:TRIGger SEQuence Window Commands
The Window trigger mode lets you specify a voltage range and then trigger when the waveform either exits this range, enters this range, stays outside the range for too long or too short a time, or stays inside the range for too long or too short a time.
Use the :TRIGger:CHANnel:LTHReshold command to set the lower level of the voltage range.
Use the :TRIGger:CHANnel:HTHReshold command to set the upper level of the voltage range.