Technical data

Advanced Triggering, Search & Navigation, and Segmented Acquisition Labs 3
4000 X-Series Oscilloscopes Advanced Training Guide 55
Looking at the on- screen Rise Time measurement statistics, we can see
that the scope is measuring a minimum Rise Time in the range of 50 ns,
while also measuring a maximum Rise Time in the range of 125 ns as
shown in Figure 32. If we assume that our system specification requires
that signal edge speeds (based on 10% to 90% threshold levels) must be
faster than 100 ns, then we have just detected a signal integrity problem
with our design. To further troubleshoot this issue we should set up our
scope to uniquely trigger on just the edges that are in violation. This might
help us isolate what the root cause might be that is causing these
occasional violations. Uniquely triggering on edge speed violation signals
can be accomplished on Agilent’s 4000 X- Series oscilloscopes using the
Rise/Fall Time triggering mode.
11 Press the [Trigger] front panel key and select the Rise/Fall Time trigger
type.
12 Press the Level Select softkey to select Low.
13 Turn the Trigger Level knob to set the lower trigger threshold level to the
approximate 10% level. Note that you can also drag the T
L
marker on
the left edge of the display.
Figure 32 The scope’s measurement statistics shows the range of rising edge speeds on
this signal.