More than one axis can be controlled with the command knob on the controller. Commonly, this is because in addition to a mechanical Z-axis drive, there may also be a Piezo-Z system or a Zoom axis configured in the controller.
The Liquid Crystal Display (LCD) screen shows the current position coordinates of the axes with status information displayed to the right. The W character shows which axis is controlled by the command wheel.
The front rocker switch that engages the Z-drive clutch is also used to switch the axis controlled by the command knob. The LCD screen illustrated above shows the mechanical Z-drive clutch disengaged, and the command knob controlling the F-axis. Switching the rocker switch to the other position shows:
Where now the Z-drive is engaged and under control by the control knob.