Advanced Triggering, Search & Navigation, and Segmented Acquisition Labs
3
3000 X-Series Oscilloscopes Advanced Training Guide
45
sometimes triggers on later pulses within this burst. We could further
stabilize triggering on the 1st pulse in this burst if we used the scope’s
trigger holdoff capability. But what if we wanted to trigger on a specific
pulse (other than the 1st pulse)? We could accomplish this by using the
“Nth Edge Burst” triggering mode, assuming that the input signal is a
repetitive burst. We will show how to use the “Nth Edge Burst” triggering
mode in the next lab (Lab #9). Another option would be to use the scope’s
“Pulse Width” triggering mode, which can be used on a continuous data
stream of digital pulses; the data stream does not need to come in bursts.
But the pulses must have a unique pulse width for this triggering mode to
be effective. Note that the 5th pulse within this burst has a positive pulse
width of approximately 300 ns. This is a unique pulse width within this
burst of pulses. Let’s now set up the scope to trigger specifically on this
pulse.
9
Press the
[Trigger]
front panel key; then select the
Pulse Width
trigger
type using the Entry knob.
10
Press the “
< > ><
” softkey; then select the “
><
” time qualifier.
11
Press the “
< 30 ns
” softkey; then set the time to
< 350 ns
using the
Entry knob.
12
Press the “
> 20 ns
” softkey; then set the time to
> 250 ns
using the
Entry knob.
13
Set the scope’s timebase to
500.0 ns/div
.
Figure 26 Triggering on a 300 ns wide pulse using the scope’s Pulse Width triggering
mode.