Garmin GP35-LVS Marine GPS System User Manual


 
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4.2 NMEA Transmitted Sentences
The subsequent paragraphs define the sentences which can be transmitted on TXD1 by the GPS 35LP
receivers.
4.2.1 Sentence Transmission Rate
Sentences are transmitted with respect to the user selected baud rate.
Regardless of the selected baud rate, the information transmitted by the GPS 35LP is referenced to the
one-pulse-per-second output pulse immediately preceding the GPRMC sentence.
The GPS 35LP 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 sensor board will transmit the selected sentences contiguously. The contiguous transmission starts
at a GPS second boundary. The length of the transmission can be determined by the following equation
and tables:
total characters to be transmitted
length = --------------------------------------------
characters transmitted per sec
Baud characters_transmitted_per_sec
300 30
600 60
1200 120
2400 240
4800 480
9600 960
19200 1920
Sentence max_characters
GPGGA 81
GPGSA 66
GPGSV 210
GPRMC 74
GPVTG 42
PGRMB 26
PGRME 35
PGRMT 50
PGRMV 32
PGRMF 82
LCGLL 44
LCVTG 39
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 the NMEA specification
transmission rate of 4800 baud.