HP 54645A, User'S And Service Manual

Page: 280 / 301

Glossary
This glossary is organized into
two parts: logic and scope terms.
Logic terms apply only to the
HP 54645D MSO (Mixed-Signal
Oscilloscope), and scope terms
apply to both the HP 54645A/D
Oscilloscopes.
HP 54645D Logic Terms
Acquisition is the process by
which the MSO collects data. The os-
cilloscope acquires data by sampling
the voltage on each analog and digi-
tal input channel and comparing it to
the trigger condition. In Normal trig-
ger mode, the oscilloscope begins
filling the pre-trigger buffer with
data. When that buffer is full, the os-
cilloscope will begin searching for
the trigger event. In Auto trigger
mode, the oscilloscope fills the pre-
trigger buffer, then searches for the
trigger event for a predetermined in-
terval.
Acquisition memory depth is 2M
when only one pod is active and the
sampling speed is 400 MSa/s. When
both pods are active, the sampling
speed is reduced to 200 MSa/s and
the memory depth is reduced to 1M.
Acquisition memory is located in the
acquisition subsystem sample RAM.
Advanced trigger consists of two
pattern and two edge sources com-
bined with a variety of operators to
form the complete Advanced trigger
specification. Advanced trigger is
best used when the events you want
to capture are defined by a complex
series of waveform events in the sys-
tem, and neither pattern mode nor
edge mode are capable of clearly re-
solving the necessary sequence.
Channel controls allow you to
move or rearrange channels, turn
them on or off, and add descriptive
labels.
Duration is the time or signal
width measured using the advanced
pattern and glitch triggers. In an ad-
vanced pattern and glitch triggers,
you can set the minimum duration
by pressing a softkey or rotating the
Entry knob.
Duration trigger operators
in
advanced pattern and glitch triggers,
you can specify a duration on which
the oscilloscope should trigger. Dura-
tion greater-than and less-than
operators are available, and are valid
when only pattern terms are in-
volved, and are not selectable when
any edge terms are selected as a
source.
Glossary-1