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Reference
WFM700 Series Waveform Monitors User Manual
3-25
Reporting Jitter Measurement Errors. When enabled in the Physical Alarms
submenu of the Configure menu, the Jitter alarm will be reported to the Event
Log in only the following two conditions:
H When the Jitter display is selected
H When the Event Log or Alarm Status displays are selected after the Jitter
display is selected
That is, if you enter the Jitter display and then use the STATUS button to view
the Event Log or Alarm Status displays, the jitter measurement alarm will be
active. If you select another display mode such as Eye or Waveform, the jitter
measurement alarm will be disabled.
Use the Set Default Thresholds soft key to set the thresholds back to the default
values for the type of signal you are monitoring: SD (SMPTE 259M) or
HD (SMPTE 292M). The default value for the jitter measurement 0.2 UI, which
is the maximum alignment jitter specification for both SD and HD signals and is
the maximum timing jitter specification for SD signals (see Table 3--3).
Since the maximum timing jitter specification for HD signals is 1.0 UI, you must
set the high-pass filter to 10 Hz and manually set the jitter threshold to 1.0 UI
before the instrument will properly generate an alarm if the HD signal exceeds
the SMPTE 292M timing jitter specification.
Use the Set Meas. Thresholds soft key to set a custom threshold level.
Table 3- 3: Jitter measurement alarm thresholds
Signal type High pass filter setting Alarm threshold
SD (SMPTE 259M) 10 Hz (timing jitter)
1 kHz (alignment jitter)
0.2 UI (740 ps)
0.2 UI (740 ps)
HD (SMPTE 292M) 10 Hz (timing jitter)
100 kHz (alignment jitter)
1.0 UI (673 ps)
0.2 UI (134 ps)