By default, an animation is played once when you use the Preview Animation
tool. You can set the animation to repeat during the preview, meaning
it will play continuously until you close the preview window.
To repeat an animation during the preview:
Select Tools
> Animation > Animation Properties, or click the Animation
Properties button on the Animation toolbar. This button is also available
in the Preview Animation window.
On the Paths page of the Animation
Properties dialog, enable the Repeat
Animation during preview check box.
Select Tools
> Animation > Animation Properties, or click the Animation
Properties button on the Animation toolbar. This button is also available
in the Preview Animation window.