Taking the practical viewpoint of what is actually in the avionics ... Any OBS, HSI or similar instrument: Receives an analog signal that indicates the needle position. Our FGFS instrument works the same way; an analog angle is available as a property.
VOR receivers: Emits an analog signal that is angular error, in conjunction with the OBS. Our FGFS nav radio will generate the property's value this way. > Now, the problem is that such systems (as far as I can tell) expect to > drive a CDI bar on the HSI based on distance (in nm) off course. GPS receivers: Use full scale on the needle for a fixed number of miles. The number of miles varies according to whether the instrument is following an approach. Read the manual to determine what the scale is for any given operating mode. I assume our future GPS instruments will do the same ? Integrated VOR and GPS receivers: Use either of the above modes, depending on what the navigation source is. That is a feature that would be embedded in the OpenGC emulation of the unit. > As a result of playing with with routes / flight plans, one thing I > forsee in the future is driving navigation instruments from a non-radio > source (i.e something like the NAV / GPS toggle which I'm led to believe > is common in many GA craft with a GPS fitted). Where is the problem ? It just changes the assigned property source of the instrument, for which there is already a hook in the XML structure, between the NAVx and the GPSx property source as appropriate. > - we don't have an HSI. I'm pretty sure I could knock something up, Of course we do; it is intentionally disabled in the simple aircraft because those, in real life, don't have such an expensive item installed. _______________________________________________ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
