User manual

XCSoar User Manual
GPS status
GPS status icons and text may appear on the bottom edge of the
map display to indicate:
Waiting for GPS fix : The GPS may have a 2D fix, better reception or additional
time to search for satellites is required. The aircraft symbol
disappears while there is no 3D fix.
GPS not connected : No communication with the GPS is received. This indicates
an error in the Comm port settings or the GPS device may
be disconnected or switched off.
When the GPS is not connected for more than one minute, XCSoar
automatically attempts to restart communication with the device
and will then resume waiting. This method has shown to provide
the most reliable way of recovering from communication errors.
XCSoar can handle up to two GPS sources and it uses them to
provide redundancy. This means that if the primary GPS source
drops out, XCSoar will use the GPS data from the second source.
If both sources have valid fixes, the second source is ignored. For
this reason, it is recommended to have the GPS source with the
best antenna or reliability as the primary device.
GPS altitude
Some older GPS units (and some new ones) do not output altitude
relative to mean sea level, rather they output elevation with respect
to the WGS84 ellipsoid. XCSoar detects when this occurs and ap-
plies the ellipsoid to geoid offset according to an internal tabulated
data at two degree spacing. This is not required for FLARM units
or Altair Pro, which correctly output MSL altitude.
8.3 Switch inputs
XCSoar supports monitoring of switches and sensors connected to
the host computer, for the purpose of providing situational aware-
ness feedback, alerts, or as general-purpose user-interface input
devices. Several mechanisms are available for interfacing to switches
and sensors:
Serial device : Certain intelligent variometers such as triadis engineering’s
Vega have multiple airframe switches and pass this informa-
tion on to the PDA or EFIS as special NMEA sentences.
1-Wire device : triadis engineering’s Altair glide computer and Vega vari-
ometer provide a 1-Wire peripheral bus to which various
digital and analog sensors can be attached.
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