HP 54645A, User'S And Service Manual

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Acquiring Data
The HP 54645A/D operates like an analog scope, but it can do much more.
Spending a few minutes to learn some of this capability will take you a long
way toward more productive troubleshooting.
Single versus Run/Stop
The HP 54645A/D both have a Single key and a Run/Stop key. When you
press Run/Stop, the trigger processing rate is optimized over memory depth.
Single always uses the maximum memory available. When you press Single,
the oscilloscope has at least twice as much memory as when running
repetitively. Because more memory is available when using Single at slow
sweep speeds, the scope will have a greater sample rate.
When running, then pressing Stop, the oscilloscope simply stops, and several
triggers of information could be displayed on the screen. This will happen in
several cases:
•
At very fast sweep speeds (2
µ
s/div and faster), you might see less than
a full screen of data per trigger. In this case, we build a picture from
several triggers. Doing this provides a more accurate and responsive
display than mathematically interpolating between points.
•
With Average display mode on, several triggers are averaged together to
reduce noise.
•
When using Autostore, all triggers remain on the screen.
•
At very slow sweep speeds (1 s/div), part of the last trigger may still be
on the screen when you press Stop.
Run/Stop/Single/Autostore/Erase Operation
Acquiring Data
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