User`s guide

172
Using the Oscilloscope
The Scope Trigger Menu
When field
The When field appears only when Pattern mode is selected. When you
select this field, a pop-up menu appears that lets you specify the
trigger When condition.
Pattern When condition pop-up menu
The Pattern When pop-up menu is used to specify the trigger-when
condition for pattern triggering. The default selection for the When
field is When Entered.
When Entered. When this field is active, the oscilloscope triggers on
the first transition that makes the pattern specification true for every
input used in the pattern trigger specification. If the count set in the
Count field is more than 1, the pattern must be true for the number of
times set in the count field.
When Exited. When this field is active, the oscilloscope triggers on
the first transition that causes the pattern specification to be false for
every input used in the pattern trigger specification. If the count set in
the Count field is more than 1, the pattern must be true for the number
of times set in the count field before turning false.
Present >. When this field is active, the scope triggers on the first
transition that causes the pattern specification to be false for any input
used in the pattern trigger specification if the specified pattern has
been true for the time duration specified. If the pattern specification
becomes false before the specified duration time has elapsed, the
search for a trigger condition starts again. If the pattern specification
remains true longer than the specified duration time, the trigger point
will be the point at which the pattern specification becomes false.