HP 54620A - Page 224

Softkeys set up various options
for major functions. The softkeys
change depending on the function
you select. Some softkeys have an
immediate action, and others allow
you to scroll through a list of
choices. Some softkeys are labeled
with two choices below; the high-
lighted choice is currently active.
When several softkeys are displayed
with a labeled bar over them, they
are either related, or the choices are
mutually exclusive.
Start channel is the reference
point for a delay measurement.
Status indicators are at the top
line of the display and show chan-
nels turned off, the sampling
interval, glitch mode, delay, time
base setting, trigger condition, and
acquisition mode.
STOP indicator is displayed at
the right end of the status line when
the acquisition has been stopped.
Storage keys control start and
stop of acquisition, persistent acqui-
sition, and screen erasure.
STORE indicator is displayed at
the right end of the status line when
Autostore is selected.
Sweep speed (time base) is the
amount of time per division on the
display, and is shown on the status
line. When you vary the Time/Div set-
ting while running an acquisition, the
sample period is also being adjusted.
Thresholds define the voltage at
which there is a change from low to
high. Thresholds specified can be
TTL, CMOS, or ECL, or user-defined.
Time base See “Sweep speed.”
Trace memory is also called pixel
memory. Trace memories allow you
to save the visible portion of the ac-
quisition (the displayed waveform)
for later recall and comparison with
other measurements. Trace memory
is normally volatile. However, adding
an interface module makes the trace
memory nonvolatile. Trace memory
also saves the current configuration,
separate from the 16 setup memo-
ries.
Trigger is the point that causes
the analyzer to begin storing acquisi-
tion data. The trigger can be a signal
edge, a pattern, or a combination of
edges, patterns, occurrences, and du-
rations. See “Edge trigger,” “Pattern
trigger,” or “Advanced trigger.”
Glossary
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