5-3
IM DL35-01EN
How the Time Axis Relates to the Display of the Waveform
There are 10 div along the time axis, and 1001 points (logical number of points, not the dots on the screen) are
used to draw the waveforms. As such, if the display record length is greater than or equal to 2 kpoint, as shown
in the figure on the right, the instrument draws the waveform by determining the maximum and minimum values
at each fixed interval (P-P compression) and aligning them vertically at the same time position (total number of
points: 2002).
1001 points*
0
1000
Sampled data
Time axis
Record length
<P-P compression display>
Maximum value
Minimum value
* 1001 is the logical number of
points. On the screen, the data
is compressed to 800 or 500
dots (1000 dots in the
full-screen waveform display).
Vertical axis
Zooming Horizontally and Drawing Waveforms
The instrument can expand (zoom) the waveform horizontally. When the zoom factor of the waveform is
increased, the number of displayed points decreases. The instrument displays the waveform using P-P
compressed until the number of displayed points falls to 2002, but it cannot display the waveform using
continuous lines when the number of displayed points falls below 1001. When this happens, the instrument
data so that the number of displayed points is 1001.
Dot Display
Under the initial settings, display interpolation is performed automatically, but you can also disable display
interpolation (set it to OFF) and display the waveform using dots. When interpolation is disabled, up to 2001
points or 100001 points (2 kpoint or 100 kpoint, whichever is selected) of all the acquired data are displayed
without P-P compression. For example, if the number of displayed points is set to 100 kpoint and the display
record length is 10 kpoint (the number of acquired data points is 10001 points), the instrument draws all the
points of the waveform by aligning 10 points vertically at the same time axis position. If the number of acquired
data points exceeds 2001 or 100001, to display the waveform, the instrument reduces the amount of data to
2001 or 100001 points (2 kpoint or 100 kpoint, whichever is selected) by removing the data between displayed
points.
Relationship between the Time Scale, Record Length, and Sample Rate
When you change the time scale, the sample rate and record length also change. For details, see appendix
1, “Relationship between the Time Scale, Record Length, and Sample Rate” in the
Getting Started Guide
, IM
DL350-03EN.
5 Waveform Acquisition