HP 54520 Series - Page 111

Display Menu
Repetitive Acquisition Display Menu
Norm (Normal) The norma! mode sets the time parameters for
displaying data or selecting persistence. The range in the variable
persistence mode is from minimum, very fast overwriting and updating of
the display, to infinite with variable settings from 500 ms to 10 seconds.
Persistence allows you to display data records to any of the persistence
settings. For settings of less than infinite, the data is displayed for the
specified period of time. When norm is selected, the function key below
the normal field is activated. This field displays the current persistence
setting. The following are some hints in using the normal display mode:
e Connect-the-dots is available in the minimum persistence, average, and
envelope display modes.
e Use fast persistence settings when the input signal is changing and when
immediate display feedback is needed.
e@ Use more persistence when observing long-term changes in the signal or in
ow-repetition-rate signals.
e Use infinite persistence for worst-case characterizations of signal noise,
jitter, and drift. The persistence mode is similar to a storage oscilloscope.
At minimum persistence, a point is erased when a new point is acquired in
the same time bucket on the display. Therefore, the waveform fills in quickly
and each point remains for a minimum amount of time. Measurements are
performed using the newest data in each pixel column.
When the keypad is used to change persistence settings, any entry longer
than 10 seconds displays the message "value out of range... set to limit", and
persistence is automatically set to infinite. Any entry less than 500 ms causes
the same message to be displayed, and persistence is set to minimum.
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