Soak grilling planks in water for at least 1 hour.
In a food processor, combine the blackberries, wine, brown sugar, honey, hot pepper sauce, 1/8 teaspoon salt and 1/8 teaspoon pepper; cover and process until blended. Strain and discard seeds. Stir shallots and garlic into the sauce; set aside.
Place planks on grill over medium-high heat. Cover and heat until planks create a light to medium smoke and begin to crackle, about 3 minutes (this indicates planks are ready). Turn planks over.
Sprinkle salmon with remaining salt and pepper. Place on planks. Grill, covered, over medium heat for 12-15 minutes or until fish flakes easily with a fork. Serve with sauce.
