Garmin GPS16 GPS Receiver User Manual


 
190-00228-20 GPS 16/17 Technical Specifications Rev. C
Page 16
4.2 Transmitted NMEA 0183 Sentences
The subsequent paragraphs define the sentences that can be transmitted on COM 1 by the GPS sensor.
4.2.1 Sentence Transmission Rate
Sentences are transmitted with respect to the user selected baud rate.
The GPS sensor will transmit each sentence (except where noted in particular transmitted sentence
descriptions) at a periodic rate based on the user selected baud rate and user selected output sentences. The
GPS sensor will transmit the selected sentences contiguously. The length of the transmission can be
determined by the following equation and Tables 2 and 3:
total characters to be transmitted
length of transmission = ---------------------------------------------
characters transmitted per second
Sentence Output by Default? Maximum Characters
GPRMC
74
GPGGA
82
GPGSA
66
GPGSV
70
PGRME
35
GPGLL 44
GPVTG 42
PGRMV 32
PGRMF 82
PGRMB * 40
PGRMM
32
PGRMT Once per minute 50
* Except GPS 16A
Table 2: NMEA 0183 Output Sentence Order and Size
Baud Characters per Second
300 30
600 60
1200 120
2400 240
4800 480
9600 960
19200 1920
38400 ** 3840
Table 3: Characters per Second for Available Baud Rates
** GPS 16A Only
The maximum number of fields allowed in a single sentence is 82 characters including delimiters. Values
in the table include the sentence start delimiter character “$” and the termination delimiter <CR><LF>. The
factory set defaults will result in a once-per-second transmission at 4800 baud, which is the NMEA 0183
specification transmission rate.
4.2.1.1 GPS 16LVS, 16HVS, and GPS 17HVS (not 17N)
Regardless of the selected baud rate, the information transmitted by the GPS sensor is referenced to the
one-pulse-per-second output pulse immediately preceding the GPRMC sentence, or whichever sentence is
output first in the burst (see Table 2 above).
4.2.1.2 GPS 16A
Sentences are transmitted at a fixed 200-millisecond interval.