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Counting pulses with Infiniium and EZJIT

Question asked by jtmccabe Employee on Aug 3, 2007
Infiniium oscilloscopes do not offer an automatic measurement that counts the number of pulses that have been captured.  However, the E2681A EZJIT software provides a roundabout way to get a quick and accurate pulse count.  Simply enable Jitter Mode and turn on the positive or negative pulse width measurement.  Now the scope will measure the pulse width of all acquired cycles rather than just a single cycle.  Even though you may not care about how the pulse width varies over time, you can make use of the "# of Meas" value reported at the lower left of the screen: 

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In this case, we have captured 500 us of a 100 MHz clock.  Theory predicts that we should have captured 50,000 cycles during that interval.  EZJIT reports the number of measurements as 49.998k, so we know that it detected that many complete pulses. 

Note that if you try this, you will need to use the small scroll bar to the left of the measurements to scroll down and see the number of measurements.  Also, please be aware that the number of measurements is limited to about 1M per trigger, and is represented with a maximum of five significant digits.  

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