Reference >> Analog Window >> Trigger When

Data Type:	int32
Description:	Specifies whether the Reference Trigger occurs when the source signal enters the window or when it leaves the window. Use Bottom and Top to specify the window.

Valid values

DAQmx_Val_EnteringWin	10163	Trigger when the signal enters the window.
DAQmx_Val_LeavingWin	10208	Trigger when the signal leaves the window.