# Knob Dialog Operations

To access the Knob Dialog box shown in Figure 6-28, double-click on the Knob icon. Variables which are eligible for assignment to the Knob appear in the Allowable list (items which appear to be "grayed out" have already been assigned to another input device or have non-constant values). Double-click on the variable name in the allowable column you wish to assign to the Knob or select the item and click on the >> button to move it to the Selected list.

Once a variable has been selected, Min and Max fields will appear. You can set the display range for the Knob by entering values in these fields. The Increment pop-up menu allows you to set the increments between values that can be selected on the Knob. Click-and-hold on the down-arrow to view the Increment options.

Figure 6-28 Knob Dialog Box

Other display options for the Knob include Show Nav Arrow and Show Name. Showing the navigation arrow will put a small arrow on the Knob which, when clicked, will navigate a user to the associated variable in the Map/Model level. If Show Name is checked, the variable name will be displayed. Figure 6-27 shows an example of an assigned Knob with name and navigation button both displayed.

When a user changes the value of a variable associated with a Knob by moving the dial, a small "U" button appears in the lower left corner. To restore the Knob to its original value, click once on the "U" button (to undo).

Note: When a variable has been assigned to a Knob, a Knob icon appears on that variable at the model level. This makes the author and model users aware that the variable's value is being set at the Interface level, and not in the entity's dialog box.