Raymarine e7 - Data Master

NMEA0183
TheNMEA0183DataInterfaceStandardwasdevelopedby
theNationalMarineElectronicsAssociationofAmerica.Itisan
internationalstandardtoenableequipmentfrommanydifferent
manufacturerstobeconnectedtogetherandshareinformation.
TheNMEA0183standardcarriessimilarinformationtoSeaTalk.
Howeverithastheimportantdifferencethatonecablewillonly
carryinformationinonedirection.ForthisreasonNMEA0183is
generallyusedtoconnectadatareceiverandatransmittertogether,
e.g.acompasssensortransmittingheadingtoaradardisplay.This
informationispassedin‘sentences’,eachofwhichhasathree
lettersentenceidentier.Itisthereforeimportantwhenchecking
compatibilitybetweenitemsthatthesamesentenceidentiersare
usedsomeexamplesofwhichare:
•VTG-carriesCourseandSpeedOverGrounddata.
•GLL-carrieslatitudeandlongitude.
•DBT-carrieswaterdepth.
•MWV-carriesrelativewindangleandwindspeeddata.
NMEAbaudrates
TheNMEA0183standardoperatesatanumberofdifferent
speeds,dependingupontheparticularrequirementorequipment
capabilities.Typicalexamplesare:
•4800baudrate.Usedforgeneralpurposecommunications,
includingFastHeadingdata.
•9600baudrate.UsedforNavtex.
•38400baudrate.UsedforAISandotherhighspeedapplications.
2.9Datamaster
Anysystemcontainingmorethanonenetworkedmultifunction
displaymusthaveadesignateddatamaster.
Thedatamasteristhedisplaywhichservesasaprimarysource
ofdataforalldisplays,italsohandlesallexternalsourcesof
information.Forexamplethedisplaysmayrequireheading
informationfromtheautopilotandGPSsystems,usuallyreceived
throughaSeaT alk
ng
orNMEAconnection.Thedatamasteristhe
displaytowhichtheSeaT alk,NMEAandanyotherdataconnections
aremade,itthenbridgesthedatatotheSeaTalk
hs
networkand
anycompatiblerepeatdisplays.Informationsharedbythedata
masterincludes:
•Cartography
•Routesandwaypoints
•Radar
•Sonar
•Datareceivedfromtheautopilot,instruments,theengineand
otherexternalsources.
Yoursystemmaybewiredforredundancywithdataconnections
madetorepeatdisplays.Howevertheseconnectionswillonly
becomeactiveintheeventofafaultand/orreassignmentofthe
datamaster.
30e7/e7D—Installationinstructions