I connected an alexmos 32 bit controller to Pixhawk 4 via RC_serial and found that I can't calibrate Initial angle and RC Sub-Trim because these options are not working. After connecting the voltage, the gimbal does not center with the External IMU (Pixhawk4) and tilts in the Tilt axis.
In tab "MavLink control mode" when I have set up "All axis" the speed of follow YAW can't be control like other follow parameters. When I have set up “Controls ROLL and PITCH axes only" I can control parameters of follow YAW.