Gazebo PWM conversion

Hey All,

im struggeling with the dynamic behavior of my model in Gazebo. On the PX4 side all Actuator Outputs are correct even in PWM. When i start my simulation and set no actuator input, so my PWM signals are 1500 for every channel, the Model thrusts in motor direction. Also i am not able to give negative thrust.

Where can i find the App in Gazebo which converts the PWM signals of the PX4 to the control calues in Gazebo?

Thanks a lot!