Teledyne Lecroy WaveSurfer 3000, Руководство оператора, Страница: 40 / 97

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:
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Pre-trigger or post-trigger delay—time relative to the trigger event displayed on screen (although the trigger itself
may not be visible).
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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 capabilities include:
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Simple Triggers activated by basic waveform features such as an edge with a positive or negative slope or width.
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Pattern Triggers that fire when a pattern condition occurs on selected input channels.
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SMART Triggers , sophisticated triggers that enable you to create basic or complex trigger conditions. Use SMART
Triggers for signals with rare features, like glitches.
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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