Using Features for Advanced Applications
TDS 684A, TDS 744A, & TDS 784A User Manual 3–141
NOTE. The button labeled Stop After Limit Test Condition Met corresponds to the
Limit Test Condition Met menu item in the Stop After main menu. You can turn
this button on in the Limit Test Setup menu, but you cannot turn it off. In order to
turn it off, press Stop After and specify one of the other choices in the Stop After
side menu.
3. Ensure that Limit Test (side) reads ON. If it reads OFF, press Limit Test
(side) once to toggle it to ON.
When you set Limit Test to ON, the oscilloscope compares incoming
waveforms against the waveform template stored in reference memory
according to the settings in the Limit Test Sources side menu.
You can compare a single waveform against a single template. When making a
single waveform versus a single template comparison, consider the following
operating characteristics:
The waveform will be repositioned horizontally to move the first sample in
the waveform record that is outside of template limits to center screen.
The position of the waveform template will track that of the waveform.
You can also compare more than one waveform against a single template, or
more than one waveform with each one compared against its own template or a
common template. When setting up for such comparisons, consider the following
operating characteristics:
You should set Horizontal Lock to None in the Zoom side menu (push
ZOOM and press (repeatedly) Horizontal Lock to None). See Zoom a
Waveform, on page 3–38 for more information on horizontal lock.
With horizontal lock set as just described, the oscilloscope will reposition
each waveform horizontally to move the first sample in the waveform record
that is outside of template limits to center screen.
If you are comparing each waveform to its own template, the position of
each waveform template will track that of its waveform.
If you are comparing two or more waveforms to a common template, that
template will track the position of the failed waveform. If more than one
waveform fails during the same acquisition, the template will track the
position of the waveform in the highest numbered channel. For example,
CH 2 is higher than CH 1.
Single WaveformComparisonsMultiple WaveformComparisons