Tektronix CSA8000B Series, User Manual

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Acquiring Waveforms
3- 20
CSA8000B & TDS8000B User Manual
NOTE
. Resolution and the equivalent elements, sample interval and sample rate
(see equation 3 above), are not settable directly, but are derived. You can,
however, check the resolution at anytime in the resolution readout (push the
Horizontal Menu button). Also note, that the Resolution knob actually adjusts
the record length to increase sample density (detail).
Independent vs. Shared Window. For a given time base, the instrument applies the
same horizontal acquisition window to all channels from which it acquires data.
Unlike the vertical acquisition window that you set independently for each
channel, the same time/division, resolution (record length), and horizontal delay
(from the same trigger point) that you set for a time base, apply to all channels in
that time base. In other words, one trigger, from a single trigger source, will
locate a common horizontal acquisition window on all active channels, which
you can shift by setting the horizontal position control.
The horizontal acquisition window determines the waveform records extracted
from all signals present at all active channels and math waveforms. You can
think of the horizontal acquisition window as cutting across any input signals
present in the input channels to extract the same slice of time into waveform
records. See Figure 3--5.
Ch4 record
Ch3 record
Ch2 record
Ch1 record
Common horizontal
delay
Common trigger
Common record start
point and record length
Figure 3- 5: Common trigger, record length, and acquisition rate for all channels