46
3000 X-Series Oscilloscopes Advanced Training Guide
3
Advanced Triggering, Search & Navigation, and Segmented Acquisition Labs
Your scope should now be triggering at the end of the 5th pulse of the
burst as shown in
. This particular pulse uniquely meets the
pulse width time qualification of > 250 ns, but < 350 ns. You can select
the
+Width
measurement if you would like to verify that this pulse has an
approximate width of 300 ns.
Now take note of the narrow infrequent glitch that occurs after the end of
this burst of six pulses. In addition to using the scope’s Pulse Width
trigger type to trigger on “known” pulses that have unique widths, such as
this 300 ns wide pulse, we can also use the Pulse Width triggering mode
to trigger on “unknown” or “unwanted” glitches. Let’s do it.
14
Press the “
< > ><
” softkey; then select the “
<
” time qualifier.
15
Press the
< 30 ns
softkey; then set the time to
< 50 ns
.
Your scope should now be triggering on the narrow infrequent glitch that
follows the repetitive burst of six pulses as shown in
. Note that
if this glitch was more infrequent, you would also need to select the
Normal
trigger mode to avoid auto triggering.
Let’s now use the scope’s Segmented Memory mode of acquisition to
capture 500 consecutive occurrences of this burst of pulses to see if we
can determine how often the glitch occurs relative to the occurrence of
each burst. But before beginning a Segmented Memory acquisition, we will
Figure 27 Triggering on a narrow infrequent glitch using the scope’s Pulse Width
triggering mode.