YOKOGAWA DL850E User Manual page 40

Horizontal Axis (Time Axis)
Time Axis Setting
Normally, under the initial settings, the time axis scale is set as a length of time per grid division (1 div).
The selectable range is 100 ns/div to 20 days/div. As you adjust the value, the unit changes between
seconds, minutes, hours, and days automatically. Because the horizontal display range is 10 div, the
amount of time on the waveform that is displayed is equal to the time axis setting × 10.
* If a 720210 (HS100M12) or 720211 (HS100M12) module is installed, the lowest setting is 100 ns/div.
Otherwise, it is 1 μs/div.
Internal and External Clocks (Time base selection)
Under the initial settings, the DL850E/DL850EV samples the measured signal using the internal clock
signal produced by its internal time-base circuit.
You can also use an external clock signal to control sampling. Apply the external clock signal to the
external clock input terminal. This external clock input is useful for synchronizing to the clock signal of
the waveform that is being measured.
Relationship between the Time Axis Setting, Record Length, and
Sample Rate
If you change the time axis setting, the sample rate and the acquisition-memory record length also
change. For details, see appendix 1.
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). When the sample rate is low compared to the frequency of the input
signal, the high-frequency components of the waveform are misread as low-frequency components.
To prevent the high-frequency components from being misread, sample the signal at the highest
sample rate possible, or set the waveform acquisition mode to Envelope.
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.
IM DL850E-03EN
2.1 Vertical and Horizontal Axes
1
2
3
4
5
6
App
Index
2-3