Limit Testing
Reference
If you want to send a hardcopy command when waveform data
exceeds the limits set, toggle Hardcopy if Condition Met (side) to
ON. You can set the hardcopy system to send the hardcopy to the file
system (optional on the TDS 620A & TDS 640A). (Do not forget to
set up the hardcopy system. See

Hardcopy

on page 3-59 for details.)
If you want the bell to ring when waveform data exceeds the limits
set, toggle Ring Bell if Condition Met (side) to ON.
If you want the digitizing oscilloscope to stop when waveform data
exceeds the limits set, toggle Stop After Limit Test Condition Met
(side) to ON.
NOTE

The button labeled

Stop After Limit Test Condition Met

corre-

sponds 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.

Now that you have set up the instrument for limit testing, you must turn
limit testing on in order for any of these actions to take effect.
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 digitizing 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, more than one
waveform against a single template, or more than one waveform with each
one compared against its own template. How Limit Test operates depends on
which type of these comparisons you choose.

Single Waveform Comparisons

When making a single waveform versus a single template comparison, con-
sider 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.
Single and MultipleWaveforms