TDS 684A, TDS 744A, & TDS 784A User Manual 3–137
Using Features for Advanced Applications
The TDS Oscilloscope provides powerful features for testing and digitally proces-
sing the waveforms you acquire. This section describes how to use the following
features:
Limit Testing — for testing the waveforms you acquire against a template
you create (on this page)
Waveform Math — for inverting, adding, subtracting, and multiplying of
waveforms (see page 3–142)
Fast Fourier Transforms for displaying the frequency content of
waveforms (see page 3–144)
Waveform Differentiation for displaying the derivative of a waveform
(see page 3–161)
Waveform Integration for displaying the integral of a waveform (see
page 3–165)
NOTE. If InstaVu mode is on, the features listed above are not available; press
InstaVu on the front panel to toggle InstaVu mode off.

Limit Testing

The TDS Oscilloscope provides limit testing, which can automatically compare each
incoming or math waveform against a template waveform. You set an envelope of
limits around a waveform and the oscilloscope finds waveforms that fall outside
those limits. (See Figure 3–82.) When it finds such a waveform, the oscilloscope
can generate a hardcopy, ring a bell, and stop and wait for your input.
Figure 3–82: Comparing a Waveform to a Limit Template