本案例中西门子PLC和拓普瑞DTU通讯利用的是DTU的透传模式，PLC和平台之间利用的是MODBUS-RTU协议进行通讯。S7-200通过以下两种方式支持MODBUS-RTU通信协议：

(1)：S7-200 CPUSHANGDETONGXINKOU0(port0)TONGGUOZHILINGKUZHICHIModbus RTUCONGZHANMOSHI。

(2)：S7-200 CPUSHANGDETONGXINKOU0HE1(port0HEport1)TONGGUOZHILINGKUZHICHIModbus RTUZHUZHANMOSHI。(ZHU：ZHILINGKUKEZAIXIMENZITIGONGDEXIANGGUANWANGZHANJINXINGXIAZAI)

BENANLIZHONGYONGDAODESHIDIYIZHONGFANGSHI，S7-200YONGZUOCONGZHANHEtlinkWULIANWANGPINGTAITONGXIN。

YI、XUANZECHANPIN

1.PLC：S7-200CN

2.DTU:GPRS DTU-02

ER、SHEZHIPLCTONGXUNXINXI

S7-200TONGXUNDEJULICHENGXURUXIATUSUOSHI：

TUZHONGCHENGXUCANSHUYIYIRUXIA：

·Mode：QIDONG/TINGZHIModbus，1=on;0=off

·Addr: ModbusCONGZHANDIZHI，QUZHI1-247

·Baud: BOTELV,KEXUAN1200,2400,4800,9600,19200,38400,57600,115200

·Parity: QIOUXIAOYANWEI，0=WUXIAOYAN;1=QIXIAOYAN;2=OUXIAOYAN

·Delay: YANSHI，FUJIAZIFUJIANYANSHI，QUESHENGZHIWEI0

·MaxIQ: ZUIDAIODIANSHU，YIBANKESHEZHIWEI128.

·MaxAI: ZUIDAAITONGDAOSHU，SHIPLCDEJUTIQINGKUANGERDING，YIBANKESHEZHIWEI16HUO32.

·Maxhold: ZUIDABAOCHIJICUNQIQU.

·Holdstart: BAOCHIJICUNQIQISHIQU，YI&VBxZHIDING.

·Done(WANGLUO1ZHONG)：CHUSHIHUAWANCHENGBIAOZHI，CHENGGONGCHUSHIHUAHOUZHI1.

·Error(WANGLUO1ZHONG):CHUSHIHUACUOWUDAIMA，0WEIWUCUOWU.

·Done(WANGLUO2ZHONG)：TONGXINSHIZHI1，WUModbusTONGXINSHIWEI0.

·Error(WANGLUO2ZHONG)：TONGXINCUOWUDAIMA，0WEIWUCUOWU.

Holdstart HEMaxHoldGUIDINGDESHIBAOCHIJICUNQIDEQUYU，BAOCHIJICUNQIQUYUDEFANWEIYIDINGBUNENGHECHENGXUCUNCHUQUDEFANWEICHONGTU，FOUZEWUFATONGXIN。SHANGTUZHONGZHIDINGDEBAOCHIJICUNQIQISHIQUDEZHIWEI1000，YEKEYIBUZHIDING1000.ZHIYAOSHEZHIHAOCHENGXUCUNCHUDEQUYUJIUNENGCHENGGONGTONGXIN，CHENGXUCUNCHUQUDESHEDINGRUXIATUSUOSHI：

ZAICHENGXUKUAIZHONG，CHENGXUCHUCUNQUFENPEIDEWEI1050ZHI1829.YINWEIHoldstartHEMaxholdGUIDINGDEQUYUSHI1000ZHI1040(MaxholdGUIDINGDESHIVWDEGESHU，SUOYIBIANCHENGVBXUYAOCHENGYI2)SUOYICHENGXUCHUCUNQUFENPEIWEIVB1050ZHIVB1829.

SAN、BIANXIEKONGZHICHENGXU

XIEHAOTONGXINCHENGXU，FENPEIHAOCUNCHUQUZHIHOUBIANKEYIZUOWEICONGZHANHEZHUZHANJINXINGTONGXINLE。WEILEGENGHAODEZHANSHIXIAOGUO，ZHEILIBIANXIELEYIXIEEWAIDEKONGZHICHENGXU，KONGZHICHENGXURUXIATUSUOSHI：

SI、PEIZHIDTU

DTUDEPEIZHIZHUYAOYOUPLCDETONGXUNXINXIHEtlinkPINGTAILAIJUEDING：

WU、PEIZHItlinkPINGTAIDUXIEMINGLING

ZAItlinkPINGTAIDIANJISHEBEI，ZAISHEBEILIEBIAOZHONGXUANZESHEZHILIANJIE，ZAICHUANGANQILANXUANZEPILIANGSHEZHIJIKECHUXIANRUXIAJIEMIAN：

PLCGEGEQUYUDUIYINGDEModbusDIZHIRUXIA：

·00001-09999：SHUZILIANGSHUCHU(XIANQUAN，KEDUKEXIE)

·10001-19999：SHUZILIANGSHURU(CHUDIAN，ZHIKEDU)

·30001-39999：SHURUSHUJUJICUNQI(TONGCHANGWEIMONILIANGSHURU，ZHIKEDU)

·40001-49999：SHUJUBAOCHIJICUNQI(KEDUXIE)

SHANGSHUCHENGXUZHONGXIERUJICUNQIDEZHIDUIYINGDEDIZHIWEI40001HE40002，DUIYINGPINGTAIZHONGDE03GONGNENGMA(KEDUKEXIE)PIANZHIWEI1HE2SHUJUGESHIYIJUSHIJIQINGKUANGKETIANXIEWEI16WEIWUFUHAOHUOYOUFUHAOSHU。CAIJIZHOUQIKEZIXINGSHEDING，JIANYISHEDINGWEI10.

LIU、YUNXINGPLCHEDTU

JIANGPLCHEDTULIANJIESHANGZHIHOUJIKESHIPLCYUtlinkPINGTAITONGXUNCHENGGONG，JIKEZAItlinkWULIANWANGPINGTAISHANGSHIXIANYUANJULIJIANKONG，tlinkPINGTAIDEXIANSHIJIEMIANRUXIATUSUOSHI：

PLCDEZHUANGTAIXIANSHIRUXIATUSUOSHI：

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