Owning Palette: NMEA Protocol VI
Requires: Robotics Module. This topic might not match its corresponding palette in LabVIEW depending on your operating system, licensed product(s), and target.
Use the NMEA Advanced VIs to read data from GPS receivers and form and parse NMEA sentences.
|Extract Sentences||Returns complete NMEA sentences contained in sensor data.|
|Form GPS Sentence||Creates an NMEA sentence using the data you specify for a particular sentence type. You must manually select the polymorphic instance to use.|
|Form Sentence||Creates an NMEA sentence formatted as the sentence type you specify and with the sentence data you specify. This VI also applies punctuation, a checksum, and termination characters to the sentence.|
|Get Sentence Parts||Returns an array of values contained in an NMEA sentence.|
|Get Sentence Type||Returns the type of an NMEA sentence. The first token following $ in an NMEA sentence is the sentence type. The type of a sentence defines the contents and interpretation of the sentence.|
|Parse GPS Sentence||Returns data contained in a particular type of NMEA sentence. The input sentence you specify must include valid NMEA formatting and end with a carriage return and line feed, or \r\n. You must manually select the polymorphic instance to use.|
|Validity Check||Specifies whether the formatting of an NMEA sentence is valid.|
The first token following $ in an NMEA sentence is the sentence type. The type of a sentence defines the contents and interpretation of the sentence. Sentence type tokens in GPS NMEA sentences are typically in the form of GPxxx, where xxx is the three-letter acronym of a type of GPS NMEA sentence.
Although many types of NMEA sentences exist, the Form GPS Sentence and Parse GPS Sentence VIs provide explicit support for creating and parsing a few common types of sentences. The following table describes the sentence types these VIs support.
|Sentence Type||Data Contained in Sentences|
|GGA||Time, position, and type of fix|
|GLL||Time, position, and status of fix|
|GSA||Type of fix, dilution of precision, and satellite data|
|RMC||Time, position, heading, and speed|
|VTG||Heading and speed relative to the ground|
Use the Form Sentence and Get Sentence Parts VIs to create and parse other types of sentences, respectively.