CW12 GPS User Manual - NavSync GPS User Manual Issue: V 12 ... Connector Data/Power: 10 pin (2 x 5)...

CW12 GPS User Manual

Issue: V 12

Bulletin NS04-UMRevision 12Date 07 May 2010

CW12 Software User Manual of 68 Ver 12 Date: 05/07/10

Copyright ©2010 NavSync Ltd. All Rights Reserved Specifications subject to change without notice.

Table of Contents1. INTRODUCTION ................................................................................................................................................................42 . SPECIFICATION .............................................................................................................................................................6-8 2.1 Performance..................................................................................................................................................6 2.2 BlockDiagram...............................................................................................................................................6 2.3 CW12GPSMTIEPerformance.....................................................................................................................6 2.4 MigratingfromMotorolaM12+toNavSyncCW12........................................................................................7 2.5 Autosurvey(timingversionsonly).................................................................................................................7 2.6 T-RAIMAlgorithm(timingversionsonly)........................................................................................................73 . PHYSICAL CHARACTERISTICS ...................................................................................................................................8-9 3.1 ElectricalConnections...................................................................................................................................8 3.2 InterfaceProtocol...........................................................................................................................................94. OPERATING MODES .......................................................................................................................................................95. POWER MANAGEMENT ...................................................................................................................................................96. COMMUNICATION PROTOCOLS ..............................................................................................................................10-60 6.1 PortConfiguration........................................................................................................................................10 6.2 OutputFormat........................................................................................................................................10-48 6.2.1MotorolaBinaryFormat......................................................................................................................10 6.2.1.1OnePulsePerSecond(1PPS)Timing............................................................................................11 6.2.1.21PPSCableDelayCorrectionand1PPSOffset..............................................................................11 6.2.1.3SupportedMotorolaBinaryI/Ocommands................................................................................12-48

6.2.1.3.1SatelliteMaskAngleMessage(@@Ag)..................................................................................136.2.1.3.2SatelliteIgnoreListMessage(@@Am)...................................................................................146.2.1.3.3PositionHoldParametersMessage(@@As)..........................................................................156.2.1.3.4TimeCorrectionSelect(@@Aw).............................................................................................166.2.1.3.51PPSTimeOffsetCommand(@@Ay)....................................................................................176.2.1.3.61PPSCableDelayCorrectionCommand(@@Az).................................................................186.2.1.3.7VisibleSatelliteDataMessage(@@Bb)..................................................................................196.2.1.3.8AlmanacStatusMessage(@@Bd).........................................................................................206.2.1.3.9AlmanacDataRequest(@@Be-responseisCb)..................................................................216.2.1.3.10AlmanacDataInput(@@Cbresponseis@@Ch)................................................................226.2.1.3.11EphemerisDataOutputMessage(@@Biresponse@@Bf)................................................236.2.1.3.12EphemerisDataInput(@@Bfresponse@@Cb)..................................................................246.2.1.3.13UTCOffsetOutputMessage(@@Bo)...................................................................................256.2.1.3.14RequestUTC/IonosphericData(@@Bp)...............................................................................266.2.1.3.15ResettoDefaults(@@Cf).....................................................................................................276.2.1.3.16ReceiverID(@@Cj)..............................................................................................................286.2.1.3.17ASCIIPosition(@@Eq).........................................................................................................296.2.1.3.18CombinedPositionMessage(@@Ga)..................................................................................316.2.1.3.19CombinedTimeMessage(@@Gb).......................................................................................326.2.1.3.201PPSControlMessage(@@Gc)..........................................................................................336.2.1.3.21PositionControlMessage(@@Gd).......................................................................................346.2.1.3.22T-RAIMSelectMessage(@@Ge).........................................................................................356.2.1.3.23T-RAIMAlarmMessage(@@Gf)...........................................................................................366.2.1.3.24LeapSecondPendingMessage(@@Gj)..............................................................................376.2.1.3.25VehicleID(@@Gk)................................................................................................................386.2.1.3.26ChannelPosition/Status/Data(@@Ha).................................................................................396.2.1.3.27ShortPositionMessage(@@Hb)..........................................................................................436.2.1.3.28ChannelTimeRAIMStatusMessage(@@Hn).....................................................................456.2.1.3.2912ChannelSelf-TestMessage(@@Ia).................................................................................476.2.1.3.30SystemPower-OnFailure(@@Sz)........................................................................................48



6.2.2NMEAMessages...........................................................................................................................49-55 6.2.2.1GLL,Geographicposition,Lat/Lon..............................................................................................49 6.2.2.2GGA,GPSfixdata......................................................................................................................50 6.2.2.3GSA,GPSDOPandActivesatellites..........................................................................................50 6.2.2.4GSV,GPSSatellitesinView........................................................................................................51 6.2.2.5RMC,RecommendedMinimumdata..........................................................................................51 6.2.2.6VTG,CourseovergroundandGroundspeed.............................................................................52 6.2.2.7POLYT,TimeofDay....................................................................................................................52 6.2.2.8POLYP,PositionData..................................................................................................................53 6.2.2.9POLYU,UTMPositionData.........................................................................................................54 6.2.2.10POLYG,LocalGridPositionData..............................................................................................54 6.2.2.11POLYS,SatelliteStatus.............................................................................................................54 6.2.2.12POLYI,AdditionalInformationMessage....................................................................................55 6.2.3ProprietaryCommands..................................................................................................................56-60 6.2.3.1PRTH<Q|S|R>,DRLM:DEADRECKONINGLIMIT.....................................................................56 6.2.3.2PRTH<Q|S|R>,ILLH:INITIALIZEDLAT,LONG,HEIGHTPOSITION.........................................57 6.2.3.3PRTH<Q|S|R>,ITIM:INITIALIZETIMEANDDATE.....................................................................57 6.2.3.4PRTH<Q|S|R>,MMSV:MIN&MAXSATELLITESFORAPOSITIONSOLUTION....................58 6.2.3.5PRTH<Q|S|R>,MCNO:MINIMUMSIGNALCNO........................................................................58 6.2.3.6PRTH<Q|S|R>,DYNA: RECEIVERDYNAMICS....................................................................59 6.2.3.7PRTH<Q|S|R>,RSET: RE-SETTHERECEIVER..................................................................59 6.2.3.8PRTH<Q|S|R>,ELVM: SATELLITEELEVATIONMASK........................................................60 6.2.3.9PRTH<Q|S|R>,COMA: COMAMODE....................................................................................60 6.2.3.10PRTH<Q|S|R>,FRQD: FREQUENCYOUTPUTSELECT.....................................................607. Frequency Output ...........................................................................................................................................................618. Boot Options ...................................................................................................................................................................62 8.1.1FlashProgramming............................................................................................................................629. NMEA Configurability Details ...................................................................................................................................63-64 9.1NMEAConfigurationQuery($PRTHQ,U1OP):......................................................................................63 9.2NMEAConfigurationSet($PRTHS,U1OP):..........................................................................................64 9.3UARTConfigurationQuery($PRTHQ,U1CM):......................................................................................64 9.4UARTConfigurationSet($PRTHQ,U1CM):..........................................................................................6410 . MISCELLANEOUS....................................................................................................................................................65-67 10.1Glossary..............................................................................................................................................65 10.2ContactDetails...................................................................................................................................67 10.3InternetInformation.............................................................................................................................67

Table of Contents



1. INTRODUCTIONTheCW12GPSreceivermoduleisanintegratedtimingmodulepoweredbyNavSync’sCW25GPSreceiver.Ithasbeenspe-cificallydesignedforuseinsynchronizationandtimingapplications, TheCW12hasanon-boardprogrammableNCOoscillatorthatoutputsasynthesizedfrequencyupto10MHzthatissteeredbytheGPSreceiver. TheCW12hasaselfsurveymodeofoperationthatallowsthereceivertoenterapositionholdmodetoallowaccuratetimingtobecontinuedwithonlyonesatellitebeingtracked. TheoutputfrequencyishighlyaccurateandcanachievefullPRCMTIEperformance. ItcanalsotracksatellitesandprovideGPSsynchronizationinweaksignalareassuchasindoorapplications.Thisreducestheneedforhighantennaplacementinmanyenvironments. TheCW12receivermoduleisa40x60x10packagewith10pin(2x5)interfaceforeaseofplacement.

Key Features of the CW12 include: • 3V - 3.6V operation • 12 channel simultaneous operation • Fully calibrated to UTC at USNO • 40 x 60 x 10 form factor • 45 s typical cold start TTFF • 38 s typical warm start TTFF • 5 s typical hot start TTFF • <0.5 s reacquisition • Position hold for improved accuracy • Antenna current limit • Motorola M12 form factor

ThisdocumentprovidesinformationontheHardwareandSoftwareelementsoftheCW12.

Key information includes: • System Block Diagram • Maximum Ratings • Physical Characteristics • Signal Descriptions • Special Features

Operating ModesPower ManagementCommunication ProtocolsDescription of Frequency Output Boot Options

TheCW12receiverprovidesposition,velocity,timeandsatellitetrackingstatusinformationviaaserialport.TheCW12receiverhasatwelveparallelchanneldesigncapableoftrackingtwelvesatellitessimultaneously.ThemodulereceivestheL1GPSsignal(1575.42MHz)fromtheantennaandoperatesoffthecoarse/acquisition(C/A)codetracking.Thecodetrackingiscarrieraided.TheCW12isdesignedspecificallyforprecisetimingapplications.



CW12-TIM GPS RECEIVER SPECIFICATIONS

SPECIFICATIONS NOTE Physical Moduledimensions 60mm(D)x40mm(W)x10mm(H) Supplyvoltages 3.0-3.6V Operating/StorageTemp -40°Cto+75°C/-55°Cto+125°C Humidity 5%to95%non-condensing MaxAcceleration/Jerk 4g/1gs-1(sustainedforlessthan5seconds) 1 Datum WGS-84Default Connector Data/Power:10pin(2x5)unshroudedheader on0.050inchescenters.RF:MMCX (subminiaturesnap-on)

Sensitivity Acquisition/Tracking -173dBW/-186dBW(-143dBm/-156dBm)

Acquisition StandAlone(Outdoor) Cold:<45s Time Warm:<38s Hot:<5s Re-acquisition:<0.5s(90%confidence)

Accuracy Position:Outdoor/Indoor <5mrms/<50mrms Velocity <0.05ms Latency <200ms RawMeasurementAccuracy Pseudorange<0.3mrms,Carrierphase<5mmrms Tracking Codeandcarriercoherent

Power 1fixpersecond 0.6Wtypically

Interfaces Serial 1port,CMOSlevels

Multi-functionI/O 1PPSandFrequencyOutput

2StatusLEDs

Protocols NMEA0183orMotorolaBinary

1ppsTimingOutput 10nsrmsaccuracy,<5nsresolution

PulseWidthNMEA:100µS;MotorolaBinary:200ms 2

FrequencyOutput NMEA:10Hzto10MHz;MotorolaBinary:10MHz 2

ReceiverType 12parallelchannelx32tapsupto32pointFFT.

Channels,tapsandFFTcanbeswitchedoffto

minimizepowerorsimulatesimplerdesigns.

General Processor ARM966E-Sona0.18micronprocessatupto120MHz.

Note:

1. Timing Applications typically assume static operation.

2. Could be customized



2. Specifications continued

2.2 Block Diagram

2.3 CW12 GPS MTIE PerformanceThegraphbelowdemonstratestheMTIEperformanceoftheCW25-TIMoutputfrequencyrelativetoaCaesiumatomicclock,withtheCW12GPSoperatingwithaclearviewofthesky.

CW25GPS

ENGINE

50mACurrent

Limit

BrownoutSupervisor

3V

Power-OnReset

AntSupply

GND

1PPS

FREQ OUT

L1 IN

Battery

NMEA / MOTOROLA BINARY

Figure 1 Block Diagram

Figure 2 CW12’s 10 MHz Output MTIE Performance (PRC mask)



2. Specifications continued

2.4 Migrating from Motorola M12+ to NavSync CW12TheCW12wasdesignedtomeettheformandfunctionalityoftheM12ascloselyaspossibleusingNavSync’sCW25receivermodule.TheinformationinthetablebelowidentifieskeysimilaritiesbetweenthetwoproductsaswellasadvantagesofferedbytheCW12.ThisdocumentwillalsoofferguidelinesonhowtoreplacetheM12withtheCW12,aswellashowtodesignintheCW12toanewapplication.

Feature M12 CW1212Channels Yes YesHighSensitivity No Yes1PPS Yes(500ns) Yes(10ns)VariableFreqOutput No Yes(NMEA0183)AntennaCurrentLimiting Yes YesVoltage 3V 3.0V-3.6VPositionaccuracy(3D) 25m 10mOn-boardbattery Yes(option) YesTRAIM Yes YesRTCM Yes YesDataOutputFormat NMEA0183(4800)or NMEA0183VariableBaudRateor MotorolaBinary(9600) MotorolaBinary(9600)

2.5 Auto Survey (timing versions only)TheAutomaticSiteSurveymodesimplifiessystemdesignforstatictimingapplications.Thisautomaticpositiondeterminationalgorithmisuserinitiatedandcanbedeactivatedatanytime. TheAutomaticSiteSurveyaveragesatotalof10minutesworthofvalid2Dand3Dpositionfixes.Iftheaveragingprocessisinterrupted,theaveragingresumeswhereitleftoffwhentrackingresumes.Oncethepositionissurveyed,theCW12automati-callyentersthePosition-HoldMode. Oncethesurveyiscompleted,theTimeRAIMalgorithmiscapableoferrordetection,isolation,andremoval.ThestatusoftheAutomaticSiteSurveyandPosition-HoldModeisretainedinRAMwhenthereceiverispowereddownonlyifbatterybackuppowerisprovided.

2.6 T-RAIM Algorithm (timing versions only)TimeReceiverAutonomousIntegrityMonitoring(RAIM)isanalgorithmintheCW12timingGPSreceiversthatusesredundantsatellitemeasurementstoconfirmtheintegrityofthetimingsolution. Thebasicideaisthatinmostsurveyingsystemsandinstruments,therearemoremeasurementstakenthanarerequiredtocomputethesolution.Theexcessmeasurementsareredundant.Henceasystemcanuseredundantmeasurementsinanav-eragingschemetocomputeasolutionthatismorerobustandaccuratethanusingonlytheminimumnumberofmeasurementsrequired.Onceasolutioniscomputed,themeasurementscanbeinspectedforerrors.ThisrepresentstheessenceofTimeRAIM.Inordertoperformprecisetiming,theGPSreceiverpositionisdeterminedandthenthereceiverisputintoposition-holdmodewherethereceivernolongersolvesforposition.Withthepositionknown,thetimeistheonlyremainingunknown.Inor-dertocomputethetime,theGPSreceiveronlyrequiresonesatellite.Ifmultiplesatellitesaretracked,thenthetimesolutionisbasedonanaverageofthesatellitemeasurements. Whentheaveragesolutioniscomputed,itiscomparedtoeachindividualsatellitemeasurementtoscreenforerrors.Aresid-ualiscomputedforeachsatellitebydifferencingthesolutionaverageandthemeasurement.Ifthereisabadmeasurementintheset,thentheaveragewillbeskewedandoneofthemeasurementswillhavealargeresidual.Ifthemagnitudeoftheresidu-alsexceedstheexpectedlimit,thenanalarmconditionexistsandtheindividualresidualsarechecked.Themagnitudeofeachresidualiscomparedwiththesizeoftheexpectedmeasurementerror.Iftheresidualdoesnotfallwithinadefinedconfidencelevelofthemeasurementaccuracy,thenitisflaggedasanerror.Onceanerrorisidentified,thenitisremovedfromthesolutionandthesolutionisrecomputedandcheckedagainforintegrity. WhentheT-RAIMalgorithmisenabled(usingthe@@GeMotorolaBinarycommand),theCW12basesthereportedT-RAIMStatusandSolution(@@HnMotorolaBinarymessage),fromthenumberofsatellitestrackedandthe1-sigmatimingaccuracyestimate(TACC).TheCW12iscapableofremovingfaultysatellitesfromthesolutionifthenumberofsatellitesinthesolutionis5ormore.Thereceivercancontinuetodetectfaultysatelliteswhilenumberofvisiblesatellitesis3ormore.Finallyifnumberofvisiblesatellitesis2orfewerneitherwouldbepossibleduetoscarceinformationavailable.



Figure 3 10-pin CW12 Connector

3. PHYSICAL CHARACTERISTICS

3.1 Electrical ConnectionsTheCW12receiveselectricalpowerandreceives/transmitsI/Osignalsthrougha10-pinpower/dataconnectormountedontheCW12.RefertoFigure2andTable2forpinposition,numberingandashortdescription.

Table 2: Signal Description of IO Connector on the CW12

¡¡¡¡¡¡¡¡¡¡

1 2

3 4

5 6

7 8

9 10

Pin Name I/O Description

1 TXD O NMEA0183outputfromGPSCore.RefertoCW25 UserManualfordescriptionofproprietarymessages orMotorolaBinaryinterface.

2 RXD I NMEA0183inputtoGPSCore.RefertoCW25User Manualfordescriptionofproprietarycommands orMotorolaBinaryinterface.

3 VCC PWR VoltageSupplyinput.3.0-3.6VDCtobesuppliedhere.

4 1PPS O 1PulsePerSecondoutput.Pulseis100uS(NMEA0183) or200mS(MotorolaBinary)indurationandrisingedge signifiestopofsecond.

5 GND PWR Powersupplyreturntoground.

6 VBATT PWR ~3Vneedstobesuppliedheretokeeptherealtime clockalivewhilethereceiverispoweredoff.

7 BOOTSEL I BootselectpinallowsFirmwaretobeupgradedwhengrounded.

8 RTCM I Notsupportedinthisversion.

9 ANT_SUPPLY PWR Powersupplyforactiveantennaused.Thevoltage appliedhereneedstoreflectthevoltageneededbythe antenna.Thissupplyislimitedto~50mAontheCW12-TIM.

10 FREQ_OUT O Programmablesynchronizedfrequencyoutputfrom GPScore,thisfrequencyis10MHzbydefaultbutmay bechangedbysendingaNMEAcommand.SeeCW25 UserManualfordetails.



