Xplane SITL 4.2.0dev - GPS disable not effective

Hi Everyone,

I have been using the SITL firmware for xplane (4.2.0dev) by downloading it from MP with no issues. I have disabled the gps using SIM_GPS_DISABLE = 1 and I could see the status on MP showing GPS: NO FIX.
However, the plane proceeded with the current mission like it had GPS Fix, and MP did not show any error messages. I could only see the error when I run the log analysis. I am just wondering, why disabling the gps had no effect on the flight behavior and why MP did not show any messages other than the GPS: No Fix status?

I have included a video of the mission, as well as a couple of screenshots from MP.



I have some familiarity with the code that interfaces ArduPilot with Xplane. As far as I can see, the ardupilot code receives data refs that include gps, altitude, velocity and many other instrument readings independently of what is set in the parameters. So the interface code needs to be updated to reject GPS data based on the parameter setting.

Thanks a lot.
That’s a very good point. I have completely forgot that I had had include the latitude and longitude data as output from Xplane when I configured it long time ago.
I’ll try that same scenario using the plane firmware instead of xplane.