Garmin GPS 18x 010-00321-37 Manual De Usuario
Los códigos de productos
010-00321-37
190-00879-08
GPS 18x Technical Specifications
Rev. B
Page 20
4.2.15 DGPS Beacon Information (PGRMB)
Note: The GPS 18x products do not support PGRMB at this time.
$PGRMB,<1>,<2>,<3>,<4>,<5>,K,<6>,<7>,<8>*hh<CR><LF>
<1>
No Effect (This field is not used on this model and is included only for backwards compatibility)
<2>
No Effect (This field is not used on this model and is included only for backwards compatibility)
<3>
No Effect (This field is not used on this model and is included only for backwards compatibility)
<4>
No Effect (This field is not used on this model and is included only for backwards compatibility)
<5>
Distance to beacon reference station in kilometers
<6>
No Effect (This field is not used on this model and is included only for backwards compatibility)
<7>
DGPS fix source (R = RTCM, W = WAAS, N = Non-DGPS Fix)
<8>
DGPS mode, A = Automatic, W = WAAS Only, R = RTCM Only, N = None (DGPS disabled)
4.3 BAUD RATE SELECTION
Baud rate selection can be performed by sending the appropriate configuration sentence to the GPS sensor as
described in the $PGRMC
described in the $PGRMC
, field <10>.
4.4 MEASUREMENT PULSE OUTPUT (GPS 18x LVC & 18x-5Hz ONLY)
4.4.1 One-Pulse-Per-Second (PPS) Output (GPS 18x LVC Only)
The highly accurate one-pulse-per-second (PPS) output is provided for applications requiring precise timing
measurements. After the initial position fix has been calculated, the PPS signal is generated and continues until the
unit is powered down. The rising edge of the signal is aligned to the start of each GPS second within 1
measurements. After the initial position fix has been calculated, the PPS signal is generated and continues until the
unit is powered down. The rising edge of the signal is aligned to the start of each GPS second within 1
μs for all
conditions in which the re ceiver has reported a valid and accurate position for at least the previous 4 seconds.
The NMEA 0183 sentences that follow each rising edge of the PPS signal tell when you were and where you were at
that previous rising edge of the PPS signal, beginning with the GPRMC sentence as the lead sentence in any
particular NMEA 0183 record.
that previous rising edge of the PPS signal, beginning with the GPRMC sentence as the lead sentence in any
particular NMEA 0183 record.
Regardless of the selected baud rate, the information transmitted by the GPS 18x series products is referenced to the
pulse immediately preceding the NMEA 0183 RMC sentence.
pulse immediately preceding the NMEA 0183 RMC sentence.
The accuracy of the one-pulse-per-second output is maintained only while the GPS receiver is computing a valid
position fix. To obtain the most accurate results, the one-pulse-per-second output should be calibrated against a local
time reference to compensate for cable and internal receiver delays and the local time bias.
position fix. To obtain the most accurate results, the one-pulse-per-second output should be calibrated against a local
time reference to compensate for cable and internal receiver delays and the local time bias.
The default pulse width is 100 ms, however; it may be programmed in 20 ms increments between 20 ms and 980 ms
as described in $PGRMC section
as described in $PGRMC section
, field <13>.
4.4.2 Five-Pulse-Per-Second Output (GPS 18x-5Hz Only)
The highly accurate five-pulse-per-second output is provided for applications requiring precise timing
measurements. After the initial position fix has been calculated, the GPS 18x-5Hz generates the pulse signal, which
continues until power down. The rising edge of the signal is aligned to the start of each GPS second within 1
measurements. After the initial position fix has been calculated, the GPS 18x-5Hz generates the pulse signal, which
continues until power down. The rising edge of the signal is aligned to the start of each GPS second within 1
μs for
all conditions in which the receiver has reported a valid and accurate position for at least the previous 4 seconds.
The NMEA 0183 sentences that follow each rising edge of the Measurement Pulse Output signal tell when and
where you were at that previous rising edge of the Measurement Pulse Output signal, beginning with the GPRMC
sentence as the lead sentence in any particular NMEA 0183 record.
where you were at that previous rising edge of the Measurement Pulse Output signal, beginning with the GPRMC
sentence as the lead sentence in any particular NMEA 0183 record.
Regardless of the selected baud rate, the information transmitted by the GPS 18x-5Hz is referenced to the preceding
five times per-second output pulse.
five times per-second output pulse.
The accuracy of the five-pulse-per-second output is maintained only while the GPS 18x-5Hz can compute a valid
position fix. To obtain the most accurate results, the five-pulse-per-second output should be calibrated against a
local time reference to compensate for cable and internal receiver delays and the local time bias.
position fix. To obtain the most accurate results, the five-pulse-per-second output should be calibrated against a
local time reference to compensate for cable and internal receiver delays and the local time bias.
The default pulse width is 100 ms, however; it may be programmed in 20 ms increments between 20 ms and 180 ms
as described in $PGRMC section
as described in $PGRMC section
, field <13>.