Product specifications

107
Advanced Topics
SETUP
The opening screen for GPS Info is the place where the
connection to the GPS unit is performed. Only one program can
be attached to a GPS unit at any one time. If a connection cannot
be established check and ensure that the WayPoint
tm
software is
not running or has closed access to the GPS. The setup page
permits some control over the GPS itself. The commands include:
• The Cold Start button will reset the GPS and require a cold
start. This could take some time so only do this when you have a
clear sky view and are willing to wait until a GPS fix is obtained.
• VTG checked with add this message to the NMEA strings of
data. You should not do this unless a program specifically needs it.
• Power Save and save significant amounts of battery power but at a cost in performance.
Use this at your own discretion, but it is not recommend under difficult reception
conditions.
The WAAS switch can be used to toggle the differential correction capability on or off. Using
WAAS ties up one of the receiver channels and is not needed for use with road navigation
software.
The bottom of the screen shows NMEA messages as they appear. Its primary purpose is to
demonstrate that the GPS is actively send data and the PDA can receive it.
GPS INFO
Tapping the GPS Info tab brings up the information display. This screen shows a map of the
current satellite positions with the current reception signal strength for each satellite shown
below the map. The text data about the fix surrounds the map. It is primarily about the GPS
PVT solution.
• All GPS receivers compute PVT, Position, Velocity, and Time as the full GPS solution.
• At the top is the GPS computed UTC date, followed with the UTC time.
• GPS solutions are usually computed with respect to Universal Time Coordinated (UTC)
which used to be called GMT (Greenwich Mean Time).
• The time is computed at longitude 0 which passes through England. California is 8
hours later than UTC (7 hours during DST).