Agilent Technologies DSO-X 4022A, User Manual

Page: 227 / 488

Acquisition Control
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Agilent InfiniiVision 4000 X-Series Oscilloscopes User's Guide 227
• If you press the [Stop] key, and pan and zoom through the waveform
using the Horizontal and Vertical controls, only the last trigger's
acquisition will be displayed.
When Realtime sampling is off (equivalent time mode):
• Instead of the reconstruction filter, a technique known as random
repetitive sampling is used to build- up and draw one waveform using
multiple triggers (acquisitions).
• Equivalent time sampling mode requires a repetitive waveform with a
stable trigger.
See Also
• "Realtime Sampling and Oscilloscope Bandwidth" on page 227
Realtime Sampling and Oscilloscope Bandwidth
To accurately reproduce a sampled waveform, the sample rate should be at
least 2.5 times the highest frequency component of the waveform. If not, it
is possible for the reconstructed waveform to be distorted or aliased.
Aliasing is most commonly seen as jitter on fast edges.
The maximum sample rate for the 4000 X- Series oscilloscopes is 5 GSa/s
for a single channel in a channel pair. Channels 1 and 2 constitute a
channel pair, and channels 3 and 4 constitute another channel pair. For
example, the sample rate of a 4- channel oscilloscope is 5 GSa/s when
channels 1 and 3, 1 and 4, 2 and 3, or 2 and 4 are on.
Whenever both channels in a channel pair are on, the sample rate for all
channels is halved. For example, when channels 1, 2, and 3 are on, the
sample rate for all channels is 2.5 GSa/s.
When Realtime sampling is on, the bandwidth of the oscilloscope is
limited because the bandwidth of the reconstruction filter is set to fs/4.
For example, a MSOX410xA oscilloscope with channels 1 and 2 on has a
bandwidth of 625 MHz when Realtime sampling on and 1 GHz when
Realtime sampling is off.
The sample rate is displayed in the sidebar Summary dialog.