190-00228-21 GPS 16/17 Technical Specifications Rev. APage 134.1.2 Sensor Initialization Information (PGRMI)The $PGRMI sentence provides information used to initialize the GPS sensor’s set position and time used forsatellite acquisition. Receipt of this sentence by the GPS sensor causes the software to restart the satellite acquisitionprocess. If there are no errors in the sentence, it will be echoed upon receipt. If an error is detected, the echoedPGRMI sentence will contain the current default values. Current PGRMI defaults (with the exception of theReceiver Command, which is a command rather than a mode) can also be obtained by sending $PGRMIE to theGPS sensor.$PGRMI,<1>,<2>,<3>,<4>,<5>,<6>,<7>*hh<1> Latitude, ddmm.mmm format (leading zeros must be transmitted)<2> Latitude hemisphere, N or S<3> Longitude, dddmm.mmm format (leading zeros must be transmitted)<4> Longitude hemisphere, E or W<5> Current UTC date, ddmmyy format<6> Current UTC time, hhmmss format<7> Receiver Command, A = Auto Locate, R = Unit Reset4.1.3 Sensor Configuration Information (PGRMC)The $PGRMC sentence provides information used to configure the GPS sensor’s operation. Configurationparameters are stored in non-volatile memory and retained between power cycles. The GPS sensor will echo thissentence upon its receipt if no errors are detected. If an error is detected, the echoed PGRMC sentence will containthe 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<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 validvalues. Otherwise, fields <4> through <8> must be null. Refer to Appendix A: Earth Datums for a list ofearth datums 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, 1 = 1200, 2 = 2400, 3 = 4800, 4 = 9600, 5 = 19200, 6 = 300, 7 = 600, 8 = 38400<11> Velocity filter, 0 = No filter, 1 = Automatic filter, 2 to 255 = Filter time constant (e.g., 10 = 10 secondfilter)<12> PPS mode, 1 = Off, 2 = On<13> PPS pulse length, 0 though 48 = (n+1)*20 ms.Example: n = 4 corresponds to a 100 ms wide pulse<14> Dead reckoning valid time 1to 30 (sec)All configuration changes take affect after receipt of a valid value except baud rate and PPS mode. Baud rate andPPS mode changes take effect on the next power cycle or an external reset event.
