16
If the target sentence is configured for high transmission priority, then this sentence will be transmitted every time
the GPS sensor produces a new positioning estimate. If the target sentence is configured for low priority, then it will
be transmitted at least once per second in the bandwidth that remains available after all high priority sentences are
transmitted. If sensor is configured to operate at positioning rate of 10 times per second, enabled high priority
sentences will be transmitted every 100ms and enabled low priority sentences will be transmitted in remaining
bandwidth available in each 100ms interval. This priority scheme provides flexible configuration of NMEA0183
output. It provides a way to output maximum amount of information, while still maintain timing accuracy of high
priority sentences.
Sending the sentence “$PGRMO,GPALM,1” will cause the GPS sensor to transmit all stored almanac information
for GPS satellites. Transmission of all other NMEA 0183 output sentences will be temporarily suspended.
Sending the sentence “$PGRMO,GLMLA,1” will cause the GPS sensor to transmit all stored almanac information
for GLONASS satellites. Transmission of all other NMEA 0183 output sentences will be temporarily suspended.
Sending the sentence “$PGRMO,,G” will cause the COM port to change to Garmin Data Transfer format for the
duration of the power cycle. The Garmin mode is required for GPS 19x HVS series product software updates.
4.2
TRANSMITTED NMEA 0183 SENTENCES
The subsequent paragraphs define the sentences that can be transmitted by the GPS 19x HVS.
4.2.1
Sentence Transmission Rate
Sentences are transmitted with respect to the user selected baud rate.
The GPS sensor will transmit sentences (except where noted in particular transmitted sentence descriptions) at a
periodic rate based on following parameters:
-
user selected positioning update rate (1,5 or 10 Hz)
-
user selected serial baud rate
-
user selected output sentences and their priority
The GPS sensor will transmit the selected sentences continuously. 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
Output rate (times/sec)
RMC
74
1,5,10
GGA
82
1,5,10
GSA
66
1
GSV
70
1
PGRME
35
1,5,10
GLL
44
1,5,10
VTG
42
1,5,10
GNS
82
1,5,10
PGRMV
32
1,5,10
PGRMF
82
1,5,10
PGRMB
40
1,5,10
PGRMM
PGRMT
50
once per minute
Table 2: NMEA 0183 Output Sentence Order and Size
Baud
Characters per Second
4800
480
9600
960
19200
1920
38400
3840
Table 3: Characters per Second for Available Baud Rates