HP 54645A, User'S And Service Manual

Page: 61 / 301

Triggering HP 54645A/D Oscilloscopes
The HP 54645A/D Oscilloscopes provide a full set of features to help
automate your measurement tasks, including MegaZoom technology
to help you capture and examine the stored waveforms of interest,
even untriggered waveforms. With these oscilloscopes you can:
•
Modify the way the oscilloscope acquires data.
•
Set up simple or complex trigger conditions, as needed, to capture
only the sequence of events you want to examine.
The HP 54645A and HP 54645D have common triggering functionality:
•
Trigger modes (Auto Lvl, Auto, Normal)
•
Line triggering
•
Glitch triggering
•
TV triggering
•
Mode/Coupling (including frequency and noise rejection—see
chapter 5)
•
Holdoff and Trigger Level
•
Slope/Edge Triggering
This chapter explains how to do all these things and more. If you are
not familiar with basic operations, see chapter 1, “Getting Started.”
See also “Triggering the HP 54645D Mixed-Signal Oscilloscope” in this
chapter for additional triggering functionality.
Glitch Trigger
In digital system design, a
glitch
is an unintentional or unexpected
signal transition, which may or may not pass through the logic
threshold.
The advanced glitch trigger menu lets you select the analog (A1 or A2
on HP 54645D) or digital (D0-D15 on HP 54645D) channel on which
to capture a glitch event. You specify the polarity and duration
qualifier—either less than (<), greater than (>), or a range—for the
glitch. The HP 54645D can capture glitches >8 nanoseconds and
<100 seconds.
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