====Filter wheel ====
* Select the filterwheel tab. There may be one or two wheels physically present; the interfaces to these are displayed side-by-side. The interface values for a wheel will be empty if the wheel is absent.
* Initialize the wheel by clicking the "Initialize" button (usually only at the start of the night, but may also be done if you suspect that the controller has lost its way). The wheel will move around to the reference position; this may take several seconds. While still moving, the "Moving" indicator above the controls will be red. Once there, the "Initialized" and "At Ref" indicators should turn green. The value in the "Current Position" field should be 1 after initialization. '''YOU MUST INITIALIZE BOTH FILTER WHEELS AT THE START OF THE NIGHT, AND MOVE ONE TO AN "EMPTY" POSITION TO ENSURE THAT THE CORRECT FILTERS ARE FILTER IS IN THE BEAM.'''
* Select the filter required, by using the up and down arrows on the right of the "Required Position" field. The filter name will indicate the filter in the selected position. Click the "Move" button. The indicators above the wheel controls should change; once the wheel has reached the required position, the "Moving" indicator should turn grey, while the "Centred" indicator should be green. The "Current Position" field will indicate the slot number and name of the filter now in the light path.