Lumel P30U series - MODBUS Protocol Description

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Fig.29. Method of connecting the RS-485 interface
Computer
Transducer P30
Transducer P30
Transducer P30
The PC card transmission line marking depends on the card
manufacturer.
5..2. MODBUS protocol description
 TheimplementedprotocolcomplieswithModicon’sPI-MBUS-
300RevGspecification.P30UMODBUSprotocolserialinterfacepara-
meters:
Transduceraddress1..247.
Transmission rate: 4800, 9600, 19200, 38400, 57600, 115200,
230400,256000[b/s].
Operationmode:RTUwiththeframeformat:8n2,8e1,8o1,8n1.
Maximumtimetostartresponse:200ms(theresponsetimemay
get longer up to 500ms during saving thedata to theSD/SDHC
card).
 Serialinterfaceconfigurationconsistsofsettingthetransmis-
sionrate,deviceaddressandtheinformationunitformat–protocol.
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