3. Physical Characteristics continued

3.2 Interface ProtocolTheCW12receiverhasoneTTLserialdataport.Thisportisconfiguredasdatacommunicationsequipment(DCE)portandprovidesthemaincontrolanddatapathbetweentheCW12receiverandthesystemcontroller. TheI/Oportoperatesunderinterruptcontrol.IncomingdataisstoredinabufferthatisservicedbytheCW12receiver’sop-eratingprogram.Thisbufferisservicedevery16ms.TheCW12receiversupportseitherMotorolaBinaryorNMEA0138outputdataformat.

Format Motorola Binary NMEA 0138Type Binary ASCIIDirection In/Out In/OutPort 1 1BaudRate 9600 38400Parity None NoneDatabits 8 8Start/Stop 1/1 1/1

Table 3 CW12 Interface Protocol

4. OPERATING MODESForstandaloneoperationthereceiverwillperformcoldstartswithnopriorknowledgeofpositionorGPSsatellitedatasuchasalmanacsandephemerisprovidedtheantennahasaclearviewoftheskytoprovidesignalstrengthsof35dBorhigher.Thereceivershouldbeallowedtotracksatellitesforaminimumperiodof15minutestoensureallalmanacinformationhasbeenreceived.TheGPSdataisstoredintheEEPROMmemoryfittedtotheCW25.Oncethereceiverhasbeeninitializedandhascurrentalmanacandephemerisdataitmaythenbetakenindoorsfortestwithlowlevelsignals. Hotstarts(currentephemerisdataheldinEEPROM)canbeperformedwithlowlevelsignals(indoors).

5. POWER SUPPLY AND MANAGEMENTThepowersupplyrequirementsoftheCW12canallbeprovidedfromasingle3.6Vsupply.Tosimplifysystemintegrationon-boardregulatorsprovidethecorrectvoltagelevelsfortheRFandoscillator(2.9Vor3.0V)andlowvoltagedigitalcore(1.8V).IfthesourceimpedanceofthepowersupplytotheCW12ishighduetolongtracks,filteringorothercauses,localdecouplingofthesupplysignalsmaybenecessary.CareshouldbetakentoensurethatthemaximumsupplyrippleatthepinsoftheCW12is50mVpeaktopeak. TheCW12GPSreceiverisalowpowermoduleconsuminglessthan250mWfora1Hzupdateofposition.Thereceivercontainssoftwaretodynamicallyreducepowerconsumptionwhereverpossible.Wherechannelsandtapsarenotneededtheyareswitchedoff.Whentheprocessorisnotrequireditisputintoahaltuntilinterruptstateandthechipsclocksystemisgeareddowntoreducepowerconsumption.Allofthesethingsareperformedautomaticallywithoutanyuserconfiguration.IffurtherpowersavingisrequiredthereceivercanbereprogrammedwithsmallerGPSconfigurationstherebypermanentlyswitchingoffportionsoftheGPShardwareandallowingtheprocessorspeedtobereduced,therebysavingpower. ForbatterypoweredapplicationswhichneedtoreducethepowerconsumptionitispossibletoswitchthereceiverintoComaMode.ThisconfigurestheRFfrontendintosleepmode,switchesoffinternalperipheralsandplacestheprocessorinasleepstatewaitingforaninterrupt.Powerconsumptionistypicallyreducedto<30mW. ComaModeisinitiatedthroughtheCOMAserialcommand,detailsofwhichcanbefoundinsection6.2.3.9.

6. COMMUNICATIONS PROTOCOLSFulldescriptionsofthecommunicationsprotocolsusedbytheCW12canbefoundinsection6.2.1(MotorolaBinary)and6.2.2(NMEA).



6.1 Port ConfigurationThereisonlyoneserialportavailableontheCW12.ThisportwillsupporteitherMotorolaBinaryorNMEA0138dataflowfor-matsbutnotboth.ThechosenprotocolishardcodedintotheCW12firmwareandcannotbechangedonlyifadifferentfirm-wareisflashed.

Port TX Pin RX Pin Baud Rate Function1 1(default) 2(default) 9600 MotorolaBinaryFormat1 1(specialbuild) 2(specialbuild) 38400 NMEA

Allportsareconfiguredas8,bitsnoParity,withnohandshaking.

6.2 Output FormatTherearetwotypesofmessagesthatcanbeoutputfromtheCW12receiver,thesearesplitintoMotorolaBinarymessagesandNMEAsentences.OnlyNMEAoutputrepresentsASCIIstrings.

6.2.1 Motorola Binary FormatThebinarydatamessagesusedbytheGPSreceiverconsistofavariablenumberofbinarycharacters.ThesebinarymessagesbeginwiththeASCII@@charactersandareterminatedwiththeASCIIcarriagereturnandlinefeed<CR><LF>.Thefirsttwobytesafterthe@@charactersaretwoASCIIcharactersthatidentifytheparticularstructureandformatoftheremainingbinarydata.Thebyteprecedingthetermination<CR><LF>ofallmessagesisasinglebytechecksum(theexclusive-orofallmessagebytesafterthe@@andbeforethechecksum).

Everymessagehasthefollowingcomponents:• Message Start: @@ (two hex 40s) denotes start of binary message.• Message ID: (A..Z)(a..z, A..Z) ASCII upper-case letter, followed by an ASCII lower-case or upper case letter. These two characters together identify

the message type and imply the correct message length and format.• Binary Data Sequence: Variable number of bytes of binary data dependent on the command type.• Checksum: C The exclusive-or of all bytes after the @@ and prior to the checksum.• Message Terminator: <CR><LF> carriage return and line feed denoting the end of the binary message.

EveryGPSreceiverinputcommandhasacorrespondingresponsemessagesothattheusercandeterminewhethertheinputcommandshavebeenacceptedorrejectedbytheGPSreceiver.

Theusermusttakecaretocorrectlyformattheinputcommand.Payparticularattentiontothenumberofparametersandtheirvalidranges.Aninvalidmessagecouldbeinterpretedasavalidunintendedmessage.Abeginning@@,avalidchecksum,aterminatingcarriagereturnlinefeed,thecorrectmessagelengthandvalidparameterrangesaretheonlyindicatorsofavalidinputcommandtotheGPSreceiver.Formulti-parameterinputcommands,theGPSreceiverwillrejecttheentirecommandifoneoftheinputparametersisoutofrange.

Inputandoutputdatafieldscontainbinarydatathatcanbeinterpretedasscaledfloatingpointorintegerdata.ThefieldwidthandappropriatescalefactorsforeachparameteraredescribedintheindividualI/Omessageformatdescriptions.Polarityofthedata(positiveornegative)isdescribedviathetwo’scomplementpresentation.

InputcommandmessagescanbestackedintotheGPSreceiverinputbuffer,uptothedepthofthemessagebuffer.TheGPSreceiverwilloperateonallfullmessagesreceivedandwillprocessthemintheordertheyarereceived.Previouslyscheduledmessagesmaybeoutputbeforetheresponsestothenewinputcommands.

Everyinputcommandhasacorrespondingoutputresponsemessage.ThisenablestheusertoverifythattheGPSreceiveracceptedtheinputcommand.TheGPSreceiverresponsetoproperlyformattedcommandswithatleastoneout-of-rangeparameteristoreturnthepreviousunchangedvalue(s)oftheparameter(s)intheresponsemessage.

Forthecasewheremorethanoneoutputmessageisscheduledduringthesameonesecondinterval,theGPSreceiverwilloutputallscheduledmessagesbutwillattempttolimitthetotalnumberofbytestransmittedeachsecondto750bytes.

ForthepurposeoftestingtheCW12’sMotorolaBinarycommandsandmessageswehaveusedtheMotorola’sWinOnCorev1.2.Formoreinformationontheabovementionedsoftwarepleaseconsulttheapplication’susermanualorhelpfiles.



6. Communications Protocols continued

6.2.1.1 One Pulse Per Second (1PPS) TimingTherisingedgeofthe1PPSsignalisthetimereference.Thefallingedgewilloccurapproximately200ms(±1ms)aftertherisingedge.Thefallingedgeshouldnotbeusedforaccuratetimekeeping.

Theposition/status/datamessageandthetimeRAIMsetupandstatusmessagearetheonlyoutputmessagescontainingtimeinformation.Ifenabled,thesemessageswillbeoutputfromthereceivershortlyaftertherisingedgeofthe1PPSsignal.Generally,thefirstdatabyteinthefirstmessagewillbeoutputbetween0to50msafter.Fortheposition/status/datamessage,thetimeoutputinthemessagereflectsthebestestimateofthemostrecentmeasurementepoch.AsimpletimingdiagramisshowninFigure4.

Figure 4 IPPS Output Signal Timing

6.2.1.2 1PPS Cable Delay Correction and 1PPS Offset Userscancompensateforantennacablelengthwiththe1PPSCableDelayCommand(@@Az).The1PPScanalsobepositionedanywhereintheonesecondwindowusingthe1PPSOffsetcommand(@@Ay).Therisingedgeofthe1PPSisplacedsothatitcorrespondstothetimeindicatedbythefollowingequation:

1PPS rising edge time = top of second -1PPS cable delay + 1PPS offset

Considerthefollowingexample: TrueTopofsecond=10.000000000s 1PPScabledelaycorrection=0.000654321s 1PPSoffset=0.100000000s 1PPSrisingedgetime=10.099345679s

Therisingedgeofthe1PPSsignalisadjustedsothatitoccurscorrespondingtothefractionalpartoftimeequaltothetotalabove.ThefractionalpartoftimeismeasuredrelativetoUTCorGPStimedependingonthesettingoftheTimeMode.




6.2.1.3 Supported Motorola Binary I/O commands

Command Name Default Comments@@Ag SatelliteMaskAngle 0 @@Am SatelliteIgnoreList none @@As Position-HoldPosition 0,0,0 GPSonly@@Aw UTCTimeCorrection Enabled @@Ay 1PPSOffset n/a@@Az 1PPSCableDelay n/a@@Bb VisibleSatellites Outputoff @@Bd AlmanacStatus Polledonly@@Be AlmanacDataOutput Outputoff Nosupportforpages4/25and5/25– PolledonlyResponseis@@Cb@@Bf EphemerisDataInput Outputoff Responseis@@Cc@@Bi EphemerisDataOutput Outputoff Polledonly@@Bo UTCOffsetStatus Outputoff Polledonly@@Bp RequestUTC/IonosphericData Outputoff Polledonly@@Cb AlmanacDataInput n/a Output-responsetoBeorInput-responseisCh@@Cc EphemerisDataResponse n/a Responseto@@Bf@@Cf Settodefaults n/a @@Ch AlmanacDataResponse n/a Responseto@@Cb@@Cj ReceiverID n/a ProvidesinformationonSoftwareLoad; Nouniqueserialormanufacturedata@@Eq ASCIIPosition n/a Nodifferentialsupport@@Ga CombinedPosition 0,0,0 GPSonly@@Gb CombinedTime 12:00:00,1/1/98,0:0 @@Gc 1PPSControl 1PPSalwayson@@Gd PositionControl Nohold @@Ge T-RAIMSelectMessage Disabled @@Gf T-RAIMAlarmMessage 1000ns @@Gj LeapSecondStatus n/a @@Gk IDTagMessage n/a NotinitializedtoserialNotusedincommands@@Ha Position/Status/Data Messageoff IDTagnotusedNoantennastatus@@Hb ShortPositionMessage Messageoff IDTagnotusedNoantennastatus@@Hn 12ChannelT-RAIMStatusMessage Messageoff @@Ia Self-Test n/a Verylimitedsupport:OnlyFLASHandROMtested NosupportforantennastatusDoesnotcheck RTC/Temperature/Correlator@@Sz SystemPower-OnFailure n/a

Table 4 GPS Receiver Supported Binary Messages




6.2.1.3.1 Satellite Mask Angle Message (@@Ag) TheGPSreceiverwillattempttotracksatellitesforwhichtheelevationangleisgreaterthanthesatellitemaskangle.Thisparameterallowstheusertocontroltheelevationanglethatisusedforthisdecision.

Range:0to89degrees

Default:0degrees

QuerycurrentSatelliteMaskAngle:

@@AgxC<CR><LF>

where:x= 1‘0xFF’hexbyte

0xD9=checksum

Messagelength:8bytes

ChangecurrentSatelliteMaskAngle:

@@AgdC<CR><LF>

where: d=degrees0..89degrees(0x00–0x59)

C=checksum


Responsetoeithercommand:

@@AgdC<CR><LF>

where: d=degrees0..89degrees(0x00–0x59)

C=checksum


WinOnCore – Command Monitor Window

(Tx)@@Ag 20

(Rx)@@Ag 20

WinOnCore – Additional Message Window

———————————————————————————

@@Ag (Satellite Mask Angle) command...

———————————————————————————

Satellite Mask Angle

Mask Angle: 32 degrees




6.2.1.3.2 Satellite Ignore List Message (@@Am)

Itisusefultohavetheflexibilitytodeleteparticularsatelliteidentificationnumbersfromtheselectionprocess.TheGPSreceiverincludes,initslistofsatellitestotrack,allsatellitesthatarehealthyandinthealmanac.TheusercanselecttoignoreparticularsatellitesinthealmanacbyissuinganIgnoreSatelliteCommand.Inaddition,theusercanrestoreanypreviouslyignoredsatelliteIDsbyissuinganIncludeSatelliteCommand.Theusermaynoticeadelaybetweenissuingthiscommandandtheactualremovalorinclusionofparticularsatellites.

Defaultvalue:AllsatelliteSVIDsincluded.

QuerycurrentSVIgnoreList:

@@AmxxxxxC<CR><LF>

where:xxxxx=5bytes,all0x00

0x2C=checksum


ChangecurrentSVIgnoreList:

@@AmkssssC<CR><LF>

where:k=0x00-fixedhexconstant

ssss=32bitbinaryfield,eachbitrepresentingoneSVID.(msb=SVID32,lsb=SVID1)

1=Ignore

0=Include

C=checksum


ResponseMessagetoeithercommand:

@@AmkssssC<CR><LF>

where:k=0x00fixedhexconstant

ssss=32bitbinaryfield,eachbitrepresentingoneSVID.(msb=SVID32,lsb=SVID1)

1=Ignore

0=Include

C=checksum



(Tx)@@Am 0023E9163A

(Rx)@@Am 0023E9163A

willaddthefollowingsatellitestotheignorelist:

SV: 30;26;25;24;23;22;20;17;13;11;10;6;5;4;2


———————————————————————————

@@Am (Satellite Ignore List) command...

———————————————————————————

Satellite Ignore List

Satellite Ignore List: 23E9163Ah




6.2.1.3.3 Position Hold Parameters Message (@@As)TheusercanspecifyPositionHoldcoordinatesbothfortimingapplicationstoincreasethetimingaccuracy.Thiscommandisusedtoenterthepositiontobeheld.

Thepositionisspecifiedinthesameunitsandreferencedtothesamedatumastheinitialpositioncoordinatesoflatitude,longitudeandheight.TheheightparameterisreferencedtotheGPSreferenceellipsoid.Notethatallthreeparametersmustbespecified.ThevalidrangesofeachparameterarethesameasthosespecifiedintheCombinedPositionMessage(@@Ga).

ThiscommandwillonlybeexecutedifPositionHoldisdisabled.PositionHoldiscontrolledusingthe@@Gdmessage.

Defaultvalues: Latitude=0°(Equator) Longitude=0°(GreenwichMeridian) Height=0m(GPSHeight)

QuerycurrentPosition Hold Parameters:@@AsxxxxxxxxxxxxxC<CR><LF>

where: xxxxxxxxxxxxx=13outofrangehexbytes:0xFF C=0xCD


ChangecurrentPositionHoldParameters:

@@AslllloooohhhhtC<CR><LF>

where: llll=latitudeinmas-324,000,000..324,000,000(-90º..90º) oooo=longitudeinmas-648,000,000..648,000,000(-180º..180º) hhhh=heightincm-100000..1,800,000(-1,000.00..18,000.00m) t=heighttype0=GPSheight C=checksum


Responsetoeithercommand:@@AslllloooohhhhtC<CR><LF>

where: llll=latitudeinmas-324,000,000..324,000,000(-90º..90º) oooo=longitudeinmas-648,000,000..648,000,000(-180º..180º) hhhh=heightincm-100000..1,800,000(-1,000.00..18,000.00m) t=heighttype0=GPSheight C=checksum



FirstofallwedisableHoldPositionandthenweinputthepositionholdparameters.

(TX)@@Gd 00

(RX)@@Gd 00

(Tx) @@As 0B1D41730023F87A0000880600

(Rx) @@As 0B1D41730023F87A0000880600


———————————————————————————

@@As (Hold Position Parameters) command...

———————————————————————————

Hold Position Parameters

Latitude: 51.796284 degrees

Longitude: 0.654825 degrees

Height: 348.220000 m Type: 0 (0 - GPS, 1 - MSL)




6.2.1.3.4 Time Correction Select (@@Aw)Thiscommandselectsthetimereference(eitherGPSorUTC)usedinthe@@Ha12ChannelPosition/Status/Dataand@@HbShortPositionMessages.ThisTimecommandisalsousedtodeterminethesynchronizationpointforthe1PPStimingpulse.

IfthereceiverhasnotdownloadedtheUTCparametersportionofthealmanac,thereceiverwilloutputtimeequaltoGPStimeandaflagdenotingthelackofUTCparameterswillbesetinthe@@Hamessage.OncethereceiverhasdownloadedtheUTCparametersfromthesatellitesthereceiverwillautomaticallyswitchthetimereferencetoUTCifUTCmodeisselected.

Defaultmode:UTC

ChangecurrentUTCTimeCorrectionOption:

@@AwmC<CR><LF>

where: m=timemode: 0x00=GPS 0x01=UTC

C=checksum


Responsetoeithercommand:

@@AwmC<CR><LF>

where: m=timemode: 0x00=GPS

0x01=UTC

C=checksum



(TX)@@Aw 00

(RX)@@Aw 00


———————————————————————————

@@Aw (Time Mode) command...

———————————————————————————

Time Mode

Mode: 0

(0 - GPS, 1 - UTC)

Forexample:

1. Set@@Ha01-Position/StatusDataoutputeachsecond.

2. Set@@Aw00–GPStime

3. Observethetime

4. Set@@Aw01–UTCtime

5. Observethetimeandnoticethe14secondoffsetbetweentheGPSandUTCtime. (Note:Whenthisusermanualwaswrittentherewasa14secondsoffsetbetweentheGPSandUTCtime.)




