You can avoid to add points to the frequent diner's account for the portion of the transaction paid with redeemed frequent diner points. For example, if a check of $100.00 is paid with $20.00 or redeemed points and with $80.00 of another payment type, the frequent diner's account will receive new points based only on the $80.00.
Enable this option not to add points for the portion paid with redeemed points.