Missing Pulses - Fluke ScopeMeter 190 Series III User Manual

190 Series III
Users Manual

Missing Pulses

The next example is about how to find missing pulses in a train of positive pulses. In this
example, it is assumed that the pulses have a 100 ms distance between the rising edges. If the
time accidentally increases to 200 ms, a pulse is missing.
To set the test tool to trigger on such missing pulses, let it trigger on gaps bigger than 110 ms:
T
1. Press
2. Press 4 to open the TRIGGER OPTIONS menu.
3. Use the cursor and E to select Pulse Width on A and open the TRIGGER ON PULSE
WIDTH menu.
4. Use the cursor and E to select the positive pulse icon to trigger on a positive pulse, then
jump to Condition.
5. Use the cursor and E to select >t and jump to Update.
6. Use the cursor and E to select On Trigger and exit the menu.
The test tool is now prepared to trigger on pulses that are more than a selectable time in
duration. Observe that the trigger menu at the bottom of the screen has been adapted to set the
pulse condition. See
To set the pulse width to 400 μs:
7. Press 1 to enable the cursor and adjust the pulse width.
h i
8. Use
50
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to show the TRIGGER key labels.
Figure 30.
to select 400 μs.
Figure 30. Trigger on Missing Pulses
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