6.2.1.3.5 1PPS Time Offset Command (@@Ay) TheCW12outputsaonepulse-persecond(1PPS)signalwiththerisingedgeplacedontopoftheUTCorGPSonesecondticmark,dependingonwhichtimereferencehasbeenselectedbytheuser.The1PPSTimeOffsetcommandallowstheuserofCW12timingreceiverstooffsetthe1PPStimemarkinonenanosecondincrements.Thisoffsetcanbeusedtoplacethe1PPSsignalanywherewithintheonesecondepoch.

Theresolutionofthisparameterisonenanosecond.Thisdoesnotimplythatthe1PPSoutputbytheCW12isaccuratetothislevel.Thiscommandonlyallowstheusertochangethelocationoftheaverageplacementofthepulse.

TheabsoluteaccuracyofthesignalisafunctionofGPStimeaccuracy,andissubjecttodegradationduetoU.S.DepartmentofDefensepolicy.

Range:0.000000000to0.999999999sDefaultvalue:0.000000000sResolution:1ns

Querycurrent1PPSTimeOffset:@@AyxxxxC<CR><LF>

where:

xxxx=4outofrangehexbytes:0xFF

C=0x38


Changecurrent1PPSTimeOffset:@@AyttttC<CR><LF>

where:

tttt=timeoffsetinns0..999,999,999(0.0to0.999999999s)

C=checksum


Responsetoeithercommand:@@AyttttC<CR><LF>

where:

tttt=timeoffsetinns0..999,999,999(0.0to0.999999999s)

C=checksum



(Tx)@@Ay 004C4B40

(Rx)@@Ay 004C4B40


———————————————————————————

@@Ay (1PPS Offset) command...

———————————————————————————

1PPS Offset

Time Offset: 5000000 ns




6.2.1.3.6 1PPS Cable Delay Correction Command (@@Az) TheCW12timingreceiveroutputsa1PPSsignal,therisingedgeofwhichisplacedatthetopoftheGPSorUTConesecondtimemarkepochasspecifiedbytheTimeModecommand.The1PPSCableDelayCorrectioncommandallowstheusertooffsetthe1PPStimemarkinonenanosecondincrementsrelativetothemeasurementepoch.

ThisparameterinstructstheGPSreceivertooutputthe1PPSoutputpulseearlierintimetocompensateforantennacabledelay.Uptoonemillisecondofequivalentcabledelaycanberemoved.Zerocabledelayissetforazero-lengthantennacable.Theusershouldconsultacabledatabookforthedelayperunitlengthfortheparticularantennacableusedinordertocomputethetotalcabledelayneededforaparticularinstallation.

Thisparametermayalsobeemployedbytheusertoadjustthepositionofthe1PPStocompensateforothersystemdelays.

Range:0.000to0.000999999s

Defaultvalue:0.000s

Resolution:1ns

Querycurrent1PPSCableDelayCorrection:@@AzxxxxC<CR><LF>

where:

xxxx=4outofrangehexbytes:0xFF

Checksum=0x3B


Changecurrent1PPSCableDelayCorrection:@@AzttttC<CR><LF>

where:

tttt=timeoffsetinns0..999,999ns(0.0to0.000999999s)

C=checksum


Responsetoeithercommand:@@AzttttC<CR><LF>

where:

tttt=timeoffsetinns0..999,999ns(0.0to0.000999999s)

C=checksum



(Tx)@@Az 0000C350

(Rx)@@Az 0000C350


———————————————————————————

@@Az (1PPS Cable Delay) command...

———————————————————————————

1PPS Cable Delay

Time Offset: 50000 ns



6. Communications Protocols continued 6.2.1.3.7 Visible Satellite Data Message (@@Bb)

Thiscommandrequeststheresultsofthemostcurrentsatellitevisibilitycomputation.Theresponsemessagegivesasummaryofthesatellitevisibilitystatusshowingthenumberofvisiblesatellites,theDopplerfrequencyandthelocationofthecurrentlyvisiblesatellites.Thereferencepositionforthemostrecentsatellitealertisthecurrentpositioncoordinates. NotethatthesecoordinatesmaynotcomparetotheGPSreceiver’sactualpositionwheninitiallyturnedon,sincetheGPSreceivermayhavemovedagreatdistancesinceitwaslastused.Defaultmode:Polled

QueryCurrentVisibleSatelliteData:@@BbmC<CR><LF> where: m=mode0x00=outputresponsemessageonce(polled)0x01=outputresponsemessagedata whenvisibilitydatachanges(approximatelyonceevery5-7seconds)–(Theabovedescriptionis notsupportedbytheCW12GPSreceiver.TheCW12supportsonlythepolledmodeorcontinuous mode.Howeverthedescriptionhasbeenkeptinordertopreservetheconsistencywiththe MotorolaM12usermanual.) C=checksum Messagelength:8bytes

Responsetoabovecommand:@@BbniddeaasiddeaasiddeasiddeaasiddeaasiddeaasiddeaasiddeaasiddeaasiddeaasiddeaasiddeaasC<CR><LF> where: n=numberofvisiblesats0..12 Foreachvisiblesatellite,uptonfieldscontainthefollowingvaliddata i-satelliteID1..32 dd-DopplerinHz-5000..5000 e-elevationindegrees0..90 aa-azimuthindegrees0..359 s-satellitehealth0=healthyandnotremoved 1=unhealthyandremoved C=checksum Messagelength:92bytes


(Tx)@@Bb 00(Rx)@@Bb 0FFD70080042000E16D80A0069000804530D0121001C168B14013E000301102F008100000000000000001B01 E104010A001606062B0043000B15AC2800FD0000000000000000130A9E57009A0012FF500E002700

WinOnCore – Additional Message Window———————————————————————————@@Bb (Visible Satellite Status) command...———————————————————————————Visible Satellite Status Visible Satellites: 10 Satellite details found in Azimuth & Elevation Window

Figure 5 WinOncore’s Azimuth and Elevation Window




6.2.1.3.8 Almanac Status Message (@@Bd)ThiscommandrequestsalmanacstatusinformationcorrespondingtothesatellitealmanacdatacurrentlystoredinRAM.TheGPSreceivercontinuallycapturesacompletenewalmanactointernalRAMwhiletrackingsatellites.IfanexistingalmanacisstoredinRAMonpower-up,satellitevisibilityinformationwillbeavailableimmediately.IfnoalmanacdataisstoredinRAMonpower-up,thereceiverwilldownloadanewalmanacandthencomputesatellitevisibilityinformation.

QueryCurrentAlmanacStatus:@@BdmC<CR><LF>

where:

m=mode0x00=Outputstatusonce(polled) 0x01=OutputstatuswhenRAMalmanacdatachanges.(Theabovefunctionalityis nosupportedbytheCW12GPSreceiver.TheCW12supportsonlythepolledmode orcontinuousmode.Howeverthedescriptionhasbeenkeptinordertopreservethe consistencywiththeMotorolaM12usermanual.)

C=checksum


Responsetoabovecommand:@@BdvwtassssrrrrrrrrC<CR><LF>

where:

v=almanacvalidflag 0x00=noalmanacinreceiver 0x01=validalmanacinreceiver w=almanacweeknumber(raw)0x00..0xFF(ICD-GPS-200) t=timeofalmanac(raw)0x00..147(ICD-GPS-200) a=numberofavailableSVs0x00..0x20 ssss=SVsinalmanac32bit(2byte)binaryfield,eachbitrepresentsoneSVID (msb=SVID32;1sb=SVID1) rrrrrrrr=8reservedbytes

C=checksum



(Tx)@@Bd 00

(Rx)@@Bd 015A471D7FFFEFFE0000000000000000


———————————————————————————

@@Bd(AlmanacStatusMessage)command...

———————————————————————————

Almanac Status Message

Almanac Valid Flag: 1 (0 - No Almanac, 1 - Valid Almanac)

Almanac Week: 90

Time of Almanac: 71

SVs in Almanac: 1D7FFFEFh




6.2.1.3.9 Almanac Data Request (@@Be - response is Cb)ThiscommandisusedtocommandtheCW12tooutputitscurrentalmanacdata.Theuserhastheoptionofrequestingthealmanacdataoutputonetime(polled),oreachtimethealmanacdatachanges.(TheabovefunctionalityisnosupportedbytheCW12GPSreceiver.TheCW12supportsonlythepolledmodeorcontinuousmode.HoweverthedescriptionhasbeenkeptinordertopreservetheconsistencywiththeMotorolaM12usermanual.)

AlmanacdatafortheGPSsatellitesistransmittedinwords3through10ofsubframe5(pages1through25),andwords3through10ofsubframe4(pages2through5,7through10,and25)ofthesatellitebroadcastdatamessage.RefertotheICD-GPS-200foradetailedalmanacdatadescription.

TheCW12outputsthealmanacdatathroughaseriesofoutputmessages,eachofwhichisidentifiedbytheparticularsubframeandpagenumbers.Thedatafieldsofeachindividualmessagecorrespondtowords3through10ofthebroadcastdata.Eachwordcontains24databits.

Theentirealmanacdataoutputconsistsof34outputresponsemessagescorrespondingtothe25pagesofsubframe5andthe9pagesinsubframe4thatcontainalmanacdata(pages2through5,7through10,and25).Thetotalmessageoutputforoneoutputrequestis1122bytesincludingthe@@Cbprefixandthechecksum,carriagereturn,andlinefeedforeachoutput.Theoutputmessagebeginswithsubframe5page1.

TheCW12willoutputabout750bytesofmessagedataforeachone-second-outputopportunity.Ifselected,thealmanacresponsemessageisoutputuntilthetotalnumberofbytessentinaonesecondepochexceeds750.Theremainderofthealmanacmessageissentinthenextonesecondepoch(uptothe750bytelimitpersecond)untiltheentirealmanacdataisoutput.

Iftheuserissuesthiscommandandthereceiverdoesnotcontainanalmanac,thereceiverreturnsoneresponsemessagewiththesubframeandpagebytesequaltozero.

SomeoftheabovefunctionalityisnotsupportedbytheCW12GPSreceiver,namelyoursolutiondoesn’toutputsubframe4page25andsubframe5page25.Formorereferencesregardingtheinformationcontainedinthosepagespleaseconsult“InterfaceSpecification,ICD-GPS-200,RevisionD,IRN-200D-001,7March2006”.AlsoCW12supportsonlythepolledmode.HoweverthepreviousdescriptionhasbeenkeptinordertopreservetheconsistencywiththeMotorolaM12usermanual.

Defaultmode:Polled


(Tx)@@Be 01

(Rx)@@Cb 05014132D97B1D7CFD7700A10D3287040DBA28FB1DC9EE060027

(Rx)@@Cb …………………………………………………………………………………..


———————————————————————————

@@Be (Almanac Data Output Message) command...

———————————————————————————

Almanac Data Output

Subframe 5, Page 1

———————————————————————————

Almanac Data Output

………………………




6.2.1.3.10 Almanac Data Input (@@Cb response is @@Ch)ThiscommandallowstheusertoloadapreviouslyrecordedalmanacintotheCW12’sRAMviatheserialport.Theentirealmanacdatamessageconsistsof34uniqueformattedmessagesthatcorrespondtothesubframeandpagenumberofthealmanacdata(see“InterfaceSpecification,ICD-GPS-200,RevisionD,IRN-200D-001,7March2006”forformatdescription). Itisnotnecessarytoinputanalmanacatpowerup.Ifbackuppowerhasbeenapplied,thealmanacwillberetainedinRAM.Ifthealmanacisnotavailable,itwillbedownloadedfromthesatellites.Thiscantakeanywherefrom15to30minutesifsatellitesaretrackedcontinuously. ManuallyloadinganalmanacusingthiscommandwillreducetheTTFF.Thereceiverechoestheinputalmanacdatasubframeandpagenumbersofmessagesreceivedsotheusercanvalidatethateachalmanacslicehasbeenaccepted.Itisnotnecessarynorisitrecommendedtowaitforanechobeforesendingthenextdatapage.TheM12+receiverwillcollectanentirealmanacinlocalstorage,andthencheckthealmanacforvalidity.Thereceiverwillupdatetheinternalalmanacdatawiththenewuser-suppliedalmanacuponcompletionofthereceiptofavalidalmanac.AsopposedtotheimplementationaboveourfirmwarewillsavetotheNetAssistRAMareaeverytimetheCW12receivesacorrectalmanacsubframepage.PreviousdescriptionhasbeenkeptinordertopreservetheconsistencywiththeMotorolaM12usermanualandunderlinethedifferencebetweentheirimplementationandours. Anysingleinputmessagethathasaninvalidsubframe(i.e.,not4or5)willresetthealmanaccollectionsoftwaresothatthelocalcollectionofalmanacdatacanbeginfresh.Iftheinputmessagehasaninvalidsubframe(i.e.,not4or5)willbeignoredandtoreplywillbegiven.Subframe5,Page1marksthebeginningmessageandresetsthecollectionprocess.ThedataforSubframe5,Page1mustappearfirstinthestringof34commandsthatmakeupthetotalalmanacinputdata.AsopposedtotheMotorolaimplementationCW12doesn’ttakeintoconsiderationtheorderinwhichtheuserissendingthealmanacdata,soifSubframe5,Page1issentanywhereexceptfirstmessageitisproperlyinterpretedandsaved. Theorderfortheremainingdataisnotimportant.Theusercaninsertuptoabout1Kofdatapersecondintotheserialport.Consequently,theusershouldbeawarethatthe34totalmessages(of33byteseach)thatmakeupthealmanacdatawilltakelongerthanonesecondtoinputintothereceiver.

InputOneAlmanacDatapage:@@Cbspxxx…xxxC<CR><LF> where: sp=subframe/pagesubframe5/pages1-25,orsubframe4/pages2-5,7-10, xxx…xxx=datawordswords3-10,eachwordis3byteslong(formatperICD-GPS-200) C=checksum Messagelength:33bytes

Responsetoabovecommand:@@ChspC<CR><LF> where: sp=subframe/pagesubframe5/pages1-25,orsubframe4/pages2-5,7-10,25 C=checksum Messagelength:9bytes


(Tx)@@Cb 04085E48227B011BFD3200A10D9CD9596434A8658ECDB11201DB(Rx)@@Ch 0408


———————————————————————————@@Cb (Almanac Data Output) command...———————————————————————————Almanac Data Input Subframe 4, Page 8




6.2.1.3.11 Ephemeris Data Output Message (@@Bi response @@Bf )Thisparameterdeterminestheratethatsatelliteephemerisdataisoutput.Theuserhastheoptionofrequestingtheephemerisdataoutputonetime(polled),oreachtimethesatelliteephemerisdatachanges(continuously).ThecommandedsatelliteephemerisdataoutputrateisstoredinRAMandisretainedbetweenpowercyclesifbackupbatterypowerisapplied.TheCW12supportsonlythepolledmode.ThepreviousdescriptionhasbeenkeptinordertopreservetheconsistencywiththeMotorolaM12usermanual.

EphemerisdataforeachoftheGPSsatellitesiscontainedinsubframes1,2,and3,words3through10.Eachsatellitetransmitstheephemerisdataforitselfonly.Theuserisdirectedtothe“InterfaceSpecification,ICD-GPS-200,RevisionD,IRN-200D-001,7March2006”forspecificsontheformatoftheephemerisdata.

Whenpolled,theCW12outputsacompleteEphemerisDataOutputMessageforeachofthesatellitesthatthereceiveriscurrentlyusingforpositionfix.

TheGPSreceiveroutputstheephemerisdatathroughaseriesofoutputmessages,eachofwhichcorrespondstoaparticularsatellite.Thedatafieldsofeachmessagecorrespondtowords3through10ofsubframes1through3asdefinedin“InterfaceSpecification,ICD-GPS-200,RevisionD,IRN-200D-001,7March2006”.Eachwordcontains24databits.

TheGPSreceiverwilloutputabout750bytesofmessagedataforeachone-secondoutputopportunity.Ifselected,theephemerisresponsemessageisoutputforeachsatellitethatiscurrentlytrackeduntilthetotalnumberofbytessentduringaone-secondepochexceeds750.Theremainderoftheephemerismessageissentduringthenextone-secondepoch(uptothe750bytelimitpersecond)untilalloftheephemerisdataforallsatellitesisoutput.

Input@@BimC<CR><LF>Requestalmanacdata

mmode0-outputresponsemessageonce(polled)

1-outputresponsemessagewhenephemerisdatachanges(continuous)

Output@@Bfixxx..xxxC<CR><LF>

iSVID1..32

xxx..xxxephemerissubframe1-3/words3-10(72bytespersatellite)


(Tx)@@Bi 00

(Rx)@@Bf 015F5203000F30261D1EE2D58A7095F9475EEC0000120C7EFD47FB9029DED6E6D9BAFC61 036B846213B8A10DD14F5EEC7DFFD2D4953848004B284E186A1AD7B7C4C451FFAAF34704C5


Ephemeris Data

SVID: 1

Ephemeris: 5F520300h




6.2.1.3.12 Ephemeris Data Input (@@Bf response @@Cb)Thiscommandwillcausethereceivertoacceptsatelliteephemerisdatainputviacommunicationsport1.ThereceiverkeepstheephemeridesdecodedfromallsatellitesinRAM,aslongasbackupvoltageisappliedtothereceiverandtheephemeridesarestillvalid(t-toe<4hours).

Thereceiverechoestheinputephemerisdataformatmessagesotheusercanvalidatetheephemerisdatawiththenewusersuppliedephemerisuponcompletionofthereceiptofavalidephemeris.

InputEphemerisData:@@Bfi[24x{eee}]C<CR><LF>

where:

i=SVID0x01..0x25

eee...eee=ephemerissubframesf1–3,words3-10(72bytespersat;formatper “InterfaceSpecification,ICD-GPS-200,RevisionD,IRN-200D-001,7March2006”)

C=checksum


Responsetoabovecommand:@@Cci[24x{eee}]C<CR><LF>

where:

i-SVID0x01..0x25

eee...eee=ephemerissubframesf1-3,words3-10(72bytespersat;formatper “InterfaceSpecification,ICD-GPS-200,RevisionD,IRN-200D-001,7March2006”)

C=checksum



(Tx)@@Bf015F5203000F30261D1EE2D58A7095F9475EEC0000120C7EFD47FB9029DED6E6D9BAFC6103 6B846213B8A10DD14F5EEC7DFFD2D4953848004B284E186A1AD7B7C4C451FFAAF34704C5

(Rx)@@Cc015F5203000F30261D1EE2D58A7095F9475EEC0000120C7EFD47FB9029DED6E6D9BAFC6103 6B846213B8A10DD14F5EEC7DFFD2D4953848004B284E186A1AD7B7C4C451FFAAF34704C5


@@Bf (Ephemeris Data) command...

