Tektronix TDS3000C Series User Manual page 91

TDS3000C Series Oscilloscope User Manual
Horizontal Zoom and Preview. There are two ways you can magnify a stopped
acquisition, horizontal zoom or preview. The differences in how horizontal zoom
and preview interact with other functions are shown in the next table.
Function
Horizontal Scale
Horizontal Position
Delay button
Math waveform
Cursors and automatic
measurements
Gray-scale
Slow Horizontal Settings. At horizontal Scale settings of 40 ms/div or slower,
the oscilloscope may display waveforms in roll mode. As the rolling waveform
fills the screen, the waveform intensity and vector fill appears to decrease. The
oscilloscope automatically reduces the number of displayed points in order to
maintain a high acquisition rate: this does not represent a loss of acquired data.
When you stop the acquisition, the original waveform intensity and vector fill
returns to the display.
Using Zoom and Delay Together. You can use both zoom and delay at the same
time to magnify a delayed acquisition.
Fast Time-Base Settings. At the fastest time-base settings, only a portion of the
waveform shows in the display. The waveform record icon indicates that portion
with brackets. Push the zoom
control to scroll through the entire waveform to see any portion you want. The
affected time-base settings are shown in the next table.
Acquisition resolution
Normal
Fast Trigger
At the fastest time-base settings, the maximum zoom magnification factor is also
reduced.
Delay Interactions. The maximum delay setting is a function of the time-base
setting and acquisition resolution. If you set a large positive or negative delay,
Horizontal zoom
Sets magnification factor
Selects portion of waveform
to magnify
Turns delay on and off
Remains valid; magnifies
and positions with other
waveforms
Remain functional with valid
readouts
Gray-scale information may
be temporarily reduced
button and then use the horizontal Position
Affected time-base settings
100 ns/div to 1 ns/div
4 ns/div to 1 ns/div
Reference
Horizontal preview
Changes time base for the
next acquisition
Changes trigger position
or delay time for the next
acquisition
Turns delay on and off
Remains fixed; does not
track changes to channel
waveforms
Remain locked to channel
waveforms
Gray-scale information is
lost
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