HP 16533A, User Reference, Page: 73 / 152

Slope Field
You can set the trigger slope to trigger on either the positive or negative edge
of the trigger source waveform. When you touch the Slope field, the field
toggles between Positive and Negative.
The default selection for the Slope field is Positive.
Count Field
In edge trigger mode, you can define a positive or negative edge and the
trigger level as a trigger qualifier. When the oscilloscope detects the trigger
qualifier, it will trigger at a user-specified number of edges (Count field) on
the waveform.
The Count field defines the number of trigger events that must occur after
the first trigger qualifier before the oscilloscope will trigger and acquire a
waveform.
Count can be set to any integer from 1 to 32,000. When the Count field is
selected, the trigger events count can be changed by turning the knob or by
entering a value from the pop-up keypad.
This type of triggering is commonly referred to as "events triggering" or
"delay-by-events triggering". It is very useful when trying to trigger on a
specific pulse in a burst of pulses, with a long time delay, before the next
burst occurs.
The default value for the Count field is 1.
The Trigger Menu
Slope Field
6-9