Holdoff

In the Trigger tab controls, select the Holdoff subtab to view its controls.

• Mode — There are two options for the holdoff :

  • Fixed — The Fixed trigger holdoff mode can be used to stabilize the display of complex waveforms. The Holdoff Time control sets the amount of time that the oscilloscope waits before re-arming the trigger circuitry. For example, if you have a burst of pulses and want to trigger on the first pulse in the burst, you can set the holdoff time to be slightly longer than the burst width.

    

  • Random — This mode varies the trigger holdoff from one acquisition to another by randomizing the time value between triggers. The randomized time values can be between the values specified in the Min holdoff time and Max holdoff time fields that appear when Random mode is selected.

    This mode ensures that the oscilloscope re-arms after each acquisition in a manner that minimizes or eliminates the likelihood of triggering at the beginning of a DDR burst. Randomizing the holdoff increases the likelihood that the oscilloscope will trigger on different data phases of a multi-phase (8 data transfer) burst. This mode mixes up the traffic pattern the oscilloscope triggers on and is very effective when used on repeating patterns.