Being unfamiliar with the Parker bows, it's hard for me to give EXACT instructions. I'm assuming that the Parker Single cams have a draw stop. The key to getting proper rotation on a single cam bow is to get the cam to rotate to that drawstop and not before or beyond it for the designated DL. If you find that the bow is under/over rotating for your particular DL, you are out of time and adjustments need to be made. A lot of mfg's have marks on their cams to show when a cam is in time at full rest. You may want to check your owners manual and see if the Parker cams have something such as that. I wish I could be more help but the Parker line is not something that is very popular in these parts and as such I have no experience with them..
Update- I just found out that they might not have any markings on the cam. The string should come off the cam in a straight line right where the lobe begins to round over. The cam should not bend the string at the lobe or have a gap between the string and cam at the lobe. Hopefully that makes sense to ya.