HP 54645A, User'S And Service Manual

Page: 104 / 301

Recovering the waveform on the screen
In the HP 54645A/D, pressing
Run/Stop
freezes the screen. When
either of the following occur, there will be several triggers of information
on the screen.
•
The scope is running at fast sweep speeds (1
µ
s/div and faster).
For example, at 5 ns/div, the scope acquires 10 samples per trigger,
and the display record will contain many different triggers.
•
The scope is in average display mode, with averaging set to 4, 8, 16, 32, 64,
128, or 256.
The screen displays the set number of triggers averaged together,
and the acquisition data for each trigger is not maintained. Only a
screen representation exists.
In these two cases, you are still allowed to pan and zoom the waveform in
acquisition memory. However, as you first pan or zoom, you may see your
scope picture change to reflect the fact that only one trigger of acquired
data is available on which to pan and zoom. You can re-display the
original stopped screen by pressing
Setup
and
Recover Screen
.
At very slow sweep speeds of 200 ms/div and greater, if you press
Stop
, you may have two different partial acquisitions on the scope
display. One of these is the last record, and the other is the partial
newly-acquired record. If you then pan and zoom through the waveform,
the pan and zoom occurs only on the newly-acquired record, not on the
last record. Pressing
Recover Screen
here will only recover the
newly-acquired record.
MegaZoom Concepts
Recovering the waveform on the screen
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