———————————————————————————

Ephemeris Data Input Response

Ephemeris Input for Satellite: 1




6.2.1.3.13 UTC Offset Output Message (@@Bo)ThismessageallowstheusertorequesttheUTCoffsetthatiscurrentlybeingusedinthetimesolution.ThevaluereportedistheintegernumberofsecondsbetweenUTCandGPStime.IftheoffsetreportedbythereceiveriszeroandUTCistheselectedtimereference,thereceiverdoesnotcurrentlyhavetheportionofthealmanacthatcontainstheUTCparameters.

TheUTCparametersarebroadcastbythesatellitesaspartofthealmanac,whichisrepeatedevery12.5minutes.Themessagecanbesettooutputeitheronce(polled),oranytimetheUTCoffsethasbeenupdatedorchangedfromitspreviousvalue.

Defaultmode:Polled

RequestCurrentUTCOffset:@@BomC<CR><LF>

where:

m=mode0=outputUTCoffsetonce(polled)

1=outputUTCoffseteverytimeitisupdated

C=checksum


Responsetoabovecommand:@@BouC<CR><LF>

where:

u=UTCoffsetinseconds-128..+127

C=checksum



(Tx)@@Bo 00

(Rx)@@Bo 0E


———————————————————————————

@@Bo (UTC Offset Message) command...

———————————————————————————

UTC Offset Message

UTC Offset: 14 s

(Note: When this user manual was written there was 14 seconds offset between the GPS and UTC time.)




6.2.1.3.14 Request UTC/Ionospheric Data (@@Bp)ThismessageallowstheusertorequestUTCandionosphericdatadecodedfromtheNavigationDataMessage.CW12supportsonlythepoolmode.Defaultmode:Polled

RequestCurrentUTC/IonosphericData:@@BpmC<CR><LF> where: m=mode0=outputresponseonce(polled) 1=outputresponsewheneitherUTCorionosphericdatachanges.(TheCW12supportsonly polledmode,howeverthepreviousdescriptionhasbeenkeptinordertopreservetheconsistency withtheMotorolaM12usermanual.) C=checksum Messagelength:8bytes

Responsetoabovecommand:@@CoabcdefghAAAAaaaadtwWnDC<CR><LF> where: a,b,c,d,e,f,g,andh=IonosphericData(seeICD-GPS-200,Table20-Xforscalefactors) a=a0-128…+127seconds b=a1-128…+127seconds/semi-circle c=a2-128…+127seconds/(semi-circle)2 d=a3-128…+127seconds/(semi-circle)3 e=b0-128…+127seconds f=b1-128…+127seconds/(semi-circle) g=b2-128…+127seconds/(semi-circle)2 h=b3-128…+127seconds/(semi-circle)3 AAAA,aaaa,d,t,w,andW=UTCData(seeICD-GPS-200,Table20-IXforscalefactors) AAAA=A0-2,147,483,648…+2,147,483,647seconds aaaa=A1-8,388,608…+8,388,607seconds/second d=DtLS-128…+127seconds t=tot0…602,112seconds w=WNt0…255weeks W=WNLSF0…255weeks n=DN1…7days D=DtLSF-128…+127seconds C=checksum Messagelength:29bytes


(Tx)@@Bp 00(Rx)@@Co 0EFEFF0239F1000F00000003000000080E0F7E4B070E

WinOnCore – Additional Message Window———————————————————————————@@Bp (Request UTC/Ionospheric Data) command...———————————————————————————UTC/Ionospheric Data Alpha0: 14 Alpha1: 254 Alpha2: 255 Alpha3: 2 Beta0: 57 Beta1: 241 Beta2: 0 Beta3: 15 A0: 3 A1: 8 DeltaT Leap Second: 14 tot: 15 WNt: 126 WNlsf: 75 DN: 7 DeltaTlsf: 14




6.2.1.3.15 Reset to Defaults (@@Cf)ThiscommandsetsalloftheGPSreceiverparameterstotheirdefaultvalues.Performanceofthisutilityresultsinallcontinuousmessagesbeingresettopollonlyoutput,andclearsthealmanacandephemerisdata.Thetimeanddatestoredintheinternalreal-timeclockarenotchangedbytheexecutionofthiscommand.

SettheGPSreceivertoDefault values:@@CfC<CR><LF>

where: C=0x25


Responsetoabovecommand:@@CfC<CR><LF>

where:

C=checksum



(Tx)@@Cf

(Rx)@@Cf


———————————————————————————

@@Cf (Set-to-Defaults) command...

———————————————————————————

Set-to-Defaults

Receiver Defaulted




6.2.1.3.16 Receiver ID (@@Cj)TheCW12outputsanIDmessageuponrequest.TheinformationcontainedintheIDstringisself-explanatory.Themodelnumbercanbeusedtodeterminethetypeofreceiverinstalled.ForaneasydropinreplacementweareusingamodelnumberthatisspecifictoMotorolaM12+device.Thisisveryusefulbecausetherewouldbenoupdatenecessaryforany“inhouse”developedsoftwarethatusesthereceiver’spartnumber.ForthecurrentimplementationtheCW12reportsthefollowingmodelnumber:

MODEL # P283T12T11 EQV

AlsothereisnodataforSerialNumber,ManufacturingDateorOptionsListavailable.

QueryReceiverID:@@CjC<CR><LF>

where:

C=checksum


Theresponseisoutputasa25columnby12rowarray.Generalformatisasshownbelow:

Figure 6 Receiver ID Binary Response Message Format




6.2.1.3.16 Receiver ID (@@Cj) continued


(Tx)@@Cj

(Rx)@@Cj 0D0A434F5059524947485420313939312D32303036204E415653594E43204C54442E20000A5346545720502F4E202 32302D4D4F5420202020202020000A534F46545741524520564552202320312E373920202020202020000A534 F4654574152452052455620232030352E30312E3030712020000A534F46545741524520444154452020446563203133 23036000A4D4F44454C202320202020503238335431325431312045515620000A4844575220502F4E202320435731322 D54494D20202020202020000A53455249414C20232020203C3C534E3E3E202020202020202020000A4D414E5546414354555220444154452058585858585858585858000A4F5054494F4E53204C4953542020202058585858585858585858


———————————————————————————

@@Cj (Receiver ID) command...

———————————————————————————

Receiver ID

COPYRIGHT 1991-2006 NAVSYNC LTD. SFTW P/N # NS20-MOT SOFTWARE VER # 1.79 SOFTWARE REV # 05.01.00q SOFTWARE DATE Dec 13 2006 MODEL # P283T12T11 EQV HDWR P/N # CW12-TIM SERIAL # <<SN>> MANUFACTURE DATE XXXXXXXXXX OPTIONS LIST XXXXXXXXXX

6.2.1.3.17 ASCII Position (@@Eq)TheASCIIpositionoutputmessagecontainsposition,timeandreceiverstatusinformationsimilarinscopetothe@@HbbinaryShortPositionmessage.TheASCIImessagemaybeamoreconvenientinterfaceforcertainapplicationswheretheASCIIoutputofNMEAisdesired.TheunitsandstyleofthedataissimilartoNMEAoutput.AsopposedtotheMotorlaM12GPSreceiver,theCW12doesnotsupportDGPS(DifferentialGPS)functionalityhencethefieldsthatarereferringtothistypeofinformationareleftblank(filledwith“0”).

Defaultmode:Polled

RequestASCIIPositionMessage:@@EqmC<CR><LF>

where:

m=outputmode0x00=outputresponsemessageonce(polled)

0x00..0xFF=responsemessageoutputatindicatedrate(continuous)

1(0x01)=oncepersecond

2(0x02)=onceeverytwoseconds

255(0xFF)=onceevery255seconds

C=checksum





6.2.1.3.17 ASCII Position (@@Eq) continuedResponsetoabovecommand:

@@Eq,mm,dd,yy,hh,mm,ss,dd,mm.mmmm,n,ddd,mm.mmmm,w,shhhh.h,sss.s,h,m,t,dd.d,nn,rrrr,aa,CC<CR><LF> where: Date: mm=minutes00..59 ss=seconds00..60 UTCTime: hh=hours0..23 mm=minutes00..59 ss-seconds00..60 Latitude: dd=degrees00..90 mm.mmmm=minutes00..59.9999 n=directionN=North,S=South Longitude ddd=degrees000..180 mm.mmmm=minutes00..59.9999 w=directionW=West,E=East Height: s=signofheight+or- hhhh.h=heightinmeters-1000.0..18,000.0 Velocity: sss.s=speedinknots000.0..999.9 hhh.h=headingindegrees000.0..359.9 Receiverstatus: m=fixmode 0=autonomous 1=differential t=fixtype 0=nofix 1=2Dfix 2=3Dfix 3=PositionPropagateMode dd.d=dilutionofprecision00.0…99.9,HDOPif2D,PDOPif3D nn=numberofsatellitesinuse00..32 rrrr=referencestationID0000..1023 aa=ageofdifferentialdatains00..60 CCC=checksum000..255 Messagelength:96bytes


(Tx)@@Eq 00

(Rx)@@Eq 1322C31352C30362C31322C34342C30362C35322C34322E333837302C4E2C3030382C34322E333837302C572 C2B30303036332E362C3030302E332C3132372E322C302C322C31332E372C31312C303030302C30302C3031


———————————————————————————

@@Eq (ASCII Position Message) command...

———————————————————————————

ASCII Position Message

,12,15,06,12,44,06,52,42.3870,N,008,42.3870,W,+00063.6,000.3,127.2,0,2,13.7,11,0000,00,01




6.2.1.3.18 Combined Position Message (@@Ga)Thismessageallowstheusertoenteraninitialpositionestimate.Ifthereceiveriscomputinga2Dfix,thereceiverwillignoreanyattemptstochangethelatitudeand/orlongitudeusingthiscommand.Ifthereceiveriscomputinga3Dfix,itwillalsoignoreanyattemptstochangeheightwiththiscommand.Undertheseconditionsthereceiverwillrespondwithcoordinatesofitscurrentlycalculatedlocation. Iftheuserinputsthe@@GaCombinedPositionmessagealongwiththe@@GbCombinedTimeand@@CbAlmanacInputmessagestoadefaultedreceiver,thereceiverwillbeina‘WarmStart’condition,resultinginarapidTTFF.Thisprocedureshouldbeusedwithcare.Ifanyofthedataiserroneous,theTTFFtimemayactuallybeextendedinsteadofshortened.DefaultValues: Latitude=0º Longitude=0º Height=0m(GPSHeight)

ChangeCurrentPositionCommand:@@GaaaaaoooohhhhtC<CR>LF> where: aaaa=latitudeinmas-324,000,000..+324,000,000(-90ºto+90º) oooo=longitudeinmas-648,000,000..+648,000,000(-180ºto+180º) hhhh=height-100,000..1,800,000cm(-1000to18000m) t=heighttype0=GPS,1=MSL(always0withM12+receivers) C=checksum MessageLength:20bytes

Responsetoabovecommand:@@GaaaaaoooohhhhtC<CR>LF> where: aaaa=latitudeinmas-324,000,000..+324,000,000(-90ºto+90º) oooo=longitudeinmas-648,000,000..+648,000,000(-180ºto+180º) hhhh=height-100,000..1,800,000cm(-1000to18000m) t=heighttype0=GPS,1=MSL(always0withM12+receivers) C=checksum MessageLength:20bytes


(Tx)@@Ga FFFFFFFFFFFFFFFFFFFFFFFFFF(Rx)@@Ga 0B4F4141FE176FBF00001BF300

WinOnCore – Additional Message Window———————————————————————————@@Ga(CombinedPositionMessage)command...———————————————————————————Combined Position Message Latitude: 52.706492 degrees Longitude: -8.894024 degrees Height: 71.550000 m Type: 0 (0 - GPS , 1 - MSL)

Tryingtochangethelatitudeandheightgivesthefollowingresult:


(Tx)@@Ga FF4F4141FE176FBF000186A000(Rx)@@Ga 0B4F409CFE1770F10000180600

WinOnCore – Additional Message Window———————————————————————————@@Ga (Combined Position Message) command...———————————————————————————Combined Position Message Latitude: 52.706446 degrees Longitude: -8.893939 degrees

Height: 61.500000 m Type: 0 (0 - GPS , 1 - MSL)




6.2.1.3.19 Combined Time Message (@@Gb)Thismessageallowstheusertogivethereceiveraninitialestimateofthecurrenttimeanddate.Ifthereceiverhasgoodtimesynchronization(i.e.nomillisecondambiguitybetweenthecodemeasurementsandthelocalTOW),itwillignoreanyattemptstochangethetimeanddateparametersusingthiscommand.Rather,thereceiverwillrespondwithcurrentlycalculatedtimeanddate.

Iftheuserinputsthe@@GbCombinedTime,@@GaCombinedPosition,and@@CbAlmanacInputmessagetoadefaultedreceiver,thereceiverwillbeina‘WarmStart’condition,resultinginarapidTTFF.Thisprocedureshouldbeusedwithcare.Ifanyofthedataiserroneous,theTTFFtimemayactuallybeextendedinsteadofshortened.

DefaultValues:Latitude=0º Longitude=0º Height=0m(GPSHeight)ChangeCurrentTimeMessage:@@GbmdyyhmsshmC<CR>LF> where: Date: m=month1…12 d=day1…31 yy=year1982…2100 Time: h=hours0…23 m=minutes0…59 s=seconds0…59 s=signedbyteofGMToffset00=positive255=negative h=hourofGMToffset0…+23 m=minutesofGMToffset0…59 C=checksum MessageLength:17bytes

Responsetoabovecommand:@@GbmdyyhmsshmC<CR>LF> where: Date: m=month1…12 d=day1…31 yy=year1982…2100 Time: h=hours0…23 m=minutes0…59 s=seconds0…59 s=signedbyteofGMToffset00=positive 255=negative h=hourofGMToffset0…+23 m=minutesofGMToffset0…59 C=checksum MessageLength:17bytes

Wehave3Dfixwehaveavailabledataandtime


(Tx)@@Gb 0FFFFFFFFFFFFFFFFFFF (Rx)@@Gb 040D07D60B1117000000 (Tx)@@Gb 0040D07D60B111700000 (Rx)@@Gb 040D07D60B1218000000

WinOnCore – Additional Message Window———————————————————————————@@Gb (Combined Time Message) command...———————————————————————————Combined Time Message Date: 04/13/2006 Time: 11:17:23 GMT Offset: 00h 00:00 (00h - Positive, FFh - Negative)



6. Communications Protocols continued 6.2.1.3.19 Combined Time Message (@@Gb) continued

———————————————————————————@@Gb (Combined Time Message) command...———————————————————————————Combined Time Message Date: 04/13/2006 Time: 11:18:24 GMT Offset: 00h 00:00 (00h - Positive, FFh - Negative)

6.2.1.3.20 1PPS Control Message (@@Gc)Thismessageallowstheusertochoosehowthe1PPSoutputfromthereceiverwillbehave.Defaultmode:Continuous

Change1PPSControl Command:@@GcpC<CR>LF> where: p=1PPScontrol0x00=1PPSdisabled 0x01=1PPSoncontinuously 0x02=1PPSactiveonlywhentrackingatleastonesatellite 0x03=1PPSonwhenT-RAIMconditionsaremet C=checksum MessageLength:8bytes

Responsetoabovecommand:@@GcpC<CR>LF> where: p=1PPScontrol0x00=1PPSdisabled 0x01=1PPSoncontinuously 0x02=pulseactiveonlywhentrackingatleastonesatellite 0x03=1PPSonwhenT-RAIMconditionsaremet C=checksum MessageLength:8bytes


(Tx)@@Gc 0F(Rx)@@Gc 02(Tx)@@Gc 00(Rx)@@Gc 00

WinOnCore – Additional Message Window———————————————————————————@@Gc (1PPS Control) command...———————————————————————————1PPS Control 1PPS Control: 2 (0 - 1PPS disabled, 1 - 1PPS on continuously, 2 - Pulse active only when tracking at least one satellite)———————————————————————————@@Gc (1PPS Control) command...———————————————————————————1PPS Control 1PPS Control: 0 (0 - 1PPS disabled, 1 - 1PPS on continuously,

2 - Pulse active only when tracking at least one satellite)




6.2.1.3.21 Position Control Message (@@Gd)Thismessageallowstheusertochooseinwhichpositioningmodethereceiverwilloperate.

Defaultmode:Continuous

ChangeCurrentPositionControlMode Message:@@GdcC<CR>LF>

where: c=controltype 0x00=enablenormal3Dpositioning 0x01=enablepositionhold 0x02=enable2Dpositioning(positioning receivers only) 0x03=enableauto-survey(timing receivers only)

C=checksum

MessageLength:8bytes

Responsetoabovecommand:@@GdpC<CR>LF>

where: c=controltype 0x00=enablenormal3Dpositioning 0x01=enablepositionhold 0x02=enable2Dpositioning(positioning receivers only) 0x03=enableauto-survey(timing receivers only)

C=checksum



(Tx)@@Gd FF

(Rx)@@Gd 00

(Tx)@@Gd 01

(Rx)@@Gd 01


———————————————————————————

@@Gd (Position Control Message) command...

———————————————————————————

Position Control Message

Control Type: 1

(0 - No hold or normal positioning,

1 - Enable Position Hold,

2 - Enable Altitude Hold)

———————————————————————————

@@Gd (Position Control Message) command...

———————————————————————————

Position Control Message

Control Type: 3

(0 - No hold or normal positioning,

1 - Enable Position Hold,

2 - Enable Altitude Hold)




6.2.1.3.22 T-RAIM Select Message (@@Ge)ThismessageallowstheusertoenableordisabletheTimeRAIMalgorithm.

Default:T-RAIMoff.

