SIGLENT SDS1000CML+, User Manual, Page: 63 / 159

SIGLENT
SDS/SD User Manual
53
When you push the RUN/STOP or SINGLE buttons to start an acquisition, the
oscilloscope goes through the following steps:
1
）
. Acquire enough data to fill the portion of the waveform record to the left of
the trigger point. This is also called the pre-trigger.
2
）
. Continue to acquire data while waiting for the trigger condition to occur.
3
）
. Detect the trigger condition.
4
）
. Continue to acquire data until the waveform record is full.
5
）
. Display the newly-acquired waveform.
■ Time Base: The oscilloscope digitizes waveforms by acquiring the value of an
input signal at discrete points. The time base allows you to control how often the
values are digitized.
Use S/div knob to adjust the time base to a horizontal scale suits your purpose,
■ Time Domain Aliasing
：
Aliasing occurs when the oscilloscope does not sample the signal fast enough to
construct an accurate waveform record. When this happens, the oscilloscope
displays a waveform with a frequency lower than the actual input waveform, or
triggers and displays an unstable waveform.
Sampled points
Apparent low-frequency
waveform due to aliasing
Actual high-frequency waveform
Picture 2.9-5