Sampling Rate - HP 54710A User's Reference Manual

Acquisition Menu

Sampling Rate

Sampling Rate

Sampling rate and waveform record length (also called waveform memory)
are very closely tied together. Sampling rate determines how often the
oscilloscope samples the signal you are measuring, and waveform record
length is the amount of memory the oscilloscope must fill up before it
updates the measurement results.
Usually, you use a high sample rate, so there are plenty of data points to
better reconstruct the original waveform. For fastest throughput, you use a
short waveform record because the oscilloscope must fill up the waveform
record before it updates the measurement results. The higher the sample
rate, the faster any waveform record fills up. A long waveform record slows
down the throughput of the oscilloscope. As a result, you must often make a
trade-off between sample rate and record length, that also results in
measurement speed and accurate reconstruction of the waveform.
If you set the sample rate and record length to automatic, the oscilloscope
picks an optimum sample rate and record length that gives the best waveform
reconstruction and measurement speed for the time base scale setting you
selected. However, you may want to make the trade-off decisions yourself by
selecting a sample rate and record length that fits your application. You may
prefer to sacrifice measurement throughput by selecting a high sample rate
and a long record length, or you may want to have a high sample rate and a
short record length to maximize the measurement throughput.
There are some points you should remember when you are mixing plug-ins,
(using both single-wide plug-ins and a two-wide plug-in). The maximum
sampling rate is 2 GSa/s per plug-in slot. A two-wide plug-in, like the
HP 54721A, uses two plug-in slots which allows a maximum sampling rate of
4 GSa/s. A four-wide plug-in, like the HP 54722A, uses four plug-in slots
which allows a maximum sampling rate of 8 GSa/s. The selected sample rate
is displayed in the acquisition menu and in the status area of the screen.
(The upper left corner of the screen is the status area.)
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