Your cam has a module to set up your draw length.
The Draw stop is adjustable so you can modify your draw until it will be perfect for you. Some people like less Letoff, some people want a 'harder wall'. Some things you can achieve with changing the position of the drawstop.
Did you get all 6 modules with your bow? If not you should go to Dicks and get them. They should also be able to get you a manual.
If not you can get one online:
(2) Martin ShadowCat 2010