3-3
IM DL850E-01EN
Sample Rate
If you change the time axis setting, the sample rate also changes. The sample rate is the number of samples-
per-second (S/s).
* If the sample rate is comparatively low with respect to the input signal frequency, the harmonics contained in
the signal are lost. When this happens, some of the harmonics will be misread as low-frequency waves due
to the effects described by the Nyquist sampling theorem. This phenomenon is called aliasing. You can avoid
aliasing by acquiring waveforms with the acquisition mode set to Envelope.
Aliased signal
Input signal
Sampled points
Time Axis Setting and Roll Mode Display
When the trigger mode is Auto, Auto Level, Single, or On Start and the time axis setting is 100 ms/div or longer,
instead of updating waveforms through triggering (update mode), the DL850E/DL850EV displays the waveforms
in roll mode. In roll mode, waveforms scroll from right to left as new data is captured and the oldest values are
deleted from the screen.
This allows waveforms to be observed in the same way as on a pen recorder. Roll mode is useful for observing
signals with long repeating periods and signals that change slowly. It is also effective when you want to detect
occasional glitches (pulse signals in the waveform).
You can use auto setup to automatically configure the appropriate settings (such as vertical axis, horizontal
axis, and trigger settings) for the input signal. This feature is useful when you are not sure what type of signal
will be applied to the DL850E/DL850EV. The auto setup feature will not work properly on some input signals.
Also, there are some modules with which the auto setup feature cannot be used.
Notes about Using the 16-CH Voltage Input Module (720220),
Notes about Using the 16-CH Temperature/Voltage Input Module (720221)
3 Horizontal Axis