Dear Daniel and Sander,
Thank you very much for your comments. It help me very much to understood the sytem quite more.
I have select the airframe type: VTOL Quad Tailsitter - Vehicle: Quadrotor X Tailsitter - Firmware version: 1.6.2dev
On the Flight mode page I have select one switch from the RC for "VTOL mode switch"
The mode channel if have set to "Stabilized", "Attitude" and "Manual" for the begin.
According to the manual the AUX3 output shpild be for the plane motor and the Main output 1 to 4 for the copter motors.
I have connect a ozilloscope to AUX3 and Main1.
If I ARM the system (the mode switch is on Manual" and the VTOL switch is on "0" the output on Main1 works like estimated. If I switch the VTOL switch to "1" the Main1 go to 1100us and keep stable there regardless which stick I move.
This means to me that the VTOL switch is working also the outputs Main1 to Main4.
@Sander, I have look for a parameter to switch off the quadchute - but didn't find.
I found the parameter VT_FW_MIN_ALT (QuadChute). The setting is "0"
So the plane motor test is still a problem.
Thanks and best regards,