When Field - HP 16534A User Reference

To enter a pattern, touch either X, L, or H on the pop-up keypad. The entries
you make appear at the top of the pop-up keypad as they are entered. If you
make a mistake, turn the knob to move the highlight to the entry to be
corrected and select the correct entry, or touch CLEAR to change all entries
back to X and enter the correct values. If the pattern is correct, touch
DONE.
A pattern of XXX says to use NO channels to find the trigger. It does not equate
to Immediate Mode when Auto-Trig is set to Off. This event will never occur in
the hardware. Do not confuse XXX with "don't care, trigger on anything."

When Field

When you touch this field, a pop-up menu appears that lets you specify the
trigger When condition.
Pattern Trigger When Condition Pop-up Menu
The Pattern When pop-up menu is used to specify the trigger when condition
for pattern triggering. Once a selection has been made, you touch the Done
field to exit the pop-up menu and return to the trigger menu. The trigger
condition selected will now appear in the When field.
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.
The Trigger Menu
When Field
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