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Making Measurements
Making time measurements automatically
Measurement definitions
Counter
The Counter measurement counts trigger level crossings at the selected trigger
slope and displays the results in Hz. The gate time for the measurement is
automatically adjusted to be 100 ms or twice the current time window, which
ever is l ong er, up t o 1 s eco nd. Any ch ann el e xce pt M ath may be sel ect ed f or t he
source. Only one Counter measurement may be displayed at a time.
The Y cursor shows the edge threshold level used in the measurement.
The Counter measurement can measure frequencies up to 125 MHz. The
minimum frequency supported is 1/(2 X gate time).
Duty Cycle
The duty cycle of a repetitive pulse train is the ratio of the positive pulse width
to the period, expressed as a percentage. The X cur sors show the time period
being measured. The Y cursor shows the 50% point.
Frequency
Fre qu en cy is de f in ed as 1/ Pe r io d. Pe ri od is d ef in ed as th e ti me be tw ee n t h e 5 0%
threshold crossings of two consecutive, like-polarity edges. A 50% crossing must
also travel through the 10% and 90% levels which eliminates runt pulses. The
X cursors show what portion of the waveform is being measured. The Y cursor
shows the 50% point.
Period
Period is the time period of the complete waveform cycle. The time is measured
between the 50% points of two consecutive, like-polarity edges. A 50% crossing
must also travel through the 10% and 90% levels which eliminates runt pulses.
The X cursors show what portion of the waveform is being measured. The Y
cursor shows the 50% point.
Duty cycle = + Width
Period
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