HP 54710A User's Reference Manual page 289

Trigger Menu
Mode
Pattern
Pattern allows you to have the oscilloscope search for a pattern that you
define. You can define a pattern using any channel or external trigger, up to
a four bit wide pattern. After recognizing the pattern, the oscilloscope
triggers. The pattern is defined as L = low, X = don't care, and H = high. A
high is a voltage above the trigger level, and a low is a voltage below the
trigger level.
Pattern Defines a 4-bit pattern that the oscilloscope searches for. The
numbers correspond to the plug-in slots. If a slot is empty, that slot
number does not appear as part of the pattern. Two-wide plug-ins, like
the HP 54721A, take up two slots. For example, if the two-wide plug-in
is installed in slots one and two, the channel connector is slot 1 and the
external trigger connector is slot 2.
You can also set the trigger level independently on each slot. For example,
you can set the trigger level on channel 1 to a TTL high and channel 2 to an
ECL low.
When Selects when the trigger is to occur. The choices are listed below.
•
Entering a pattern, the trigger occurs on the edge of the source that is the
last edge to make the pattern true.
•
Exiting a pattern, the trigger occurs on the edge of the source that is the
first edge to make the pattern false.
•
A pattern is present greater than a defined time. A timer starts when the
pattern is entered. If the pattern is present greater than the specified
time, the trigger occurs when the pattern is exited.
•
A pattern is present less than a defined time. A timer starts when the
pattern is entered. If the pattern is present less than the specified time,
the trigger occurs when the pattern is exited.
•
A range of time. (When a pattern is present greater than a defined time
and less than another defined time.) A timer starts when the pattern is
entered. If the pattern is present greater than one specified time and less
than another specified time, the trigger occurs when the pattern is exited.
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