User Manual

Trimble R6/R7 GPS and Trimble R8 GNSS Receivers User Guide 127
NMEA-0183 Output A
Trimble R6 and R7 GPS/R8 GNSS Receiver Operation
A.2 Common Message Elements
Each message contains:
• A message ID consisting of $GP followed by the message type. For example, the
message ID of the GGA message is $GPGGA.
• A comma
• A number of fields, depending on the message type, separated by commas
• An asterisk
• A checksum value
Below is an example of a simple message with a message ID ($GPGGA), followed by 13
fields and a checksum value:
$GPGGA,172814.0,3723.46587704,N,12202.26957864,W,2,6,1.2,18.893,M,-
25.669,M,2.0,0031*4F
A2.1 Message values
The following values can be found in NMEA messages that the receiver generates.
Latitude and longitude
Latitude is represented as ddmm.mmmm and longitude is represented as
dddmm.mmmm, where:
• dd or ddd is degrees
• mm.mmmm is minutes and decimal fractions of minutes
Direction
Direction (north, south, east, or west) is represented by a single character: N, S, E, or W.
Time
Time values are presented in Universal Time Coordinated (UTC) and are represented
as hhmmss.cc, where:
• hh is hours, from 00 to 23
• mm is minutes
• ss is seconds
• cc is hundredths of seconds