QueryCurrent TimeRAIMMode@@GexC<CR><LF>

where: x=onehexbyte:0xFF

C=0xDD


ChangeCurrentTimeRAIMMode@@GetC<CR><LF>

where: t=mode0x00=disable 0x01=enable

C=checksum


Responsetoeithercommand:@@GetC<CR><LF>

where: t=mode0x00=disable 0x01=enable

C=checksum



(Tx)@@Ge FF

(Rx)@@Ge 01


———————————————————————————

@@Ge (Time RAIM Enable Message) command...

———————————————————————————

Time RAIM Enable Message

TRAIM Algorithm: 1

(0 - Disabled, 1 - Enabled)




6.2.1.3.23 T-RAIM Alarm Message (@@Gf)ThismessageallowstheusertoentertheTimeRAIMalarmlimitinmultiplesof100ns,ortoquerythereceiverforthecurrentsetting.Thedefaultalarmlimitis1000ns.

Defaultvalue:1000ns

QuerycurrentT-RAIMAlarmSetting:@@GfxxC<CR><LF>

where:

xx=twohexbytes:0xFF0xFF

C=0x21


ChangeT-RAIMAlarmMessage:@@GfaaC<CR><LF>

where:

aa=T-RAIMalarmlimit(3–10,000in100sofnanoseconds)

C=checksum


Responsetoeithercommand:@@GfaaC<CR><LF>

where:

aa=T-RAIMalarmlimit(3–10,000in100sofnanoseonds)

C=Checksum



(Tx)@@Gf FFFF (query)

(Rx)@@Gf 000A

(Tx)@@Gf 000F (change)

(Rx)@@Gf 000F


———————————————————————————

Time RAIM Alarm Message

TRAIM Alarm: 1000 nsec

———————————————————————————

@@Gf (Time RAIM Alarm Message) command...

———————————————————————————

Time RAIM Alarm Message

TRAIM Alarm: 1500 nsec




6.2.1.3.24 Leap Second Pending Message (@@Gj)ThiscommandpollsthereceiverforleapsecondstatusinformationdecodedfromtheNavigationDatamessage.Theoutputresponseprovidesspecificdateandtimeinformationpertainingtoanyfutureleapsecondadditionorsubtraction.Presentandfutureleapsecondvaluesarealsooutputroundedtothenearestintegervalue.

Thiscommandonlyoperatesinapolledmanner,thusitmustberequestedeachtimeleapsecondinformationisdesired.

The‘presentleapsecondvalue’and‘futureleapsecondvalue’arereportedfromthenavigationdatafromthesatellites.Theydonotchangebasedontheleapsecondapplicationtime;theywillbeupdatedbasedonwhenthenavigationdataisupdated.

LeapsecondsareoccasionallyinsertedinUTCandgenerallyoccuronmidnightUTCJune30ormidnightUTCDecember31.TheGPScontrolsegmenttypicallynotifiesGPSusersofpendingleapsecondinsertionstoUTCseveralweeksbeforetheevent.Whenaleapsecondisinserted,thetimeofdaywillshowavalueof60intheseconds’field.Whenaleapsecondisremoved,thedatewillrolloverat58seconds.

The‘currentUTCoffset’willbezeroifUTCisdisabled.

QueryCurrentLeapSecondPendingStatus:@@GjC<CR><LF>

where: C=0x2D


Responsetoabovecommand:@@GjpfyymdiffffhmsC<CR>LF>

where: p=presentleapsecondvalue f=futureleapsecondvalue yy=yearofthefutureleapsecondapplication m=monthofthefutureleapsecondapplication d=dayofthefutureleapsecondapplication I=integerpartofcurrentUTCoffset(seconds) ffff=fractionalpartofcurrentUTCoffset(nanoseconds) h=houroftheleapsecondapplication0…23 m=minuteoftheleapsecondapplication0…59 s=secondoftheleapsecondapplication0…60

C=checksum



(Tx)@@Gj

(Rx)@@Gj 0E0E07D601010E00000000000000


———————————————————————————

@@Gj (Leap Second Status) command...

———————————————————————————

Leap Second Status

Present Leap Second: 14

Future Leap Second: 14

Date of Future Leap Second (YY/M/D): 2006/01/01

UTC Offset: 14.000000000 s

Time of Leap Second Application: 00:00:00




6.2.1.3.25 Vehicle ID (@@Gk)ThismessagesetsordefaultstheIDtag.Bydefault,theIDTagisthe6characterserialnumberofthereceiver.TheusermaychangetheIDtagtoanycombinationofsixASCIIcharactersbetween0x20(space)to0x7E(tilde)thatmayaidinidentificationofanumberofremotesitesorvehicles.Notethatspacecharacters(0x20)mayonlybeusedasfillersattheendoftheIDtag.

AnyoutofrangecharacterwillalsocausetheIDtagtoremainunchanged.AnIDtagmodifiedbytheuserwillonlyberememberedthroughpowercyclesifbatteryback-upisprovided.TheIDtagisalsooutputinthe12-channelPosition/Status/DataMessage(@@Ha)statusmessage.

ChangeCurrentVehicleID:@@GkvvvvvvC<CR><LF>

where: vvvvvv=6ASCII‘+’characters:’0x2B’=reverttoreceiverserialnumber or vvvvvv=6ASCIIcharacters:‘0x20’to‘0x7E’toinputuserdefinedID

C=checksum


Responsetoabovecommand:@@GkvvvvvvC<CR>LF>

where: vvvvvv=Current6characterIDtag:‘0x20’to‘0x7E’

C=checksum



(Tx)@@Gk 2A2A2A2A2A2A

(Rx)@@Gk 2A2A2A2A2A2A


———————————————————————————

@@Gk (ID Tag) command...

———————————————————————————

ID Tag

Rx Serial Number: ******




6.2.1.3.26 Channel Position/Status/Data (@@Ha)ThismessageisthestandardCW12binaryposition/statusmessage.The@@Hamessageprovidespositionandchannelrelateddatatotheuserataspecifiedupdaterate.

Defaultmode:Polled

Request12ChannelPosition/Status/DataMessage:@@HarC<CR><LF>

where: r=OutputRate 0x00=outputresponsemessageonce(polled) 0x01..0xFF=responsemessageoutputatindicatedrate: 0x01=oncepersecond 0x02=onceeverytwoseconds 0xFF=onceevery255seconds

C=checksum


Responsetoabovecommand.@@HamdyyhmsffffaaaaoooohhhhmmmmaaaaoooohhhhmmmmVVvvhddttimsidd(repeat‘imsidd’seriesforremaining11channels)ssrrccooooTTushmvvvvvvC<CR><LF>

Date: m=month1..12 d=day1..31 yy=year1998..2079

Time: h=hours0..23 m=minutes00..59 s=seconds0..60 ffff=fractionalsecond0..999,999,999nanoseconds

Position(FilteredorUnfilteredfollowingFilterSelect) aaaa=latitudeinmas-324,000,000..324,000,000(-90º..+90º) oooo=longitudeinmas-648,000,000..648,000,000(-180º..+180º) hhhh=GPSheightincm-100,000..+1,800,000(-1000..+18,000m)* mmmmMSLheightincmalways0,000,000withM12+

Position(AlwaysUnfiltered) aaaa=latitudeinmas-324,000,000..324,000,000(-90º..+90º) oooo=longitudeinmas-648,000,000..648,000,000(-180º..+180º) hhhh=GPSheightincm-100,000..+1,800,000(-1000..+18,000m)* mmmm=MSLheightincmalways0,000,000withM12+

Speed/Heading VV=3Dspeedincm/s0…51400(0.0to514m/s) vv=2Dspeedincm/s0…51400(0.0to514m/s) hh=2Dheading0….3599tenthsofdegrees(0.0to359.9º)

Geometry dd=currentDOP0..999(0.0to99.9DOP)(PDOPfor3Dfix,HDOPfor2Dfix,)

SatelliteData n=numberofvisiblesatellites0..12 t=numberoftrackedsatellites0..12




6.2.1.3.26 Channel Position/Status/Data (@@Ha) continued

ChannelData i=SVID0…32 m=mode0…8 0=CodeSearch 1=CodeAcquire 2=AGCSet 3=FreqAcquire 4=BitSyncDetect 5=MessageSyncDetect 6=SatelliteTimeAvailable 7=EphemerisAcquire

8=AvailableforPosition

s=signalstrength0…255 I=IODE0…255 dd=channelstatus(16bits) (msb) Bit15:Reserved Bit14:Reserved Bit13:Reserved Bit12:Narrow-bandsearchmode(timingrxonly) Bit11:Channelusedfortimesolution Bit10:DifferentialCorrectionsAvailable Bit9:InvalidData Bit8:ParityError Bit7:Channelusedforpositionfix Bit6:SatelliteMomentumAlertFlag Bit5:SatelliteAnti-SpoofFlagSet Bit4:SatelliteReportedUnhealthy Bits3-0:SatelliteAccuracyperpara20.3.3.3.1.3ofICD-GPS-200 0000(0)0.00m<URA<=2.40m 0001(1)2.40m<URA<=3.40m 0010(2)3.40m<URA<=4.85m 0011(3)4.85m<URA<=6.85m 0100(4)6.85m<URA<=9.65m 0101(5)9.65m<URA<=13.65m 0110(6)13.65m<URA<=24.00m 0111(7)24.00m<URA<=48.00m 1000(8)48.00m<URA<=96.00m 1001(9)96.00m<URA<=192.00m 1010(10)192.00m<URA<=384.00m 1011(11)384.00m<URA<=768.00m 1100(12)768.00m<URA<=1536.00m 1101(13)1536.00m<URA<=3072.00m 1110(14)3072.00m<URA<=6144.00m 1111(15)6144.00m<URA*

ss=receiverstatus

(msb)Bit15-13: 111=3DFix 110=2DFix 101=PropagateMode 100=PositionHold 011=AcquiringSatellites 010=BadGeometry 001=Reserved 000=Reserved





Channel Data continued

Bit12-11:Reserved Bit10:Narrowbandtrackingmode(timingrxonly) Bit9:FastAcquisitionPosition Bit8:FilterResetToRawGPSSolution Bit7:ColdStart(noalmanac,almanacoutofdateorhavealmanac buttimeorpositionunknown) Bit6:DifferentialFix Bit5:PositionLock Bit4:AutosurveyMode Bit3:InsufficientVisibleSatellites Bit2-1:AntennaSense 00=OK 01=OC 10=UC 11=NV Bit0:CodeLocation 0=EXTERNAL 1=INTERNAL

rrReserved

OscillatorandClockParameters: cc=clockbias-32768…32767ns oooo=oscillatoroffset0…250000Hz TT=oscillatortemperature-110…250halfdegreesC(-55.0…+125.0°C)

Timemode/UTCParameters: Bit7: 1=UTCtimemodeenabled 0=GPStimemodeenabled

Bit6: 1=UTCoffsetdecoded 0=UTCoffsetnotdecoded

Bits5-0:PresentUTCoffsetvalue,range–32…+31secondsfromGPStime*(ignoreifBit6=0).

GMTOffset: s=signedbyteofGMToffset0x00=positive0xFF=negative h=hourofGMToffset0…23 m=minuteofGMToffset0…59

vvvvvv=IDtag6characters(0x20to0x7e) C=checksum


ChannelDatacontinued






(Tx)@@Ha 00

(Rx)@@Ha

0C1207D60F0A0201406F400B4F4091FE1770A20000191F000000000B4F4091FE1770A20000191F000000000000000

00AE1000D0C0B10082DAF08A008082E8308A112082C5608A01B082C0A08A0130831C908A00308315408A00B082

D8B08A0150829AE08A01A08263E09A11608320508A21D00002D00201C08213608A1E000000093EFFFFFFBC9000

04E000000202020202020


———————————————————————————

@@Ha (Position/Status/Data Message (12 Channel)) command...

———————————————————————————

Position/Status/Data Message (12 Channel)

Date: 12/18/2006

Time: 15:10:02.021000000

Latitude: 52.706443

Longitude: -8.893961

GPS Height: 64.310000

MSL height: 0.000000

Latitude (Unfiltered): 52.706443

Longitude (Unfiltered): -8.893961

GPS Height (Unfiltered): 64.310000

MSL height (Unfiltered): 0.000000

3D Speed: 0.000000

2D Speed: 0.000000 2D Heading: 278.500000

DOP: 1.300000

Visible Satellites: 12

Tracked Satellites: 11

*Refer to the Signal Quality Window for satellite visibility and tracking status.

Receiver Status: 0000E000h

Clock Bias: 37871

Oscillator Offset: 4294966217

Temperature: 0.000000

UTC Parameters: 4Eh

GMT Offset: 00h 00:00 (00h - Positive, FFh - Negative)

ID Tag:




6.2.1.3.27 Short Position Message (@@Hb)Thisisashortenedversionofthe@@Hapositionmessageprovidedtotheuserataspecifiedupdaterate.

Defaultmode:Polled

RequestShortPositionMessage:@@HbrC<CR><LF>

where: r=outputrate 0=outputresponsemessageonce(polled) 1..255=responsemessageoutputatindicatedrate(continuous): 0x01=oncepersecond 0xFF=onceevery255seconds

C=checksum


Responsetoabovecommand.@@HbmdyyhmsffffaaaaoooohhhhmmmmVVvvhddntssrrvvvvvvC<CR><LF>

Date: m=month1..12 d=day1..31 yy=year1998..2079

Time: h=hours0..23 m=minutes00..59 s=seconds0..60 ffff=fractionalsecond0..999,999,999nanoseconds

Position(FilteredorUnfilteredfollowingFilterSelect) aaaa=latitudeinmas-324,000,000..324,000,000(-90º..+90º) oooo=longitudeinmas-648,000,000..648,000,000(-180º..+180º) hhhh=GPSheightincm-100,000..+1,800,000(-1000..+18,000m)* mmmmMSLheightincmalways0,000,000withM12+

Speed/Heading VV=3Dspeedincm/s0…51400(0.0to514m/s) vv=2Dspeedincm/s0…51400(0.0to514m/s) hh=2Dheading0….3599tenthsofdegrees(0.0to359.9º)

Geometry dd=currentDOP0..999(0.0to99.9DOP)(PDOPfor3Dfix,HDOPfor2Dfix,00.0otherwise)

SatelliteData n=numberofvisiblesatellites0…12 t=numberoftrackedsatellites0…12

ssreceiverstatus

(msb)Bits15-13: 111=3DFix 110=2DFix 101=PropagateMode 100=PositionHold 011=AcquiringSatellites 010=BadGeometry 001=Reserved 000=Reserved




6.2.1.3.27 Short Position Message (@@Hb) continuedBits12-11:Reserved

Bit10:Receiverinnarrow-bandtrackingmode

Bit9:FastAcquisitionPosition

Bit8:FilterResetToRawGPSSolution

Bit7:ColdStart(noalmanac,almanacoutofdateorhavealmanacbuttimeorpositionunknown)

Bit6:DifferentialFix

Bit5:PositionLock

Bit4:AutosurveyMode

Bit3:InsufficientVisibleSatellites

Bits2-1:AntennaSense00=OK

01=Overcurrent

10=Undercurrent

11=Nobiasvoltage

Bit0:CodeLocation0=EXTERNAL

1=INTERNAL

rrReserved

vvvvvv=IDtag6characters(0x20to0x7e)

C=checksum



(Tx)@@Hb 00

(Rx)@@Hb 0C1207D611051C01AB3F000B4F40F5FE1770B8000017AA0000000000000000003B00140A08E00

00000202020202020


———————————————————————————

@@Hb(ShortPositionData)command...

———————————————————————————

ShortPositionData

Date:12/18/2006

Time:17:05:28.028000000

Latitude:52.706471

Longitude:-8.893955

GPSHeight:60.580000

MSLHeight:0.000000

3DSpeed:0.000000

2DSpeed:0.000000

2DHeading:5.900000

DOP:2.000000

VisibleSatellites:10

TrackedSatellites:8

ReceiverStatus:E000h

IDTag:




6.2.1.3.28 Channel Time RAIM Status Message (@@Hn)ThismessageallowstheusertorequestoutputofT-RAIMstatusinformation.

WhentheT-RAIMalgorithmisenabledwiththe@@Ge01command,theCW12basesthereportedT-RAIMStatusandSolutioninthe@@Hncommandfromthenumberofsatellitestrackedandthe1-sigmatimingaccuracyestimate(TACC).TheCW12iscapableofremovingfaultysatellitesfromthesolutionifthenumberofsatellitesinthesolutionis5ormore.SotheT-RAIMStatusis0(detectionandisolationpossible)whenthenumberofvisiblesatellitesis5ormore.Thereceivercancontinuetodetectfaultysatelliteswhilethenumberofvisiblesatellitesis3ormore.Sowhenthenumberofvisiblesatellitesis3,4,or5,theT-RAIMStatusis1(detectiononlypossible).Finallyifnumberofvisiblesatellitesis2orfewer,theT-RAIMStatusis2(neitherpossible).

WhentheT-RAIMStatusis0or1,theT-RAIMSolutionisdeterminedbyacomparisonofthe1-sigmatimingerrorestimateandtheAlarmThresholdsetwiththe@@Gfcommand.WhentheT-RAIMStatusis2,theT-RAIMSolutionis2(unknown).TheT-RAIMSolutionis0(OK)whentheAlarmThresholdislessthanfourtimestheonesigmaAccuracyestimate.FourtimestheonesigmaAccuracyestimatewaschosenbecausea+/-4-sigmaconfidenceintervalisequivalenttothe99.99%detectionandisolationprobabilityoftheT-RAIMalgorithmintheCW12.

Thisisforanormaldistribution,whichisavalidassumptionfortheGPStimingerrors.

