GNS Disable for Hot-Swapping
Many planes attempt to provide the user with a collection of user-selectable avionics configurations to fit individual preferences, such as supporting a GTN750 as a swappable option with a GNS series navigator. There are generally two ways that this is accomplished. One is to provide a different panel for each particular configuration. The second is to load all the instruments into one panel and use a selector of some sort to show or hide individual instrument nodes based upon the user-selected configuration.
The GNS has always been compatible with the first approach, but in earlier releases was not fully compatible with the second. However, with version 1.0.3 we have developed a way to allow aircraft developers to unload the GNS instrument completely (including its internal autopilot, systems, and touchscreen handling) when they have other avionics systems loaded.
This is accomplished by setting a new LVAR, L:XMLVAR_GPS_DISABLED_<templateID>_<instrumentIndex>, to true for each instrument to be disabled. This must be done individually for each instrument. For example, in a plane with one 530 and one 430, with both having an instrument index of 1, you would set these LVars to true or 1:
L:XMLVAR_GPS_DISABLED_AS530_1L:XMLVAR_GPS_DISABLED_AS430_1
When you wish to re-enable the GNS units, set those values to false or 0 and they will take over the system.