Chapter 10 Ladder Diagram Function block definitions can be dragged, but function block instances cannot be dragged. Method 2 Click the position in which an applied instruction or a function block will be inserted, click select the item which will be inserted in the API/FB window, and click Insert . on the toolbar, Users can select the All Types option button, the Comparison Instruction option button, the API option button, or the Function Block option button. If users select the API option button in the Type Class section, they have to select an instruction type in the Classification box. 10-15