The Sort controls allow you to change the order in which the fixtures are displayed in the Rig Data view.
The Rig Data view will not re-sort as you make changes in the Rig Data view, as this could lead to confusion. You can re-sort the view manually by clicking on the Re-Sort button. The drop-down menu allows you to specify the table column name by which the Rig Data view is sorted. The majority of columns will sort alphabetically unless the column is specifically a number (as in the Channel column). The table will sort as soon as you make a choice from the drop-down menu.