXIA，XIANZAIDEYIBIAOSHANGYEFENFENZHUANERZHICHIRS485/MODBUS，YUANYINHENJIANDAN，XIANGYUANLAIDEHARTYIBIAOXIANGMAIYIGEZHUANHUANKOUFEICHANGKUNNANERQIEJIAGEANGGUI，RS485DEZHUANHUANJIEKOUJIUBIANYIDEDUOERQIEZHONGLEIFANDUO。ZHISHAOZAIDIDUANSHICHANGRS485/MODBUSHAIJIANGSHIZUIZHUYAODEZUWANGFANGSHI，JINLIANGSANNIANNEIBUHUIGAIBIAN。