User manual

WaveSurfer 3000 Oscilloscopes
Trigger
While the oscilloscope is continuously sampling signal when it is turned on, it can only display up to its
maximum memory in data samples. Triggers select an exact event/time in the waveform to display on the
oscilloscope screen so that memory is not wasted on insignificant periods of the signal. For all trigger types,
you can set:
l Pre-trigger or post-trigger delay—time relative to the trigger event displayed on screen (although the
trigger itself may not be visible).
l Time between sweeps—how often the display is refreshed.
Unless modified by a pre- or post-trigger delay, the trigger event occurs at point zero at the center of the grid,
and an equal period of time before and after this point is shown to the left and right of it.
In addition to the trigger type, the trigger mode determines how the oscilloscope behaves in the presence or
absence of a trigger event.
Trigger Modes
The trigger mode determines how the oscilloscope sweeps, or refreshes, the display. This can be set from
the Trigger menu or from the front panel Trigger control group.
Auto mode causes the oscilloscope to sweep without a set trigger. An internal timer triggers the sweep after
a preset timeout period so that the display refreshes continuously. Otherwise, Auto functions the same as
Normal when a trigger condition is found.
In Normal mode, the oscilloscope sweeps only if the input signal reaches the set trigger point. Otherwise it
continues to display the last acquired waveform.
In Single mode, one sweep occurs each time you choose Trigger >Single or press the front panel Single
button.
Stop pauses sweeps until you select one of the other three modes.
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