Simrad EK15 - Standard NMEA 0183 Communication Parameters; NMEA Sentence Structure

Telegramformats
otherstoreceivedatasimultaneously("listeners")onthesameline.Therefore,youmust
ensurethatallproductsreceivingdataonacommunicationlineissetuptoreceivethe
sametelegram(s)thatthetransmittingproductprovides.
StandardNMEA0183communicationparameters
ThecommunicationparametersdenedforNMEA0183are:
•Baudrate:4800bitspersecond
•Databits:8
•Parity:None
•Stopbits:One
Someinstrumentswillalsoofferotherparametersand/orchoices.
NMEAsentencestructure
Thefollowingprovidesasummaryexplanationoftheapprovedparametricsentence
structure.
$aaccc,c—c*hh<CR><LF>
1“$”:Startofsentence(Hex:24).
2aaccc:Addresseld.Thersttwocharacters(aa)identiestheTalkerID,whilethe
lastthreecharactersaretheSentenceformattermnemoniccodeidentifyingthedata
typeandthestringformatofthesuccessiveelds.
3“,”:Fielddelimiter(Hex:2C).Thischaracterstartseacheldexcepttheaddress
andchecksumelds.Ifitisfollowedbyanulleld,itisallthatremainstoindicate
nodataintheeld.
4c—c:Datasentenceblock.Thisisaseriesofdataeldscontainingallthedata
tobetransmitted.ThedataeldsentenceisxedandidentiedbytheSentence
formatterintheaddresseld.Dataeldsmaybeofvariablelengths,andtheyare
precededbytheFielddelimiter.
5“*”:Checksumdelimiter(Hex:2A).Thisdelimiterfollowsthelasteldofthe
sentence,andindicatesthatthefollowingtwoalphanumericalcharacterscontain
thechecksum.
6hh:Checksum
7<CR><LF>:Terminatessentence
Proprietarytelegrams
InsomeproprietarytelegramsreceivedfromotherKongsbergMaritimeequipment,the$
characterisreplacedbythe@character.Thechecksumeldmaythennotbeinuse.
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