In mixing bowl, beat sugar and butter until light and fluffy, stopping to scrap bowl occasionally. Beat in eggs, 1 at a time until blended. Add zest and juice. In small bowl, whisk together flour, salt, baking powder and baking soda to blend well. On low speed, add flour mixture, in three parts, alternately with buttermilk, in two parts. Mix just until blended, stopping to scrap bowl often. Batter will be very thick. Spoon batter onto hot, greased waffler and bake.