GPS16X-HVS GPS Receiver
13
ComPort
The
ComPort
parameter is the control terminal 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 data logger 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 data loggers 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
the data table(s). This restriction does not apply to hardware
revisions 08 or greater.
NMEAStrings
The
NMEAStrings
parameter is the string array that holds the
NMEA sentences. If it exists, the GPRMC sentence will reside
in NMEAStrings(1), and the GPGGA sentence will reside in
NMEAStrings(2). Any other sentences will reside in
subsequent indexes into the array (on a first-in basis). Once an
index in the array is used to store a particular sentence, that
sentence will always be stored in that location when updates to
the sentence are received.
8.2 Example Program Using GPS() Instruction
The following wiring and short program provide an example of using the
GPS()
instruction with the Garmin GPS16X-HVS.