RequestCurrentTimeRAIMStatus:@@HnrC<CR><LF>

where: r=outputrate 0=polledonce 1..255=outputatindicatedrate: 0x01=oncepersecond 0x02=onceperevery2seconds 0xFF=onceper255seconds

C=checksum


Responsetoabovecommand:@@Hnpysrvvvveensffff(repeatsffffforremaining11channels)C<CR><LF>

where: p=pulsestatus0=off 1=on

y=1PPSpulsesync 0=pulsereferencedtoUTC, 1=pulsereferencedtoGPStime

s=TimeRAIMSolution 0=solutionwithinalarmlimits; 1=ALARM,user-specifiedlimitexceeded 2=UNKNOWN,dueto: a.alarmthresholdsettoolow b.T-RAIMturnedoff c.insufficienttrackedsatellites

r=TimeRAIMstatus 0=detectionandisolationpossible; 1=detectiononlypossible; 2=neitherpossible

vvvv=32bitfieldtoindicatewhichsvidswereremovedbyT-RAIM

ee=timesolutiononesigmaaccuracy0..65535nsecestimate

n=negativesawtoothtimeerror–128..+127nsofnextpulse

Foreachof12channels: s=satelliteid1..32 ffff=fractionalGPSlocaltime0..999999999nsestimateofsatellite

C=checksum





6.2.1.3.28 Channel Time RAIM Status Message (@@Hn) continuedWinOnCore – Command Monitor Window

(Tx)@@Hn 00

(Rx)@@Hn 0100000000000000001A0019012D0E8715012D0E740A012D0E8203012D0E870D0

12D0E8317012D0E8A07012D0E8F06012D0E8B000000000010012D0E7800000000001F012D0E85


———————————————————————————

@@Hn (12-Channel Time RAIM Status Message) command...

———————————————————————————

12-Channel Time RAIM Status Message

pulse status 1

pulse sync 0

solution status 0

traim status 0

svids removed 0000h

sigma accuracy 26

sawtooth error 0

Ch SVID Fractional Time Estimate (ns)

01 25 19730055

02 21 19730036

03 10 19730050

04 3 19730055

05 13 19730051

06 23 19730058

07 7 19730063

08 6 19730059

09 0 0

10 16 19730040

11 0 0

12 31 19730053




6.2.1.3.29 12 Channel Self-Test Message (@@Ia)TheCW12receiveruserhastheabilitytoperformanextensiveself-test.TheteststhatareaccomplishedduringtheSelf-Testareasfollows:

• Antenna connection• RTC communication and time• Temperature sensor• RAM• FLASH ROM• Correlator IC

Theoutputoftheself-testcommandisa24-bitfield,whereeachbitofthefieldrepresentsthePass/Failconditionforeachparametertested.Passedtestsareindicatedbyalogic‘1’,whilefailedtestsareindicatedbyalogic‘0’.

Whentheself-testisinitiated,thenextoutputmessagemaynotbetheresponse.Theself-testmaytakeuptotensecondstoexecute.Oncetheself-testiscomplete,thesatelliteacquisitionprocessrestartsaswhenthereceiverwasfirstpoweredon.Thedate,time,position,almanacandephemerisinformationisallretained.TheCW12hasverylimitedsupportforthiscommand;howeverthebitdescriptionsforthereplymessagehavebeenkeptinordertopreservetheconsistencywiththeMotorolaM12usermanual.

Responsetoabovecommand:@@IasssC<CR>LF>

where: sss=selftestresults (msb) Bits23-22:AntennaSense(currentlynotsupported–workinprogress) 00=OK 01=Overcurrent 10=Undercurrent 11=Nobiasvoltagepresent Bit21:RTCcomm&time(notsupported) Bit20:TemperatureSensor(notsupported) Bit19:spare Bit18:RAM(notsupported) Bit17:ROM Bit16:1KHzpresence(notsupported) Bit15:spare Bit14:TemperatureSensor(notsupported) DataChecksum Bit13:OscillatorDataChecksum(notsupported) Bit12:ManufacturingDataChecksum(notsupported) Bit11:Channel12correlatortest(notsupported) Bit10:Channel11correlatortest(notsupported) Bit9:Channel10correlatortest(notsupported) Bit8:Channel9correlatortest(notsupported) Bit7:Channel8correlatortest(notsupported) Bit6:Channel7correlatortest(notsupported) Bit5:Channel6correlatortest(notsupported) Bit4:Channel5correlatortest(notsupported) Bit3:Channel4correlatortest(notsupported) Bit2:Channel3correlatortest(notsupported) Bit1:Channel2correlatortest(notsupported) Bit0:Channel1correlatortest(notsupported)

C=checksum





6.2.1.3.29 12 Channel Self-Test Message (@@Ia) continuedWinOnCore – Command Monitor Window

(Tx)@@Ia

(Rx)@@Ia 377FFF


———————————————————————————

@@Ia(Self-TestMessage(12Channel))command...

———————————————————————————

Self-Test Message (12 Channel)

Self Test Byte 1: 37h

Self Test Byte 2: 7Fh

Self Test Byte 3: FFh

6.2.1.3.30 System Power-On Failure (@@Sz)Immediatelyafterpower-up,theCW12’sROMistested.Ifthistestdoesnotpass,thefirmwarewillnotexecute

itspositioningalgorithms.Rather,itwillcontinuouslyoutputthismessageonceevery10seconds.Receiptof

thismessageindicatesthatthereceiverwillneedtoberepairedand/orreprogrammed.Thisfeaturekeepsthe

receiverfrombeingutilizedwhentheROMhasbeencompromised,andthereforeunreliable,helpingtoprotect

theintegrityoftheapplication.

@@SzcC<CR><LF>

where:

c=constantequalto0

C=checksum





6.2.2 NMEA MessagesTherearetwomaintypesofsentences,‘Approved’and‘Proprietary’.Allsentencesstartwith$delimitedwithcommasandend-ingwith<CR><LF>.Approvedsentencesarerecognizedbythefirst5charactersafterthe$,whichdefineboththekindoftalkerprovidingtheinformation(2characters,GPinthecaseofaGPS),andthetypeofinformation(3characters).Proprietarysen-tencesareindicatedbyaPfollowingthe$,asthefirstofthe5characters,thenext3indicatingthemanufacturer(fromalistingofmnemoniccodes),andthe5thcharacterbeingselectedbythatmanufacturerfortheparticularsentencestructure.Propri-etarysentencesmustconformwiththegeneralNMEAstructures,butareotherwiseundefinedoutsideoftheManufacturersowndocumentation.

ThefollowingApprovedmessagesareavailablefromtheCW12receiver:GPGLL-GeographicPosition-LatitudeandLongitudeGPGGA-GlobalPositioningSystemFixDataGPGSA-GNSSDOPandActiveSatellitesGPGSV-GNSSSatellitesinViewGPRMC–Minimumrequiredsentence

Thefollowingproprietarymessagesaredisabledfromthestandardbuildbutcanbemadeavailablelateronforspecialbuilds:POLYA–GPGGAwithadditionalestimatedaccuracyPOLYP–NavSyncproprietarystatusmessagePOLYS–NavSyncProprietarysatellitestatusmessage(GPGGA+GPGSV)POLYI-NavSyncProprietarynetassistinformationmessage

6.2.2.1 GLL, Geographic position, Lat/Lon.Latitudeandlongitude,withtimeofpositionfixandstatus.$GPGGL, Latitude , N ,Longitude , hhmmss.ss,Status*cs

Name Description$GPGGA NMEAsentenceheader(PositionData)Latitude Userdatumlatitudedegrees,minutes,decimalminutesformat(ddmm.mmmmm)N Hemisphere‘N’=North,or‘S’=SouthLongitude Userdatumlongitudedegrees,minutes,decimalminutesformat(dddmm.mmmmm)E LongitudeDirection‘E’=East,or‘W’=Westhhmmss.ss UTCTimeinhours,minutes,seconds.anddecimalsecondsformat.Status StatusV=navigationreceiverwarning,A=datavalidcs Messagechecksuminhexadecimal




6.2.2.2 GGA, GPS fix dataTimeandposition,togetherwithGPSfixingrelateddata(numberofsatellitesinuse,andtheresultingHDOP,ageofdifferentialdataifinuse,etc.).$GPGGA, hhmmss.ss , Latitude , N ,Longitude , E , FS , NoSV , HDOP , Altref , m , msl , m, DiffAge , DiffStation*cs

Name Description$GPGGA NMEAsentenceheader(PositionData)hhmmss.ss UTCTimeinhours,minutes,seconds.anddecimalsecondsformat.Latitude Userdatumlatitudedegrees,minutes,decimalminutesformat(ddmm.mmmmm)N/S Hemisphere‘N’=North,or‘S’=SouthLongitude Userdatumlongitudedegrees,minutes,decimalminutesformat(dddmm.mmmmm)E LongitudeDirection‘E’=East,or‘W’=WestFS FixStatus:0Nofix1StandardGPS2DifferentialGPSNoSV NumberofsatellitesusedinthepositionsolutionHDOP 2-DHorizontalDilutionofPrecision(00.0to99.9)Altmsl Antennaaltitudeabove/belowmeansealevel(WGS84geoid)M Unitsofheight(meters)MSLcorr Geoidalseparation,userdatummeansealevelcorrection(Diff.betweenWGS-84earth ellipsoidandmeansealevel.“-”signmeansthatgeoidisbelowWGS-84ellipsoid)m Unitsofheight(meters)DiffAge AgeofdifferentialcorrectionDiffStation DifferentialbasestationIDcs Messagechecksuminhexadecimal

6.2.2.3 GSA, GPS DOP and Active satellitesGPSreceiveroperatingmode,satellitesusedfornavigation,andDOPvalues.

$GPGSA,Smode,FS,sv,sv,sv,sv,,,,,,,,PDOP,HDOP,VDOP*cs

Name Description$GPGSA NMEAsentenceheader(SatelliteData)Smode A=Automaticswitching2D/3DM=Manuallyfixed2D/3D)FS FixStatus: 0Nofix 1StandardGPS 2DifferentialGPSsv Satellitesinuse,nullforunusedfieldsHDOP 2-DHorizontalDilutionofPrecision(00.0to99.9)VDOP VerticalDilutionofPrecision(00.0to99.9).PDOP 3-DPositionDilutionofPrecision(00.0to99.9)cs Messagechecksuminhexadecimal




6.2.2.4 GSV, GPS Satellites in ViewThenumberofsatellitesinview,togetherwitheachPRN,elevationandazimuth,andC/Novalue.Onlyfoursatellitedetailsaretransmittedinonemessage,therebeinguptothreemessagesusedasindicatedinthefirstfield.

$GPGSV, NoMsg, MsgNo, NoSv,sv,elv,az,cno{,sv,elv,az,cno….}*cs

Name Description$GPGSV NMEAsentenceheader(SatelliteData)NoMsg TotalnumberofGPGSVmessagesbeingoutputMsgNo Numberofthismessagesv SatellitesIDelv Satelliteelevationangle(degrees)az Satelliteazimuthangle(degrees)cno Satellitesignal/Noiseration(dB/Hz)cs Messagechecksuminhexadecimal

Numberofmessages(maximum3)

6.2.2.5 RMC, Recommended Minimum dataThe‘RecommendedMinimum’sentencedefinedbyNMEAforGPS/Transitsystemdata.Theuseofachecksumfieldismandatory.

$GPRMC,hhmmss,status,latitude,N,longitude,W,spd,cmg,ddmmyy,mv,*cs

Name Description$GPRMC NMEAsentenceheader(RecommendedMinimumSentence)hhmmss UTCTimeinhours,minutes,seconds.status StatusV=navigationreceiverwarning,A=datavalidLatitude Userdatumlatitudedegrees,minutes,decimalminutesformat(ddmm.mmmmm)N Hemisphere‘N’=North,or‘S’=SouthLongitude Userdatumlongitudedegrees,minutes,decimalminutesformat(dddmm.mmmmm)E LongitudeDirection‘E’=East,or‘W’=Westspd Speedoverground(knots).cmg Coursemadegoodhhmmss DateinDay,MonthYearformatmv Magneticvariationcs Messagechecksuminhexadecimal




6.2.2.6 VTG, Course over ground and Ground speedVelocityisgivenasCourseOverGround(COG)andGroundSpeed

$GPVTG,cogt,T,cogm ,M ,knots,N,kph,K*cs

Name Description$GPVTG NMEAsentenceheader(Speedandheading)cogt Courseoverground(true)T True-fixedfieldcogm Courseoverground(magnetic)M Magnetic-fixedfieldknots Speedoverground(knots)N Knots-fixedfieldkph Speedoverground(kph)K kph–fixedfieldcs Messagechecksuminhexadecimal

6.2.2.7 POLYT, Time of Day$POLYT,hhmmss.ss,ddmmyy, UTC_TOW ,week, GPS_TOW ,Clk_B , Clk_D ,PG,cs

$POLYT,123456.00,250299,123456.00,0978,123456.00,123456,123.456,28,cs

Name Description$POLYT NavSyncProprietaryNMEAsentenceheader(PositionData)hhmmss.ss UTCTimeinhours,minutes,seconds.anddecimalsecondsformat.ddmmyy Dateinday,month,yearformat.UTC_TOW UTCTimeofWeek(seconds)week GPSweeknumber(continuesbeyond1023)GPS_TOW GPSTimeofWeek(seconds)Clk_B ReceiverclockBias(nanoseconds)Clk_D ReceiverclockDrift(nanoseconds/second)PG 1PPSGranularity(nanoseconds)cs Messagechecksuminhexadecimal




6.2.2.8 POLYP, Position Data$POLYP,hhmmss.ss, Latitude ,N, Longitude ,E, AltRef ,FS,Hacc,Vacc, SOG , COG , Vvel ,ageC,HDOP,VDOP,PDOP,TDOP,GU,RU,DR,cs

$POLYP,123456.00,5214.12345,N,00056.12345,W,00138.80,G3,0002,0002,021.21,180.00,+003.96,99.9,01.1,01.6,01.9,01.7,07,00,00,cs

Name Description$POLYP NavSyncProprietaryNMEAsentenceheader(PositionData)hhmmss.ss UTCTimeinhours,minutes,seconds.anddecimalsecondsformat.Latitude Userdatumlatitudedegrees,minutes,decimalminutesformat(ddmm.mmmmm)N Hemisphere‘N’=North,or‘S’=SouthLongitude Userdatumlongitudedegrees,minutes,decimalminutesformat(dddmm.mmmmm)E LongitudeDirection‘E’=East,or‘W’=WestAltRef Altitude(meters)aboveuserdatumellipsoid.FS FixStatus: NFNoFix DRPredictiveDeadReckoningsolution DAPredictiveDeadReckoningsolutionwithDRaiding G1PartialGPSsolutionwithDRaiding G2Standalone2Dsolution G3Standalone3Dsolution D1PartialDifferentialGPSsolutionwithDRaiding D2Differential2Dsolution D3Differential3DsolutionHacc Horizontal(2sigma)accuracyestimates.(0to9999meters)Vacc Vertical(2sigma)accuracyestimates.(0to9999meters)SOG SpeedOverGround(knots)(000.00to999.99knots)COG CourseOverGround(true)indegrees(000.00to359.99degrees)V_vel Vertical(positiveUp)velocity(m/s)(000.00to999.99m/s)ageC AgeofmostrecentDGPSCorrectionsapplied(seconds).(00.0to99.9=noneavailable)HDOP 2-DHorizontalDilutionofPrecision(00.0to99.9)VDOP VerticalDilutionofPrecision(00.0to99.9).PDOP 3-DPositionDilutionofPrecision(00.0to99.9)GDOP 4-DGeometricDilutionofPrecision(00.0to99.9)TDOP TimeDilutionofPrecision(00.0to99.9)GU NumberofGPSsatellitesusedinthenavigationsolutionRU NumberofGLONASSsatellitesusedinthenavigationsolutionDR DeadReckoningaidingstatusbits(inASCIIHex) bit0 AltitudePositionAidingapplied bit1 VerticalVelocityAidingapplied bit2 (GPS-GLONASS)timedifferenceaidingapplied bit3 ExternalDistancetravelledinputused bit4 ExternalSpeedinputused bit5 ExternalTrackinputused bit6 ExternalDelta-Trackinputused. bit7-8 Reservedforfutureuseecs Messagechecksuminhexadecimal




6.2.2.9 POLYU, UTM Position DataThis message is only available in enhanced software versions.

$POLYP,hhmmss.ss, Easting ,E, Northing ,N, AltMSL ,FS,Hacc,Vacc, SOG , COG , Vvel, ZageC, HDOP ,VDOP ,PDOP ,TDOP ,GU ,RU ,DR ,cs

$POLYP,123456.00,1234567.123,W,1234567.123,N,00138.80,G3,0002,0002,021.21,180.00,+003.96,99.9,01.1,01.6,01.9,01.7,07,00,00,cs

The$POLYUisaUTM(UniversalTransverseMercatorprojection)versionofthe$POLYPsentence.

6.2.2.10 POLYG, Local Grid Position DataThis message is only available in enhanced software versions.

$POLYP,hhmmss.ss, Easting ,E, Northing ,N, AltMSL ,FS,Hacc,Vacc, SOG , COG , Vvel ,ageC,HDOP,VDOP,PDOP,TDOP,GU,RU,DR,cs

$POLYP,123456.00,1234567.123,W,1234567.123,N,00138.80,G3,0002,0002,021.21,180.00,003.96,99.9,01.1,01.6,01.9,01.7,07,00,00,csThe$POLYGisthesameasthe$POLYUsentence,exceptthattheUTMpositionhasbeenshiftedtoaLocalGridpositionbyapplyingaEasting,NorthingandHeightoffsets.ThepositionoutputwillbeexactlythesameastheUTMpositioniftheLocalGridhasnotbeendefined.

