(2) Level Control
①.Press      buttom to display window extension and holdoff time.
②.      Horizontal Position Knob:used to adjust the horizontal position of 
     the current channel waveform. 
③.      Horizontal Scale Knob:used to adjust the vertical scale of the current 
     waveform. The vertical scale has 1, 2, and 5 steps. 
(3) Trigger Control
① Trigger Level Knob:used to adjust the currently selected trigger level. 
② Press      to pop-up the trigger menu.
③ Press      to force generate a single trigger event .
④ Press      to display the built-in help information .
⑤ Press      to center the trigger level, trigger position, and channel position 
     simultaneously.
UTD2000CEX-II User Manual