I tried to install a single GTN 650 in the Cessna 172 as the position 2 unit (i.e. 650_2 as Master instead of 650_1). Licensed version, not trial. However, despite numerous attempts at modifying the plugin settings, I can not get the 650_2 to operate properly on IFR RNAV GPS approaches. The CDI (NAV1) has a red flag (and no vertical needle deflection) for vertical glide slope on a RNAV GPS LPV approach, and the STEC autopilot will not capture GS, even though the GTN settings seem to be correct for position 2. The only way I can get it to work properly is by putting the GTN 650 in position 1 (i.e. 650_1). Now things work properly once the settings are configured for the 650_1 position. NOTE: most of these tests were run with Xplane 11.50b6 with Vulcan. However, I seem to recall similar issues when I briefly ran tests under Xplane 11.41. Anyone else get it working with the GTN 650 in #2 position (with no 750 in #1 position)?

Note: possibly related issue. I previously installed the Cessna 172 aircraft mod for RXP GTN with the single GTN 650 (which is placed in the same 650_2 position) and had similar issues with the GPS approaches. But, there were also issues (according to the mod developer) because the mod aircraft had the earlier version of the STEC before it was upgraded in Xplane to the STEC 55. So, I aborted using that aircraft and removed it from the aircraft directory prior to the above tests.

Hi,

Any #2 GTN (or GNS V2) will default settings for #2, which means COM2/NAV2, GPS#2, X-Plane Copilot Side.

You can selectively choose to use a RXP GTN/GNS as an X-Plane GPS1 yet on the Copilot Side (copilot datarefs override) or Pilot Side (pilot dataref override) etc...

Make sure to choose the right settings depending on the datarefs the aircraft is using for the GPS (most likely GPS1 Pilot side thouhg)

NB: Master Device is here to arbitrate whenever 2 GPS are 'sharing' panel resources, and in the list of GPS sharing resources there is always the default stock X-Plane GPS. Therefore, if you're using a RXP GPS 1 and GPS 2, and they are each on their 'side', they're not sharing the HSI and each one will override the HSI datarefs on each side independently. In this case only RXP GPS 1 will have to be master against the stock GPS.