xc mode is available only with Animation.
In
Autokey mode, Animation:
- Automatically positions the key points, based on the position of the time bar
-
Computes the animation so that the components reach the specified positions
-
Computes the motion of assembly components from one position to the next using interpolation
When you select Autokey 
, the MotionManager places key points automatically. Key points are placed at times based on your actions with the model.
When you clear Autokey , you must place key points manually.