HP 54710A User's Reference Manual page 301

Trigger Menu
Holdoff and Conditioning
Holdoff
After the oscilloscope triggers, it waits an amount of time set by holdoff
before rearming the trigger circuit. When the trigger circuit is rearmed, it
can then accept the next trigger. You can specify an amount of holdoff from
60 ns to 320 ms. Use holdoff to synchronize a waveform to a trigger signal.
Holdoff is used to stabilize the display of complex waveforms, or to trigger on
a burst of pulses that are separated by time and you want to trigger at the
start of the pulse burst. Figure 18-8 shows a pulse burst with the holdoff
time represented as T . You may notice that holdoff keeps the trigger circuit
1
from rearming until after the pulse burst is over. That way, the first pulse in
the next burst is the trigger event.
The advantage of digital holdoff is that it is a fixed number. As a result,
changing the time base settings does not affect the holdoff number and the
oscilloscope remains triggered. In contrast, the holdoff in analog
oscilloscopes is a function of the time base setting making it necessary to
readjust the holdoff each time you change the time base setting.
Holdoff
Figure 18-8
Holdoff keeps the trigger circuit from rearming for time T
1
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