There may be several assignable knobs in the system. Each assignable knob module consists of a knob, a LCD, two range select buttons, a save button, a restore button, and an assign button.

The current knob assignment is shown on the LCD located above the knob. The first line of the display shows the Label and RefName for the assigned parameter. The second line shows the parameter value and units. The third line shows the current knob sensitivity setting.

The meter system is only accessable through the workstation it is connected to. The currently assigned control parameter in the focused window is assigned to a knob when the assign button for that meter is pushed. If the mouse control parameter is NULL, the knob is unassigned.

The knob sensitivity is given in turns to full scale (tfs). For example, if you are controlling a 15KV power supply and the sensitivity is set to 50 tfs, each complete turn of the knob will increase or decrease the voltage by 300V (15KV/50tfs = 300V). Pressing a range button increases or decreases the knob sensitivity.

The save and restore buttons work in exactly the same way as the keyboard "sv" and "rs" commands. Pressing the save button stores the current value of the parameter. Pressing the restore button recalls a previously saved value.