Campbell Scientific GPS16X-HVS GPS Receiver - Manual (Page 15)

GPS16X-HVS GPS Receiver
The GPS() instruction has the following syntax:
GPS(GPSArray,ComPort,TimeOffset,MaxTimeDiff,NMEAStrings)
Description of the parameters follows:
GPSArray The GPSArray parameter is the variable in which to store the
information returned by the GPS. Fifteen values are returned.
If this array is not dimensioned to 15, values will be stored to
fill the array and no error will be returned. If no values are
available, NAN will be returned. The following values are
returned by the GPS:
Array(1) = Latitude, degrees
Array(2) = Latitude, minutes
Array(3) = Longitude, degrees
Array(4) = Longitude, minutes
Array(5) = Speed over ground, knots
Array(6) = Course over ground, degrees
Array(7) = Magnetic variation (positive = East, negative =
West)
Array(8) = Fix Quality (0 = invalid, 1 = GPS, 2 = differential
GPS, 6 = estimated)
Array(9) = Number of Satellites
Array(10) = Altitude, meters
Array(11) = Pulse per second (PPS) length, microseconds
Array(12) = Seconds since last GPRMC sentence
Array(13) = GPS Ready, 10 = ready
Array(14) = Maximum clock change, milliseconds (10 msec
resolution)
Array(15) = Clock change count
ComPort The ComPort parameter is the control port pair to which the
GPS device is attached. Valid options are COM1 (C1/C2),
COM2 (C3/C4), COM3 (C5/C6), and COM4 (C7/C8). Rx is
used to read in the NMEA sentences and Tx is used to monitor
the PPS from the GPS. This instruction defaults to a baud rate
of 38,400 bps. If a different baud rate is required, use the
SetStatus() instruction to override the default.
TimeOffset The TimeOffset parameter is the local time offset, in seconds,
from UTC.
MaxTimeDiff The MaxTimeDiff parameter is the maximum difference in
time between the datalogger clock and the GPS clock that will
be tolerated before the clock is changed. If a negative value is
entered, the clock will not be changed.
For dataloggers prior to hardware revision 08, the
MaxTimeDiff parameter should not be set to 0. A minimum
value of 20 ms is recommended. With this hardware, when a
GPS() instruction is in the program the clock is checked each
second (regardless of how often the GPS() instruction is run).
The clock is set if any difference is found. This can result in
the clock being set each second, resulting in skipped records in
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