Parameter Curve Out-of-Range Types
Main toolbar > Curve Editor (Open) > Controller menu > Out-of-Range Types
Graph Editors > Track View - Curve Editor > Curves: Track View Toolbar > Parameter Curve Out-of-Range Types
With Parameter Curve Out-of-Range Types you can specify how an object is to behave outside the range of the keys you've defined.
Use Parameters Curve Out-of-Range Types to create loops and cycles. The idea is to create a short pattern of keys that produce an animated effect, and then loop or cycle through those keys throughout the animation.
Using the Parameter Curve Out-of-Range Types dialog, you select from four ways for repeating your animation and two ways for applying a linear value.
Tip: Use the Create Out of Range Keys utility, found in Track View Utilities, to turn the parameter out-of-range animation into editable keyframes.