From the manual:
Adjusting Tempo & Tweaking Delays
The Encoder can be used to set or tweak the Tempo value in BPM if Tempo is ON. To use the encoder, first press the Tap Footswitch (you must be in Play Mode) so that the Billboard displays the Tempo value in BPM. Whenever the Tap value is displayed, the Encoder can be turned to adjust the Tempo. While adjusting, the Billboard displays the updated Tempo and the parameter Control Knobs are disabled.
With Tempo OFF, the Encoder can be used to tweak delay time. To use the Encoder, first turn the Control Knob corresponding to the delay that you want to tweak; either Dly Time A or Dly Time B. Next, press the Tap Footswitch (TimeFactor must be in Play Mode) so that the Billboard displays the Delay Time value. Now turn the Encoder to adjust Delay Time. While adjusting, the Billboard displays the updated Delay Time and the parameter Control Knobs are disabled.
