Iskra MC320 - Page 72

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APPENDIXC:PROFIBUSPROTOCOL
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64 Measuringcentres
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MC320,MC330,MC350&MC350H‐User’sManua
l
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TheoutputtelegramisusedtoindicatetotheMC350Hwhichdatamoduleshouldbereturnedinthefollowing
inputtelegram.OutputtelegramisalsousedtowritevaluestotheMC350Houtputmoduleregisters.Header
byte0indicatesthemodulenumberindexbeingrequested.Thisnumber(1‐4)tellstheMC350Hwhichmodule
ofmeasuringdatashouldbetransferredinsidetheinputtelegramwhichfollowsnextorwithnumber5indicates
theoutputmodulebeingwritten.
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Headerbytes1and3arenotused.Headerbyte2isusedasacontrolbytetocontroloperationflowasfollows:
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B7 B6 B5 B4 B3 B2 B1 B0
WRXXXXXXDU
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Bit0whensetto1tellstheMC350Hdevicethatitshouldupdateinternalmeasuringdatawhicharecurrently
activeontheProfibusexchangetelegram.Ifthisbitissetto0,dataarenotrefreshedontheProfibusnetwork.
Bit7whenclearedindicatesthatwriteoperationtothemodule5outputregistersisbeingexecuted.Whenset
indicatesthatreadoperationofthe1‐5moduleregistersisperformed.
InDatabytessectionwhichfollowsHeaderbyte4upto124bytesofmeasuringdataforanyofthe4modules
couldbeincluded.Moduletabledefinitionisdescribedinnextsection.
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MC350Hinputtelegramisdefinedas:
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SlavetelegramtotheMaster Meaning/contents Value
Headerbyte0 telegramID
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ormodulenumberofthe
returneddatasegment
1‐5
Headerbyte1 reserved‐notusedatthistime 
Headerbyte2 reserved‐notusedatthistime 
Headerbyte3 statusbyte XXXUPXXIDX
Databytes4‐128 upto124bytesofuserdata userdatabeingexchanged
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Headerbyte0indicatesthemodulenumberindexbeingrequested.Withthisnumber(1‐5)MC350Hindicatesto
theMasterwhichmoduleofdataisbeingtransferredinsidetheSRDdatasection.
Headerbytes1and2arenotused.
Headerbyte3isusedasastatusbytewiththefollowingmeaning.
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B7 B6 B5 B4 B3 B2 B1 B0
X X X UP X X ID X
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Withbit4(UP)setto1MC350HindicatestotheMasterthatinternaldataupdateisinprogress.Value0means
thatinternaldataprocessingcompleted.
Withbit1(ID)setto1MC350signalizestotheMasterthattelegramIDinsidetheheaderbyte1iswrong(notin
therange1‐5).ThispreventserrorswhenaddressingwronginputtelegramsattheMasteroutputtelegram.
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