190-00228-20 GPS 16/17 Technical Specifications Rev. CPage 134.1.2 Sensor Initialization Information (PGRMI)The $PGRMI sentence provides information used to initialize the GPS sensor’s set position and time usedfor satellite acquisition. Receipt of this sentence by the GPS sensor causes the software to restart thesatellite acquisition process. If there are no errors in the sentence, it will be echoed upon receipt. If an erroris 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 beobtained by sending $PGRMIE to the GPS sensor.$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 $PGRMC sentence provides information used to configure the GPS sensor’s operation. Configurationparameters are stored in non-volatile memory and retained between power cycles. The GPS sensor willecho this sentence upon its receipt if no errors are detected. If an error is detected, the echoed PGRMCsentence will contain the current default values. Current default values can also be obtained by sending$PGRMCE to the GPS sensor.$PGRMC,<1>,<2>,<3>,<4>,<5>,<6>,<7>,<8>,<9>,<10>,<11>,<12>,<13>,<14>*hh<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> mustcontain valid values. Otherwise, fields <4> through <8> must be null. Refer to Appendix A:Earth Datums for a list of earth datums and the corresponding earth datum index.<4> User earth datum semi-major axis, 6360000.000 to 6380000.000 meters (.001 metersresolution)<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 meterresolution)<7> User earth datum delta y earth centered coordinate, -5000.0 to 5000.0 meters (1 meterresolution)<8> User earth datum delta z earth centered coordinate, -5000.0 to 5000.0 meters (1 meterresolution)<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<11> Velocity filter, 0 = No filter, 1 = Automatic filter, 2 to 255 = Filter time constant (e.g., 10 = 10second filter)<12> PPS mode, 1 = Off, 2 = 1 Hz<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 effect after receipt of a valid value except baud rate and PPS mode. Baudrate and PPS mode changes take effect on the next power cycle or an external reset event.