6.2.2.11 POLYS, Satellite Status$POLYS,GT,ID,s,AZM,EL,SN,LK,ID,s,AZM,EL,SN,LK,ID,s,AZM,EL,SN,LK,ID,s,AZM,EL,SN,LK,ID,s,AZM,EL,SN,LK,...,cs

$POLYS,05,03,U,103,56,48,99,23,U,225,61,39,99,16,U,045,02,41,99,26,U,160,46,50,32,30,-,340,04,50,00,cs

Name Description$POLYS NavSyncProprietaryNMEAsentenceheader(SatelliteData)GT NumberofGPSsatellitestrackedID SatellitePRNnumber(1-32)s Satellitestatus - =notused U =usedinsolution e =availableforuse,butnoephemerisAZM Satelliteazimuthangle(range000-359degrees)EL Satelliteelevationangle(range00-90degrees)SN Signaltonoiseratioin(range0-55dBHz)LK Satellitecarrierlockcount(range0-255seconds) 0 =codelockonly 255 =lockfor255ormoresecondscs Messagechecksuminhexadecimal




6.2.2.12 POLYI, Additional Information Message

$POLYI,JN,jammer,EXT,efields,INT,ifields,cs $POLYI,JN,12,EXT,HPOS,VPOS,INT,CLKB

Name Description$POLYI NavSyncProprietaryNMEAsentenceheader(AdditionalInformation)JN Fixeddescriptorfieldjammer DetectedJammertoNoiseRatio[dBHz]EXT Fixeddescriptorfield,indicatestheuseofexternallyprovidedancillarymeasurementse.g. receivedfromNetworkAssistance.Allcommaseparatedefieldsfollowing,uptotheINT fielddescriptor,areexternallyprovidedmeasurementsefields DIFF =DifferentialInputs TSYNC =Timesynchronization CLKB =ClockBias FREQ =Frequency(ofreferenceoscillator) HPOS =Horizontalposition VPOS =VerticalPosition(altitude) VVEL =VerticalVelocity DIST =DistanceMoved SPEED =CurrentSpeed TRACK =Currenttrack DTRACK =Deltatrack(changeindirection)INT Fixeddescriptorfield,indicatestheuseofinternallyprovidedancillarymeasurementse.g. retrievedfromnonvolatilememory.Allcommaseparatedifieldsfollowing,uptotheINT fielddescriptor,areinternallyprovidedmeasurementsifieldsTSYNC =Timesynchronization CLKB =ClockBias FREQ =Frequency(ofreferenceoscillator) HPOS =Horizontalposition VPOS =VerticalPosition(altitude) VVEL =VerticalVelocity DIST =DistanceMoved SPEED =CurrentSpeed TRACK =Currenttrack DTRACK =Deltatrack(changeindirection)




6.2.3 Proprietary Commands

TheNavSyncCW12receiverhasauniquesetofproprietarycommands.Commands will only be accepted on UART 1, if NMEA protocol is enabled on this port (this option is available in en-hanced versions).Thecommandstoandfromtheunithavethefollowinggeneralformats:

$PRTH<Q|S|R>,<id>,<msgfields>[*<checksum>]<cr><lf>

Where:<S|Q|R>isthesingleASCIIcharacterasfollows:S:Command,requirestheCW12receivertoSetsystemsettings.Q:Command,aQuerycommandtotheCW12receiver.R:Response,anCW12receiverorResponsetoa$PRTHQueryoranacknowledgmentofa$PRTHSet.<id>isa4charactercommandidentifier.<msgfields>arethemessagefieldsforthemessageandareallpositional.Optionalorunknownfieldsareshownasnulls(ieadjacentcommas).Trailingcommastotheendofamessage(ienothingbutnullmessagefields)arenotrequired.*<checksum>Anoptionalchecksumbyteforcheckingaccuracydefinedasfollows:

ThechecksumisdisplayedasapairofASCIIcharacters,(0-9andA-Finclusive)whosevaluerepresentsthe“HEX”valueofthechecksumbyte.Whenused,italwaysappearsasthelastfieldofthesentenceandisprefixedbyfielddelimiter“*”(HEX2A)insteadof“,”andfollowedby<CR><LF>(HEX0D0A).ThechecksumvalueiscalculatedbyXOR’ing(exclusiveOR’ingalsoknownasModulo2Sum)the8binarydatabitsofeachvaliddatacharacterinthesentencebetweenthe“$”(HEX24)and“*”(HEX2A)characters.

The“$”(HEX24)andthe“*”(HEX2A)charactersarenotincludedinthechecksum.<cr><lf>aretheASCIIcodes0Dhand0Ah(carriagereturnandlinefeed)respectively.

Somecommandsusemultiplesentencestotransferdata:multiplesentencetransfershallbeaccomplishedbymeansof2fieldswithinthesentenceforwhichthisformatisused:t:Totalnumberofsentencesformingthedatatransfer(minimumvalue1)x:IDnumberofthecurrentsentencerangingfrom1totinclusive

Nullfieldswithinacommandshallbeinterpretedas“usecurrentvalue”whereappropriate.Nullfieldsmustbedelimitedbyadja-centcommaswhentheyexistbetweentwonon-nullfields.Ifalltrailingfieldsafteragivenfieldarenull,furthercommasarenotrequired.

6.2.3.1 PRTH<Q|S|R>,DRL M: DEAD RECKONING LIMITPurpose

ThismessageSets,QueriesandRespondstothelimitfortheforwardpredictiveDeadReckoning,afterthelastvalidfix(epochs).Thedeadreckoningwillprogressatconstantvelocityforthefirsthalfofthisperiodandthenreducetoastandstillduringthesecondhalf.

Query Format$PRTHQ,DRLM[*checksum]<cr><lf>

Set Format$PRTHS,DRLM,DR_Limit[*checksum]<cr><lf>

Response / Acknowledge Format$PRTHR,DRLM, DR_Limit*<checksum><cr><lf>

Explanation of ParametersDR_Limit Numberofepochstodeadreckonfor(integer,range0–32768)




6.2.3.2 PRTH<Q|S|R>,ILLH: INITIALIZED LAT, LONG, HEIGHT POSITIONPurpose

ThismessageSets,QueriesandRespondstotheinitializedgeodeticposition(latitude,longitude,ellipsoidalheightandantennaheightabovethereferencemarker)inthereceiver’scurrentuserdatum.ThepositionRMSaccuracyisusedtodecidehowmuchimportancetoputontheinputvaluesandshouldbesetwithcare.

Query Format$PRTHQ,ILLH[*checksum]<cr><lf>

Set Format$PRTHS,ILLH,LatDeg,LatMin,LatSec,LatH,LonDeg,LonMin,LonSec,LonH,EllHt,AntHt,posRMS[*checksum]<cr><lf>

Response / Acknowledge Format$PRTHR,ILLH,LatDeg,LatMin,LatSec,LatH,LonDeg,LonMin,LonSec,LonH,EllHt,AntHt,posRMS*<checksum><cr><lf>

Explanation of ParametersLatDeg Latitudedegrees(floatingpoint,range±90.0)LatMin Latitudeminutes(floatingpoint,range±59.999999)LatSec Latitudeseconds(floatingpoint,range±59.99999)LatH Latitudehemisphere(char‘N’or‘S’)LonDeg Longitudedegrees(floatingpoint,range±90.0)LonMin Longitudeminutes(floatingpoint,range±59.999999)LonSec Longitudeseconds(floatingpoint,range±59.99999)LonH Longitudehemisphere(char‘E’or‘W’)EllHt Heightofthereferencemarkerabovethecurrentuserdatumreferenceellipsoidinmeters (floatingpoint,range±18,000.0)AntHt Heightoftheantennaphasecenterabovethereferencemarkerheightdefinedby EllHt aboveinmeters (floatingpoint,range±18,000.0)posRMSRMSaccuracyoftheinputposition(meters)(floatingpoint,range0-999999.0)

NotethatsincetheDegree,MinutesandSecondsfieldswillacceptfloatingpointvaluesthenadecimaldegreevalue,orandintegerdegree,decimalminutevaluecanbeinputdirectlybysettingtheminutesandsecondsfieldstozeroasappropriate(eg52.12345678,0,0,Nor52,14.123456,0,N).

6.2.3.3 PRTH<Q|S|R>,ITIM: INITIALIZE TIME AND DATEPurpose

ThismessageSets,QueriesandRespondstotheuserinitializedtimeanddate.Twoinputoptionsareavailable,oneallowingacalendardateandGMTtimetobeinputandtheotheraGPSweeknumberandsecondsofweek. TheinputdateisacteduponregardlessandisprimarilyusedtosettheGPSweekinsidethereceiver.Thetimeinputwillnotbeusedifissettozero,orifthereceiveriscurrentlytrackinganysatellitesandthereforealreadyhasagoodsub-millisecondknowledgeoftime. IfthetimeinputisnotusedthentheResponsemessagereturnsthevaluesusedorassumedinsteadofthoseinput.ThetimeRMSaccuracyisusedtodecidehowmuchimportancetoputontheinputvaluesandshouldbesetwithcare.

Query Format$PRTHQ,ITIM[*checksum]<cr><lf>

Set FormatUsingaGMTtimeformat$PRTHS,ITIM,timeRMS,GMT,day,month,year,[hours],[minutes],[seconds][*checksum]<cr><lf>UsingaGPStimeformat$PRTHS,ITIM,timeRMS,GPS,gps_week,[gps_time][*checksum]<cr><lf>

Response / Acknowledge Format$PRTHR,ITIM,timeRMS,GMT,day,month,year,hours,minutes,seconds,GPS,gps_week,gps_time*<checksum><cr><lf>




6.2.3.3 PRTH<Q|S|R>,ITIM: INITIALIZE TIME AND DATE continuedExplanation of Parameters

time RMS RMSaccuracyoftheinputtime-tag(seconds) (floatingpoint,range0–999999.0).day dayofmonth(integer,range1–31).month monthofyear(integer,range1–12).year 4digityear(integer,range1980–2047).hours hoursofday(integer,range0–23).minutes minutesofhour(integer,range0–59).seconds secondsofminute(floatingpoint,range0–59.999).gps_week GPSweeknumber,includingpreGPSroll-overweeks, eg1037(integer,range0–32768)gps_TOW GPSTimeofWeekinseconds(floatingpoint,range0.0–604800.0).

6.2.3.4 PRTH<Q|S|R>, MMSV: MIN & MAX SATELLITES FOR A POSITION SOLUTIONPurpose

ThismessageSets,QueriesandRespondstotheminimumandmaximumnumberofsatellitesthereceiverwilluseforapositionsolution.Increasingtheminimumnumberofsatelliteswillimprovetheaccuracyachievedwhensufficientsatellitesareavailable,butmayreducethetimewhenasolutioncanbeproduced.Reducingthemaximumnumberofsatellitesmayreducetheaccuracyofthepositionsolution,butwilldecreasetheamountofprocessingpowerrequiredforthesolution.NotethatsettingtheMaximumsatellitestolessthan4willpreventthereceiverfromperforminga3Dpositionsolution.Likewisesettingtheminimumnumberofsatellitesgreaterthan3willpreventthereceiverperforminga2-D,altitudefixedsolution.Themaximummustbegreaterthanorequaltotheminimumnumberofsatellites.

Query Format$PRTHQ,MMSV[*checksum]<cr><lf>

Set Format$PRTHS,MMSV,[min_NSV],[max_NSV][*checksum]<cr><lf>

Response / Acknowledge Format$PRTHR,MMSV,min_NSV,max_NSV*<checksum><cr><lf>

Explanation of Parametersmin_NSV MinimumSatellitesusedforaposition/timesolution,(integer,range0-12)max_NSV MaximumSatellitesusedforaposition/timesolution,(integer,range0-12)

6.2.3.5 PRTH<Q|S|R>,MCNO: MINIMUM SIGNAL CNOPurpose

ThismessageSets,QueriesandRespondstothesatellitetrackingminimumsignaltonoiseratio(C/No)requiredforinclusionintothenavigationsolution.

Query Format$PRTHQ,MCNO[*checksum]<cr><lf>

Set Format$PRTHS,MCNO,min_CNO[*checksum]<cr><lf>

Response / Acknowledge Format$PRTHR,MCNO,min_CNO*<checksum><cr><lf>

Explanation of Parametersmin_CNO theminimumsatellitetrackingC/Norequiredforinclusionintothenavigationsolution (integer,range0–60dBHz).




6.2.3.6 PRTH<Q|S|R>,DYNA: RECEIVER DYNAMICSPurpose

ThismessageSets,QueriesandRespondstothereceiverhostdynamicsandhencethemaximumreceivertrackingdynamicsexpected.ThedegreeoffilteringperformedbythenavigationandtimingKalmanfilterisdependantontheselectedreceiverplat-form.

Query Format$PRTHQ,DYNA[*checksum]<cr><lf>

Set Format$PRTHS,DYNA, platform[*checksum]<cr><lf>

Response / Acknowledge Format$PRTHR,DYNA, platform*<checksum><cr><lf>

Explanation of Parametersplatform receiverplatform(integer,range0–10) 0 =Fixedbasestation,TimingandFrequencymodesetc. 1 =Stationary,butunknownposition 2 =Manpack/walking 3 =Automotive/LandVehicle 4 =Marine 5 =Airborne,Lowdynamics(<1g) 6 =Airborne,Mediumdynamics<2g) 7 =Airborne,Highdynamics(<4g) 8 =Airborne,VeryHighdynamics(<8g) 9 =Drone,Missiledynamics(<16g) 10 =Pureleastsquaresmode(i.e.semi-infinitedynamicsassumed)

6.2.3.7 PRTH<Q|S|R>,RSET: RE-SET THE RECEIVERPurpose

ThismessageSets,QueriesandRespondstoareceiverresetcommandwithoptionalactionssuchasclearingspe-cificdatagroupsstoredintheCW12BASICbatterybackedmemoryarea,orenteringa“sleep”mode.Thedataareasthatcanbeclearedincludesatellitealmanacs,ephemerides,andreceiverconfigurationparameters.Notethat“sleep”modearenotcurrentlysupportedintheCW12technology.Thiscommandinvokesa2secondtimeoutpriortotheresetbeinginvokedsothattherearetwochances(ona1Hzbuild)ofseeingtheacknowledgmentmessagefirst.

Query Format$PRTHQ,RSET[*checksum]<cr><lf>

Set Format$PRTHS,RSET,{[option],[option],….}[*checksum]<cr><lf>

Response / Acknowledge Format$PRTHR,RSET,{[option],[option],….}*<checksum><cr><lf>AresponseoptionofNO,indicatesthatnoresetcommandiscurrentlyactivated.

Explanation of ParametersoptionAlistofcharacterdescriptorstoindicatewhich,ifany,oftheoptionalactionsaretobeundertakenpriortothesoftwarere-set.”CONFIG”=clearthereceiverconfigurationdatainbatterybackedRAM.”EPH”=clearthesatelliteephemerisdatainbatterybackedRAM.”ALM”=clearthesatellitealmanacdatainbatterybackedRAM.”SLEEP”=entera“sleep”mode,stilltobedefined.




6.2.3.8 PRTH<Q|S|R>,ELVM: SATELLITE ELEVATION MASKPurpose

ThismessageSets,QueriesandRespondstothesatelliteelevationmaskanglebelowwhichsatellitedatawillnotbeusedinthenavigationandtimesolution.

Query Format$PRTHQ,ELVM[*checksum]<cr><lf>

Set Format$PRTHS,ELVM,nvElevMask[*checksum]<cr><lf>

Response / Acknowledge Format$PRTHR,ELVM,nvElevMask*<checksum><cr><lf>

Explanation of ParametersnvElevMask thenavigationandtimesolutionelevationmaskangleindegrees(integer,range0–90).

6.2.3.9 PRTH<Q|S|R>,COMA: COMA MODEPurpose

ThismessageSets,QueriesandRespondsComamode.Comamodeputsthereceivertosleepforapredeterminedperiodoftime.

Query Format$PRTHQ,COMA[*checksum]<cr><lf>

Set Format$PRTHS,COMA,Period[*checksum]<cr><lf>

Response / Acknowledge Format$PRTHR,COMA,Period*<checksum><cr><lf>

Explanation of ParametersPeriod Theperiodinmillisecondsthatthereceiverwillsleep.

6.2.3.10 PRTH<Q|S|R>,FRQD: FREQUENCY OUTPUT SELECTPurpose

ThismessageSets,QueriesandRespondstheFrequencyOutput.Query Format

$PRTHQ,FRQD[*checksum]<cr><lf>Set Format

$PRTHS,FRQD,Frequency[*checksum]<cr><lf>Response / Acknowledge Format

$PRTHR,FRQD,Frequency*<checksum><cr><lf>Explanation of Parameters

Frequency ThefrequencyinMegahertz(10Hz–10MHz)thatthereceiverwilloutput.e.g.for10kHz=0.010 0=switchdigitalfrequencyoff.



7. FREQUENCY OUTPUTTheCW12iscapableofproducingauserselectedfrequencyintherange10Hzto10MHz.Thefrequencyisoutputonpin10.ThefrequencyisconfiguredusingtheFRQDcommandasdetailedinsection6.2.3.10.Thefrequencyisonlyvalidwhenthereceiverhasavalid2Dpositionfixorbetter.

Figure 7 Frequency Output

Rise Time Pulse Width

Pulse width: 50 ns minimum (10 MHz)

Duty Cycle: 50:50

Risetime: maximum 10 ns (2 meter std. lead)

Output: + 3.3V Volt nominal (Vhigh > 3.0 v at 6mA out, (Vlow < v at 6mA sink)



8. BOOT OPTIONSTheCW12hastwobootmodes.TheseareselectedbythestateoftheBOOTSELsignal.WhenBOOTSELishigh,theCW12bootsfromtheFLASHthatisinternaltotheBB25IC.IfBOOTSEListiedlow,theCW12bootsfromtheROMinternaltotheBB25IC.ThisROMhasabootloaderthatpollstheserialportforbootcode.Thismodeofoperationrequiresspecialuserhan-dlingandshouldonlybeusedinconjunctionwithspecificapplicationnotes.Note:BOOTSELissampledwhentheNPORisde-asserted.Thisoccurs300msafterpowerisappliedtothemodule.TorunthebootloadertheunitmustbepoweredupwiththeBOOTSELlinesettothecorrectstate.TheNPORlineisconnectedtoapower-on-reset(POR)circuitthatisusedtoensurethatthedeviceresetscorrectlyinbrownoutconditions(MCP120-300Micro-chip).

8.1 Flash ProgrammingTheCW12contains128kFlashmemoryinternaltotheBB25ICwhichholdthemodulefirmware.TheFlashisreprogrammableinthefieldbymeansofaROMbootloaderutility.TorunthebootloadertheunitmustbepoweredupwiththeBOOTSELlinesettothecorrectstate.Aloaderprogramandabatchfileareprovidedtotransferthefirmwarebinaryimagefiletothemodule.Toreprogramthemodulefollowtheinstructionsbelow:

1) Withthemodulepowereddown,connecttheBOOTSELpintoGND

2) ConnectanyoftheCW12UARTtoCOM1ofyourPC.

3) Powertheunitup.TheCW12shouldstartbyoutputtingastreamof‘Z’charactersat38400baud.Thisshouldbe checkedoutviaaterminalprogram.Ifafterabout20secondsthere-programmingstep(4)hasn’tstarted,the streamof‘Z’’swillstopandtheexistingCW12firmwarewillrun.

