User`s guide

173
Using the Oscilloscope
The Scope Trigger Menu
The pattern duration time can be any value between 20 ns and 160 ms
in 10 ns steps.
If the count set in the Count field is one, the trigger event will be the
first pattern event that meets both the pattern specification and the
duration specification. If the count is greater than one, only the first
pattern event must meet the duration specification. Once the pattern
duration specification has been met, subsequent pattern events that
meet the pattern specification can be of any duration and each such
pattern event will contribute to meeting the count specification. For
instance, with a pattern specification of HX, a duration specification of
>100 ns, and a count of 3, a pulse string with pulse widths 80 ns, 150
ns, 50 ns, 75 ns, 20 ns, 200 ns would trigger on the trailing edge of the
75 ns pulse. In this example, the 150 ns pulse meets the duration
specification and is count 1, the 50 ns pulse is count 2, and the 75 ns
pulse is count 3.
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 less than the time duration specified. If the pattern
specification remains true after the specified duration time has
elapsed, the search for a trigger condition starts again the next time
the pattern specification becomes true. If the pattern specification
becomes false before the specified duration time, the trigger point will
be the point at which the pattern specification becomes false.
The pattern duration time can be any value between 20 ns and 160 ms
in 10 ns steps.