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Frequency Counter - Hertz Measurement
When this button is active the large Frequency Counter readout shows the frequency of the Trigger Source in hertz. Make sure that Trigger is active, Mode is set to Normal, and that Trigger Slope, Level, and Hysteresis are set appropriately for the signal to be measured. Note that Hysteresis is especially important for proper Frequency Counter operation when noise is present, much more so than for simple display triggering.
If the Hertz display is too jumpy, set the Frequency Counter update rate to Slow.
Trigger Holdoff should normally be set to zero. But to measure the rate of tone or noise bursts, without interference from the tone or noise itself, set Holdoff longer than the duration of the burst on-time: The trigger logic will be locked out after the first trigger of each burst is found, and won't be re-enabled until after the burst is past; it will then be ready to trigger on the next burst.
If no triggers are detected, or if Trigger is not active, the frequency remains at zero.
0 = Hz 1 = RPM 2 = msec 3 = Tot 4 = SpecTot
Note that if you use a name instead of a value in an IF test, it must be in quotes: IF.FcountMode="Hz".
Freq is an internal variable that holds the current Frequency Counter readout value, dependent on the chosen mode (Hz, RPM, msec, Total, or SpecTot). You can assign it to a variable such as F via F=Freq, or you can display it via Msg=Freq, or use it directly in an expression.
Total holds the count of total cycles counted since the last Reset, valid during Hz, RPM, or msec modes. This allows macros to get the Total value even when these other modes are active. Note that this does not work in SpecTot mode.
See also Frequency Counter
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