There are four dip switches and one push button switch on the front right hand edge of the controller board. Their use is detailed in the Switch and LED settings page, but some additional notes are here for other uses and cautions.
Switch 3, when on (down) will tell the controller that US Digital Absolute encoders are in the High Resolution mode where a full 16 bits is used instead of 12 bits. 12 bits is sufficient resolution for most usage, however.
Switch 4 cannot be left on (down) when using Absolute Encoders, it will disable their operation.