On the TPS2000+ when do I use the multipurpose knob and when do I press the bezel buttons to change settings?

On the TPS2000+ when do I use the multipurpose knob and when do I press the bezel buttons to change settings?

You use the multipurpose knob when the indicator light associated with the knob is lit (e.g., cursor position in the cursor menu). If the light is not lit, select on or off operations by pressing the bezel button (e.g., measurement type in the measure menu).