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NMEA Transmitted Sentences
This section defines the sentences which can be output by the DGPS 53. (GPALM,
GPGGA, GPGSA, GPGSV, GPRMC, GPVTG, PGRME, PGRMT, PGRMV, PGRMF, LCGLL,
LCVTG)
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 DGPS 53 is referenced to the
one-pulse-per-second output pulse immediately preceding the GPRMC sentence.
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.
Transmitted Time
The DGPS 53 outputs UTC (Coordinated Universal Time) date and time of day in the
transmitted sentences. Prior to the initial position fix, the date and time of day are
provided by the on-board clock. After the initial position fix, the date and time of day are
calculated using GPS satellite information and are synchronized with the one-pulse-per-
second output. The DGPS 53 uses information obtained from the GPS satellites to add or
delete UTC leap seconds and correct the transmitted date and time of day.
Global Positioning System Almanac Data (ALM)
$GPALM,<1>,<2>,<3>,<4>,<5>,<6>,<7>,<8>,<9>,<10>,<11>,<12>,<13>,<14>,<15>
*hh<CR><LF>
Almanac sentences are not normally transmitted. Almanac transmission can be initiated by sending
the sensor board a $PGRMO,GPALM,1 command. Upon receipt of this command the sensor board
will transmit available almanac information on GPALM sentences. During the transmission of
almanac sentences other NMEA data output will be temporarily suspended.
Reference the Alamanac (ALM) sentence on page 11 for <field information>.
Using the
DGPS 53
