GPS and SerialGPS objects
RawData is a read-only property that contains raw data formatted according to the National Marine Electronics Association (NMEA) 0183 standard. NMEA-0183 data is transmitted in “sentences”, each of which typically begins with an identifier that consists of a dollar sign, two-letter talker ID, and three-letter sentence ID. This identifier determines the meaning of each of the data fields in the rest of the sentence. The data fields follow the identifier and are separated by commas.
The RawData property returns the NMEA sentences that are in the input buffer. The string is not parsed for validity and there is no guarantee that the data is valid or correlated with the recent fix, satellite, or heading reading.
For GPS objects, RawData is first populated after the Open call. It contains the entire contents of the string literal or data file used to open the GPS object. After the first successful GetFix, GetHeading, or GetSatellitesInView request, RawData contains the NMEA sentences that were parsed up to and including the $GPGGA sentence that was actually processed. If a second request is issued, parsing begins with the sentence following the last $GPGGA sentence and completes with the next sentence found. After successfully obtaining the second $GPGGA sentence, the RawData property is updated accordingly.
RawData is not updated if an error occurs or the end of a buffer is reached.
For SerialGPS objects, RawData is populated in a similar manner, except that the property is not populated during an Open call.
Type the value in the RawData box on the General page of the Object’s Properties view.
The RawData property takes a string value. This example writes the RawData property to a single line edit box:
string myRawData GPS myGPS
Integer li_rc myGPS = CREATE GPS li_rc = myGPS.Open() ... myRawData = myGPS.RawData sle_1.txt = "Raw data: " + myRawData
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