To Next Page

To Previous Page

Trigger Setup

This section contains concepts and procedures for se tting up the oscilloscope to trigger on your signal.

Triggering Concepts

Trigger Event

The trigger event establishes the time-reference point in the waveform record. All waveform record data is located in time

with respect to that point. The oscilloscope continuously acquires and retains enough sample points to ﬁll the pretrigger

portion of the waveform record. That is the part of the waveform that is displayed before, or to the left of, the triggering

event on screen. When a trigger event occurs, the oscilloscope starts acquiring samples to build the posttrigger portion of

the waveform r ecord, that is, the part displayed after or to the right of the trigger event. After a trigger is recognized, the

oscilloscope will not accept another trigger until the acquisition is complete and the holdoff time has expired.

Untrigg

ered display

Trigger

ed display

Trigger Modes

The trigger mode determines how the oscilloscope behaves in the absence of a trigger event:

Normal trigger mode enables the oscilloscope to acquire a w aveform only when it is triggered. If no trigger occurs, the

last waveform record acquired remains on the display. If no last waveform exists, no waveform is displayed.

Auto trigger mode enables the oscilloscope to acquire a waveform even if a trigger does not occur. Auto m ode uses

a timer that starts when the acquisition is started, and the pretrigger information is obtained. If a trigger event is not

detected before the timer times out, the oscilloscope forces a trigger. The length of time it waits for a trigger event

depends on the time base setting.

Auto mode, when forcing triggers in the absence of valid tr iggering events, does not synchronize the waveform on the

display. The waveform w ill appear to roll across the screen. If valid triggers occur, the display will become stable.

You can also force the oscilloscope to trigger. To do so, push the front-panel Force Trig button.

64 MSO2000B and DPO2000B Series Oscilloscopes User Manual

Tektronix DPO2024B User Manual

Other manuals for Tektronix DPO2024B