Memory Depth; Chapter 5 Trigger System Settings; Trigger System Interpretation - UNI-T UPO3000E Series User Manual

4.3 Memory Depth

The memory depth refers to the number of waveform points that the
oscilloscope can store in one trigger acquisition. It reflects the storage capacity
of the acquisition.
Memory depth, sampling rate and wavelength should meet the following
formula:
Memory depth = Sampling rate × Horizontal time base × Horizontal grids
UPO3000E comes with 70Mpts memory depth (per channel). Press
ACQUIRE Memory depth to set the memory depth to automatic, 7k, 70k,
700k, 7M or 70M. The default is automatic.

Chapter 5 Trigger System Settings

Trigger determines when the oscilloscope starts to collect data and display
waveform. Once the trigger is correctly set, it can convert unstable signals
into meaningful waveforms. In the beginning of data acquisition, it first
collects enough data to plot a waveform on the left of the trigger point, and
continuously collects data while waiting for the trigger. When a trigger is
detected, the device continuously acquires enough data for plotting a
waveform to the right of the trigger point.
In this chapter, the 4-channel UPO3XX4CS will be used as an example.

5.1 Trigger System Interpretation

(1) Trigger Source
A signal for generating a trigger. Triggers can be obtained from a variety of
sources such as input channels (CH1, CH2, CH3, CH4), external trigger
(EXT, EXT/5), AC Line, etc.
Input Channel: Select any one of the analog signal input terminal
CH1~CH4 on the front panel of the oscilloscope as a trigger signal.
External Trigger: Select the EXT Trig (EXT or EXT /5 input terminal)
input signal from the back of the oscilloscope as a trigger signal.
For example, the external clock input can be used on the EXT Trig
terminal as a trigger source, including EXT and EXT/5. EXT trigger
level ranges from -1.8V ~ +1.8V can be set. EXT/5 trigger level range
is increased to -9V ~ +9V.
AC Line: Power supply. It can be used to observe signals related to mains,
such as relationship between lighting equipment and power supply
equipment, so as to achieve stable synchronization.
(2) Trigger Mode
Trigger mode determines the behavior of the oscilloscope during a trigger
event. This oscilloscope provides three kinds of trigger modes: auto, normal,
and single trigger. Press the MODE on the trigger control area to switch the
trigger modes.
Auto trigger: When there is no trigger signal, the system automatically
runs and displays data. When the trigger signal is generated, it automatically
switches to trigger scanning to synchronize with the signal.
Note: This mode allows 40ms/div or slower time scale without triggering in
ROLL mode.
Normal Trigger: The oscilloscope only collects data when the trigger
condition is satisfied. When it is not triggered, the oscilloscope will stop data
acquisition and wait for the trigger signal.
Single Trigger: Press once the SINGLE key and the oscilloscope will wait
for the trigger. When the instrument detects a trigger, the waveform is sampled
and displayed, and enters the STOP state. Press the SINGLE button on the
front panel of the oscilloscope to quickly enter the single trigger mode.
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