Simrad TV80 - NMEA Datagram Formats

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406388/B
TheNMEA0183InterfaceStandarddeneselectricalsignalrequirements,data
transmissionprotocolandtime,andspecicsentenceformatsfora4800baudserial
databus.Eachbusmayhaveonlyonetalkerbutmanylisteners.
NationalMarineElectronicsAssociation
FormoreinformationabouttheNationalMarineElectronicsAssociationandtheNMEA
0183standard,refertotheorganization'swebsiteat:
•http://www.nmea.org
NMEAsentencestructure
AdenessentencestructureisdenedbyNMEAtoestablishthecommunicationbetween
twounits.Mostotherdatagramformatsaredesignedusingthesame,orasimilar,structure.
Thefollowingprovidesasummaryexplanationoftheapprovedparametricsentence
structure.
$aaccc,c-c*hh<CR><LF>
1"$"
Thischaracter(Hex:24)isusedtoidentifythestartofthesentence.
2"aaccc”
Thisistheaddresseld.Thersttwocharacters(aa)identiesthetalkerID,whilethe
lastthreecharactersarethesentenceformattermnemoniccodeidentifyingthedata
typeandthestringformatofthesuccessiveelds.
3","
Thecomma(Hex:2C)isusedaselddelimiter.Thischaracterstartseacheldexcept
theaddressandchecksumelds.Ifitisfollowedbyanulleld,itisallthatremains
toindicatenodataintheeld.
4"c-c"
Thisisthedatasentenceblock.Thisisaseriesofdataeldscontainingallthedatato
betransmitted.Thedataeldsentenceisxedandidentiedbythesentenceformatter
intheaddresseld.Dataeldsmaybeofvariablelengths,andtheyareprecededby
theelddelimiter.
5"*"
Thischaracter(Hex:2A)isthechecksumdelimiter.Thisdelimiterfollowsthelast
eldofthesentence,andindicatesthatthefollowingtwoalphanumericalcharacters
containthechecksum.
SimradTV80ReferenceManual