Tektronix, Inc. P6240, User Manual

Page: 67 / 321

Triggering
2–16
TLS 216 User Manual
Holdoff Holdoff
Trigger Points
Trigger Level
Holdoff
Acquisition Interval Acquisition Interval
Triggers are Not Recognized During Holdoff Time
Figure 2-2: Trigger Holdoff Time Ensures Valid Triggering
Holdoff is settable from 0% (minimum holdoff available) to 100% (maximum
available). To see how to set holdoff, see Set Mode & Holdoff on page 3–129.
The minimum and maximum holdoff varies with the horizontal scale. See the
characteristic called Holdoff, Variable, Main Trigger in the TLS Performance
Verification and Specifications shipped with the logic scope for the typical
minimum and maximum values.
Trigger Position
The adjustable trigger position defines where on the waveform record the trigger
occurs. It lets you properly align and measure data within records. The part of
the record that occurs before the trigger is the pretrigger portion. The part that
occurs after the trigger is the posttrigger portion.
To help you visualize the trigger position setting, the top part of the display has
an icon indicating where the trigger occurs in the waveform record. You use the
Horizontal menu to select what percentage of the waveform record will contain
pretrigger information.
Many users find displaying pretrigger information a valuable troubleshooting
technique. For example, when trying to find the cause of an unwanted glitch in
your test circuit, trigger on the glitch and make the pretrigger period large
enough to capture the data before the glitch. By analyzing what happened before
the glitch, you may uncover clues about its source.