EndRun Tempus LX GPS, User Manual

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T e m p u s L X G P S U s e r M a n u a l 82
A P P E N D I X F
83 T e m p u s L X G P S U s e r M a n u a l
S Y S P L E X O R S E R I A L T I M E O U T P U T
NMEA-0183 Format
The National Marine Electronics Association (NMEA) has developed a specification that defines the
interface between various pieces of marine electronic equipment. This standard defines “sentences”
that contain GPS position, navigation, time, and other information. Sentences that have been imple-
mented in the Tempus LX are GGA, GLL, GSA, RMC and ZDA. Your Tempus LX can output 1, 2
or 3 of these sentences per second. The selected sentences must be specified at the time of order and
set up at the factory.
Not all information defined in the NMEA-0183 sentences is available from the GPS receiver resident
in the Tempus LX. Following are the definitions for the NMEA sentences as implemented in this
product:
NOTE: Up to 3 sentences may be transmitted per second. The first character (“$”) of the first sen-
tence is the “on-time” character. Once the unit is locked to GPS, the leading edge of the start bit of
the “on-time” character is transmitted within 100 microseconds of the beginning of the second.
GGA (GPS Fix Data)
The GGA sentence contains the time, position, and fix related data. An example is below:
$GPGGA,173423.00,3827.030,N,12244.020,W,1,08,1.2,14.5,M,,,,0000*72<CR><LF>
Msg ID $GPGGA
Field 1 173423.00 UTC time of fix (hhmmss.ss)
Field 2 3827.030 Latitude in ddmm.mmm
Field 3 N Direction of latitude (N=north, S=south)
Field 4 12244.020 Longitude in dddmm.mmm
Field 5 W Direction of longitude (W=west, E=east)
Field 6 1 Fix quality indicator (0=fix not valid, 1=GPS fix)
Field 7 08 Number of SVs in use, 00-08
Field 8 1.2 HDOP (horizontal dilution of precision)
Field 9 14.5 Altitude above WGS84 ellipsoid (we do not calculate mean sea level)
Field 10 M “M” indicates altitude is in meters
Field 11 empty field Height of geoid (mean sea level)
Field 12 empty field Units of geoidal separation
Field 13 empty field Time in seconds since last DGPS update
Field 14 0000 DGPS station ID number
Checksum *72
Msg End <CR><LF>