Additional Sensor Configuration Information (Pgrmc1) - Garmin GPS 25 LP Technical Specification

between power cycles. The GPS 25LP will echo this sentence upon its receipt if no
errors are detected. If an error is detected, the echoed PGRMC sentence will contain
the current default values. Current default values can also be obtained by sending
$PGRMCE to the board.
$PGRMC,<1>,<2>,<3>,<4>,<5>,<6>,<7>,<8>,<9>,<10>,<11>,<12>,<13>,<14>*hh<CR
><LF>
<1> Fix mode, A = automatic, 2 = 2D exclusively (host system must supply altitude),
3 = 3D exclusively
<2> Altitude above/below mean sea level, -1500.0 to 18000.0 meters
<3> Earth datum index. If the user datum index (96) is specified, fields <4> through
<8> must contain valid values. Otherwise, fields <4> through <8> must be null.
Refer to Appendix A for a list of earth datums and the corresponding earth datum
index.
<4> User earth datum semi-major axis, 6360000.0 to 6380000.0 meters (.001 meters
resolution)
<5> User earth datum inverse flattening factor, 285.0 to 310.0 (10
<6> User earth datum delta x earth centered coordinate, -5000.0 to 5000.0 meters (1
meter resolution)
<7> User earth datum delta y earth centered coordinate, -5000.0 to 5000.0 meters (1
meter resolution)
<8> User earth datum delta z earth centered coordinate, -5000.0 to 5000.0 meters (1
meter resolution)
<9> Differential mode, A = automatic (output DGPS data when available, non-DGPS
otherwise),
<10> NMEA Baud rate, 1 = 1200, 2 = 2400, 3 = 4800, 4 = 9600, 5 = 19200, 6 = 300, 7
= 600
<11> Velocity filter, 0 = No filter, 1 = Automatic filter, 2-255 = Filter time constant (10 =
10 second filter
<12> PPS mode, 1 = No PPS, 2 = 1 Hz
<13> PPS pulse length, 0-48 = (n+1)*20msec. Example n = 4 ð 100 msec pulse
<14> Dead reckoning valid time 1-30 (sec)
All configuration changes take effect after receipt of a valid value except baud rate and
PPS mode. Baud rate and PPS mode changes take effect on the next power cycle or
an external reset event.
4.1.4

Additional Sensor Configuration Information (PGRMC1)

The $PGRMC1 sentence provides additional information used to configure the sensor
board operation. Configuration parameters are stored in non-volatile memory and
retained between power cycles. The GPS 25LP will echo this sentence upon its receipt
D = differential exclusively (output only differential fixes)
18
resolution)
-9