Agilent Technologies 24A Sprinkler User Manual


 
3-8
Triggering the Oscilloscope
To set holdoff
Holdoff Operating Hints
Holdoff keeps a trigger from occurring until after a certain amount of time has passed
since the last trigger. This feature is valuable when a waveform crosses the trigger
level multiple times during one period of the waveform.
Without holdoff, the scope could trigger on each of the crossings, producing a
confusing waveform. With holdoff set correctly, the scope always triggers on the
same crossing. The correct holdoff setting is typically slightly less than one period.
Set the holdoff to this time to generate a unique trigger point. This action works even
though many waveform periods pass between triggers, because the holdoff circuit
operates on the input signal continuously.
Changing the time base settings does not affect the holdoff number. In contrast, the
holdoff in analog oscilloscopes is a function of the time base setting, making it
necessary to re-adjust the holdoff each time you change the time base setting.
With Agilents MegaZoom technology, you can press Stop, then pan and zoom
through the data to find where it repeats. Measure this time using the cursors, then
set holdoff to this number.