4) Justaftertheunithasbeenpowered,andwhilethe‘Z’’sarebeingoutputted,run“download.bat”batchfilefroma Consolewindow.YoucaneditthisbatchfiletouseaPCportotherthanCOM1ifyouprefer.Youshouldsee:

CW12 FILE Up/DownLoader ver 1.0<C> NavSync Inc 2003

loader - loader.hex baud_rate - 38400 comm - com1 Addr - 0x060000 binary file - CW12.bin debug_mode - 2Reset the board and then ENTER key

5) Hit <Enter> and you will see: Start waiting for BootRomThenafterafewsecondsyoushouldthensee: BootRom loader foundAfterabout7-10secondsyoushouldsee S-Record loader sentThenyouwillseeastreamofdotsgoingacrossthescreenasthefirmwareisbeingdownloaded.Oncethedownloadhasfinishedyouwillsee: Image download Passed Process finished

Iferrorsareencounteredduringtheupgradeproceduresimplyresetthemoduleandstartagain.



9. NMEA CONFIGURABILITY DETAILSAvailableonlyifNMEAdatastreamisoutputonPort1oftheCW12.ThissectiondescribeshowtheNMEAoutputcanbeconfiguredfordifferentRefreshRates,ContentandBaudRates.

•UARTConfiguration(i.e.baudrate)Query:$PRTHQ,U1CM

•UARTConfiguration(i.e.baudrate)Set:$PRTHS,U1CM

•NMEAOutputConfiguration(i.e.outputfrequency)Query:$PRTHQ,U1OP

•NMEAOutputConfiguration(i.e.outputfrequency)Set:$PRTHS,U1OP

9.1 NMEA Configuration Query ($PRTHQ,U1OP):Available only if NMEA data stream is output on Port 1 of the CW12.

Thecommandtakestheform“$PRTHQ,U1OP”where1istheportnumber(Port1).

Theresponsestringisoftheform“$PRTHR,U1OP,GLL=1,GSV=4,PLT=1”ThestringisdependentontheNMEAsentencessupportedbythesystem,butlistseachsupportedsentencealongwiththeoutputintervalinsecondsofthatsentence.ANMEAchecksumoftheform“*4D”isappendedtotheoutputstring.

ThelistofcurrentlysupportedNMEAsentencesareshownbelow,togetherwiththeabbreviatednameusedintheresponsestring.

Abbrev. NMEA SentenceGLL GPGLL-GeographicPosition-LatitudelongitudeRMC GPRMC-RecommendedMinimumSpecificGNSSSentenceVTG GPVTG-CourseOverGroundandGroundSpeedGGA GPGGA-GPSFixDataGSA GPGSA-GNSSDOPSandActiveSatellitesGSV GPGSV-GNSSSatellitesinViewGRS GPGRS-GNSSRangeResidualsGST GPGST-GNSSPseudorangeErrorsStatisticsPLT POLYT–TimePLP POLYP-Position(Lat,Long)PLU POLYU-UTMpositionPLG POLYG-LocalGridpositionPLS POLYS-SatellitedataPLH POLYH-HDSTimeInformationPLI POLYI-AdditionalInformation

Anexampleresponsestringisshownbelow.Inthisexample,allsentencesareoutputeverysecond,exceptGPGSV,whichisoutputeverythreeseconds,andPOLYT,whichisnotoutputatall(i.e.thesentenceoutputisdisabled).

$PRTHR,U1OP,GLL=1,RMC=1,VTG=1,GGA=1,GSA=1,GSV=3,PLT=0,PLP=1,PLS=1,PLI=1*0C



9. NMEA Configurability Details continued

9.2 NMEA Configuration Set ($PRTHS,U1OP):Available only if NMEA data stream is output on Port 1 of the CW12.

Thecommandtakestheform“$PRTHS,U1OP,GLL=2,GGA=4,GSV=0”where1isaportnumber.Theremainderofthestringisoftheform“GLL=2,GGA=4,GSV=0”.ThespecificcontentssupportedaredependentontheNMEAsentencessupportedbythesystem.Onlythesettingswhicharetobealteredneedtobelisted.ANMEAchecksumoftheform“*4D”isappendedtotheoutputstring. ThelistofcurrentlysupportedNMEAsentencesisshownabovefortheQuerycommand.Toturnasentenceoutputoffcompletely,simplyspecifyzeroasthedurationforthatcommand.Subsequentcommandsmayreassignanoutputperiodtosentencesdisabledinthisway,effectivelyre-enablingtheoutputsentence.Thiscommandalsosupportsashortcutbymeansofan“ALL”specifier.Whenthisisencountered,theperiodspecifiedisappliedtoallsentences.Anexampleofthisisshownbelow,whereeverymessageoutputonport1willbeprintedata5-secondperiodwiththeexceptionoftheGPRMC sentence,whichwillbeoutputeverysecond,andthePOLYT sentence,whichwillbedisabled.

$PRTHS,U1OP,ALL=5,RMC=1,PLT=0

9.3 UART Configuration Query ($PRTHQ,U1CM):Disabled from standard builds. Available only if NMEA data stream is output on Port 1 of the CW12.

Thecommandtakestheform“$PRTHQ,U1CM”where1istheportnumberTheresponsestringisoftheform“$PRTHR,U1CM,38400,38400,N,1”where1istheportnumberforwhichtheinformationwasrequested.Theremainderofthestring,“38400,38400,N,1”representstheportTxbaudrate,Rxbaudrate,parityandstopbitsrespectively.ANMEAchecksumoftheform“*4D”isappendedtotheoutputstring. AlthoughtheformatofthecommandsupportstheuseofdifferentRxandTxbaudrates,thisisnotcurrentlysupportedbytheCW12platform.Consequently,theRxandTxbaudratesreturnedwillalwaysbeidentical.

9.4 UART Configuration Set ($PRTHQ,U1CM):Disabled from standard builds. Available only if NMEA data stream is output on Port 1 of the CW12.

Thecommandtakestheform“$PRTHS,U1CM,57600,57600,N,1”where1isaportnumber.Theremainderofthestring,“57600,57600,8,N,1”representstheportTxbaudrate,Rxbaudrate,parityandstopbitsrespec-tively. AlthoughtheformatofthecommandsupportstheuseofdifferentRxandTxbaudrates,thisisnotcurrentlysupportedbytheCW12platform.Consequently,theRxandTxbaudratesmustalwaysbespecifiedtobethesamevalue.Inaddition,theCW12platformdoesnotcurrentlysupporttheuseofparity,orofstopbitsettingsotherthan1stopbit.Thesupportedbaudratesare:1200,2400,4800,9600,19200,38400,57600,115200,and230400. Ifacommandisissuedwhichisbadlyformattedordoesnotadheretotheseconstraints,itwillbediscarded.ThiscommandisintendedforusewiththeNMEAstreamofdata.Cautionshouldbeexercisedwhenusingthiscommandtochangethebaudrate,sincedatamaybelostduringtheconfigurationchange. Itshouldbenotedthatthesecommandsallowthesystemtobeconfiguredat1200baud,whilerequestingthatthefullsetofNMEAsentencesbeoutputeachsecond.SuchconfigurationswillresultinNMEAcorruptionsincetheoutputNMEAdatarateexceedstheunderlyingbaudrate.



10. MISCELLANEOUS

10.1 Glossary 2D Two-dimensional3D Threedimensional(i.e.includingaltitude)AGC AutomaticGainControlAlmanac Datatransmittedbyeachsatellite,andwhichprovidestheapproximateorbitalinformationofalltheGPS satellitesconstellation(i.e.a‘timetable’).Antenna Alsocalled‘Aerial’,thedeviceforreceivingtheradiosignals.ASCII Astandarddigitalformatforalpha-numericcharacters(AmericanStandardCodeforInformationInterchange).Baud Serialdigitalcommunicationspeedunits(bitspersecond).BIT BuiltinTestCDU Control-DisplayUnitCEP CircularErrorProbabilityChannel ThesatellitetrackingunitofaGPSreceiver.Onechannelmaytrackmorethanonesatellite,by multiplexing,butforbestperformanceeachsatelliteshouldbecontinuouslytrackedbyadedicated channelsomorethan onechannelisoftenintegratedintoareceiver.CMOS Atypeofsemiconductorfabricationprocess(ComplementaryMetalOxideSemiconductor),resultingin lowpower.CMOSdevicesrequirestaticprotectionduringhandling.C/No CarriertoNoiseratio(ameasureofsignalquality)COMPort Communicationport,e.g.PCserialcommunicationportsCOM1etc.CONUS ContinentalUnitedStatesCPU CentralProcessingUnit(usuallythemicroprocessor)CTS CleartoSend(serialcommunicationhandshaking)Datum ThereferenceshapeoftheEarth’ssurfaceusedintheconstructionofamaporchart.Usuallychosenfor a‘bestfit’overtheareaofinterestandthustheDatumforvariouspartsoftheworldmaydiffer.Deltarange Smallchangesinrangebetweenasatelliteandthereceivingantenna.DoD U.S.DepartmentofDefense.DOS DiskOperatingSystem.DOP ADOP(DilutionofPosition)isafigurewhichrepresentsthepurelygeometricalcontributionofthe satellites’positionstothetotalpositionerrorbudget.LowvaluesofaDOP(1-5)meanthatthe calculatedpositionshouldbegoodwhilsthigherDOPvaluesindicateagreateruncertaintyinthe determinedposition.GoodDOPvaluesareobtainedwhensatellitesarewellspacedgeometrically,while poorvaluesresultfromavailablesatellitesallbeingvisibleinsimilardirections.WhentheDOPvalueis excessive(e.g.>100)thenneitherstand-alonenordifferentialpositionsshouldbeused.DR DeadReckoning-ameansofestimatingpresentpositionbasedonaknownstartingpositionupdated byapplyingdistanceanddirectionoftheuser’smovements.DSR DataSetReady(serialcommunicationhandshaking)DTR DataTerminalReady(serialcommunicationhandshaking)ECEF EarthCenteredEarthFixed.Ellipsoidal HeightasdefinedfromtheEarth’scenterbyareferenceHeight ellipsoidmodel(seeDatum)EMI/EMS/EMC ElectromagneticInterference(emittedfromequipment),Susceptibility(tointerferencefromother equipment),andCompatibility(EMI+EMS)EPS EmergencyPowerSupply,onlyformaintainingtheRTCdataintheRAMwhentheequipmentis powereddownENU EastNorthUp(theorderoflistingco-ordinates)Ephemeris SimilartoAlmanac,butprovidingveryaccurateorbitaldataofeachindividualsatelliteandtransmitted bythesatelliteconcernedFirmware Programresidentwithinthereceiver.GDOP GeometricalDilutionofPrecisionGeoid TheMeanSeaLevelsurfaceoftheEarthGeoid/Ellipsoid DifferencebetweentheMeanSeaLevelandtheseparationmathematicalmodelusedtodefineadatum, atthepointofinterestGHz Gigahertz,onethousandMHz(i.e.109Hz)GMT GreenwichMeanTime(similartoUTC)GPS GlobalPositioningSystemGPStime TimestandardfortheGPSsystem(secondsaresynchronouswithUTC)Hex Denotesanumberinhexadecimalformat.



HDOP HorizontalDilutionofPrecision.IC IntegratedCircuit.ICD InterfaceControlDocumentI/O Input-OutputIODE IssueofDataEphemerisIRQ InterruptRequestKalmanFilter Mathematicalprocessusedtosmoothoutmeasurementerrorsofpseudo-rangesandcarrierphasesof trackedsatellites.Forexample‘8states’referstofilteringofpositionandtime(i.e.x,y,zandt)andthe rateofchangeofeach.knot NauticalmileperhourL1 The1575.42MHzfrequencyradiatedbyGPSsatellites.L-band Thebandofradiofrequenciesbetween1and2GHz.Lithium Ametallicelement(usedinbatteries)LMT LocalMeanTime.mA Milliamp(ofcurrent)Macro Textcontainingfrequentlyusedoperationswhichcanbeexecutedasasinglecommand(DMonly).MHz Megahertz,i.e.onemillioncyclespersecond.mph MilesperHour.MSL MeanSeaLevel=geoidalheight=0MIL-STD MilitaryStandardMTIE MaximumTimeIntervalErrorMultiplexing Areceiverchannelcantrackmultiplesatellitesbyswitchingrapidlybetweenthemsoastogatherall datatransmissionsNMEA NationalMarineElectronicsAssociation.NMEA0183 Aserialcommunicationstandarddefininghardwarecompatibility,messageformats,andarangeof standardmessages.OTF On-The-Flycarrierphaseambiguityresolution.Theabilitytoresolveintegercarrierphaseambiguities inreal-timewhilemoving.n.mile InternationalNauticalMile(1852meters;6076.1feet,1.15statutemiles).ns,nSec Nanosecond,onethousandthofamicrosecond(i.e.10-9second)PC PersonalComputer(IBMcompatible)PCB PrintedCircuitBoardP-code ThePrecise(orProtected)GPScode-notavailabletocivilusers.PDOP PositionDilutionofPrecision,includinghorizontalandverticalcomponents.pps,PPS PulseperSecond,andPrecisePositioningServicePRC PrimaryReferenceClockPRN Pseudo-RandomNoisecodeuniquetoeachsatellite’smessageandthereforeusedtoidentifyeach satellite.PseudoRange Theapparentmeasured‘straightline’distancefromasatellitetothereceivingantennaatanyinstantin time,includinganyerrorscausedbysatelliteclocks,receiverclocks,refractionoftheradiowaves,etc.PSU PowerSupplyUnitRAM RandomAccessMemoryRealNumbers NumberswhichmayhavedecimalpointandfractionalcomponentResolution SmallestseparationoftwodisplayelementsRF RadiofrequencyRFI RadioFrequencyInterferenceRMS RootMeanSquareRPS RelativePositioningSystemRS232 Serialcommunicationhardwarestandard(+/-12vnom.)RS422 Aserialcommunicationhardwarestandard(differential)RTCM RadioTechnicalCommitteeforMaritimeServicesRTC Real-timeClock(maintainingapproximatetimewhenunitisoff)RTK RealTimeKinematicRTS RequesttoSend(serialcommunicationhandshaking)RXD ReceiveData(serialcommunicationtoDataTerminalor‘DTE’fromDataCommunicationEquipmentorDCE’)

10. Miscellaneous continued10.1 Glossary continued



S/A SelectiveAvailability-imposedbytheDoDtolimittheGPSperformanceavailabletocivilusers.SEP SphericalErrorProbabilitySMA Miniaturethreadedcoaxialconnector.SPS StandardPrecisionServiceSSR SolidStateRecorderSV SatelliteVehicleTNC AstandardthreadedcoaxialconnectorTSPI TimeSpacePositionInformationTTL Transistor-TransistorLogic(familyofdigitalelectroniccomponents)TTFF TimetoFirstFixTXD TransmitData(serialcommunicationfromDataTerminalor‘DTE’toDataCommunicationEquipment or‘DCE’)us,uSec Microsecond(uisfrequentlyusedfortheGreekµsymboldenoting‘micro’,onemillionthpart,10-6)UTC CoordinatedUniversalTimeUTM UniversalTransverseMercatorUART UniversalAsynchronousReceiver-transmitter(usedinserialcommunications)USNO U.S.NavalObservatoryVDOP VerticalDilutionofPrecisionWGS WorldGeodeticSystem(aworld-wideDatum,GPSworksinWGS84whichhassupersededWGS72)

10.2 Contact DetailsForfurtherNavSyncdetailsandhot-linesupportpleasecontact:

North America Customer Support International Customer Support2111ComprehensiveDrive BAY143Aurora,Illinois60505 ShannonIndustrialEstatePhone:630.236.3026 Shannon,Co.Clare,IrelandE-mail:[email protected] Phone:+35361472221

www.navsync.com E-mail:[email protected]

10.3 Internet InformationThereareseveralGPSrelatedsitesontheInternetthatareexcellentsourcestoobtainfurtherinformationaboutGPSandthecurrentstatusofthesatellites.

U.S. Coast Guard Navigation Center CivilianGPSservicenotices,generalsysteminformation,andGPSoutagereporting:www.navcen.uscg.mil/gps

U.S. Naval Observatory GeneralUSNOinformationandlinkstoUSNOtimingandotherusefulsites:www.usno.navy.mil

NAVSYNC GPS Homepage GeneralGPSinformationandlinkstootherusefulGPSsites:www.laafb.af.mil/SMC/CZ/homepage

National Marine Electronics Association (NMEA) ForinformationontheNMEAprotocolspecification:www.nmea.org

Radio Technical Commission for Marine (RTCM) ForinformationontheRTCMspecificationforDGPScorrections:www.navcen.uscg.mil/dgps/dgeninfo

General GPS Information GlossaryofGPSterms:www.gpsworld.com/resources/glossary.htm

10. Miscellaneous continued10.1 Glossary continued

CW12 User Manual

Revision Date Author Notes 0.1 R.Toma InitialDraft 0.2 R.Toma Improvedexplanationforthe@@As Added@@Aw,@@Bb,@@Bd,@@be,@@Cb 0.3 R.Toma Added,@@Co,@@Bi,@@Bf,@@Ge,@@Gf, @@Ha,@@Hb,@@Hn 0.5 R.Toma AddedCW12pinoutphysical&electricalinformation 06 R.Toma RemovedexcessinformationabouttheCW25 . andformattingthedocumenttoresemble documentsfromMotorola 0.7 R.Toma Smallreviewchanges;theredcoloredtexthasbeen changedtoreflecttheactualCW12implementation 0.8 R.Toma Added@@Az,@@Ay,@@Sz 0.8.1 R.Toma Addedexplanation@@Hamodefield Bootloadermodeexplanations Supplyripplenoise 09 12/17/07 N.Young Revisedtonewrevisionnumberingsystem Updatedtostandardlayout&featurerevisions 10 08/25/09 N.Young RevisedAcquisition/TrackingSpecs 11 03/1210 K.Loiselle GeneralSpecificationRevisions 12 05/07/10 D.Jahr 1PPSSpecificationupdate

NavSync, Ltd. EuropeBay 143

Shannon Industrial Estate

Shannon, Co. Clare, Ireland

Phone: +353 61 475 666E-mail: [email protected]

North America2111 Comprehensive Drive

Aurora, IL 60505, USA

Phone: 630.236.3026

E-mail: [email protected]

www.navsync.com

CW12 GPS User Manual - NavSync GPS User Manual Issue: V 12 ... Connector Data/Power: 10 pin (2 x 5)...

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