Figure 21: Timing Display Of Non-Integer Multiples Of Reference Rates - Tektronix WFM5200 User Manual

WFM5200 Waveform Monitor User Manual
Non-integer multiples of reference rates. If you time input rates that are not
integer multiples of the reference rates, the instrument cannot measure the
timing deterministically, so it displays the relationships as several circles. Each
circle represents a possible timing offset measurement relative to the reference
cross-hair. Display emphasis is given to the circle that times closest to zero offset
and the numerical readouts track this pair. (See Figure 21.)

Figure 21: Timing display of non-integer multiples of reference rates

Non-deterministic cases include timing of slow rate inputs against fast frame-rate
references or when timing video against film rates.
Multiple relationships. For a case where multiple relationships would display,
consider an input of 1080p/23.98 Hz with a reference of NTSC/59.94 Hz:
The different rates result in timing relationships between the signals that
repeat once for every four fields of the input and five frames of the reference.
Because this allows for five possible ways to measure timing between these
two signals, the timing display shows four circles, with emphasis and readouts
as previously described above.
Display Information
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