190-00879-08
GPS 18x Technical Specifications
Rev. B
Page 13
4.1.2
Sensor Initialization Information (PGRMI)
The $PGRMI sentence provides information used to initialize the GPS sensor’s set position and time used for
satellite acquisition. Receipt of this sentence by the GPS sensor causes the software to restart the satellite acquisition
process. If there are no errors in the sentence, it will be echoed upon receipt. If an error is detected, the echoed
PGRMI sentence will contain the current default values. Current PGRMI defaults (with the exception of the
Receiver Command, which is a command rather than a mode) can also be obtained by sending $PGRMIE to the
GPS sensor.
$PGRMI,<1>,<2>,<3>,<4>,<5>,<6>,<7>*hh<CR><LF>
<1>
Latitude, ddmm.mmm format for GPS 18x PC/LVC; ddmm.mmmmm format for GPS 18x-
5Hz (leading zeros must be transmitted)
<2>
Latitude hemisphere, N or S
<3>
Longitude, ddmm.mmm format for GPS 18x PC/LVC; ddmm.mmmmm format for GPS
18x-5Hz (leading zeros must be transmitted)
<4>
Longitude hemisphere, E or W
<5>
Current UTC date, ddmmyy format
<6>
Current UTC time, hhmmss format for GPS 18x PC/LVC; hhmmss.s format for GPS 18x-
5Hz
<7>
Receiver Command, A = Cold Start, R = Unit Reset
4.1.3
Sensor Configuration Information (PGRMC)
The $PGRMC sentence provides information used to configure the GPS sensor’s operation. Configuration
parameters are stored in non-volatile memory and retained between power cycles. The GPS sensor 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 GPS sensor.
$PGRMC,<1>,<2>,<3>,<4>,<5>,<6>,<7>,<8>,<9>,<10>,<11>,<12>,<13>,<14>*hh<CR><LF>
<1>
Fix mode, A = Automatic, 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: Earth Datum List
for a list of earth datum and the corresponding earth datum index.
<4>
User earth datum semi-major axis, 6360000.000 to 6380000.000 meters (.001 meters resolution)
<5>
User earth datum inverse flattening factor, 285.0 to 310.0 (10
-9
resolution)
<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), D =
Differential exclusively (output only differential fixes)
<10>
NMEA 0183 Baud rate, 3 = 4800, 4 = 9600, 5 = 19200, 6 = 300, 7 = 600,
8 = 38400 (for GPS 18x-5Hz only)
<11>
No Effect (This field is not used on this model and is included only for backwards compatibility)
<12>
Measurement Pulse Output, 1 = Disabled, 2 = Enabled
<13> Measurement
Pulse
Output
pulse length, (n+1)*20 ms
For 18 LVC/PC n = 0 through 48 (max. 980 ms)
For GPS 18x-5Hz n = 0 through 8 (max. 180 ms)
Example: n = 4 corresponds to a 100 ms wide pulse
<14>
Dead reckoning valid time 1 to 30 sec. for the GPS 18x PC/LVC
or 0.2 to 30.0 sec. for the GPS 18x-5Hz
All configuration changes take effect after receipt of a valid value except baud rate and Measurement Pulse Output
mode. Baud rate and Measurement Pulse Output mode changes take effect on the next power cycle or an external
reset event.
