LeCroy SDA, Operator'S Manual

Page: 134 / 397

134
SDA-OM-E Rev H
Capture of Parameter Events
The number of events captured per waveform acquisition or display sweep depends on the
parameter type. Acquisitions are initiated by the occurrence of a trigger event. Sweeps are
equivalent to the waveform captured and displayed on an input channel (1, 2, or 3 or 4). For non-
segmented waveforms an acquisition is identical to a sweep. Whereas for segmented waveforms
an acquisition occurs for each segment and a sweep is equivalent to acquisitions for all
segments. Only the section of a waveform between the parameter cursors is used in the
calculation of parameter values and corresponding histogram events.
The following table provides a summary of the number of histogram events captured per
acquisition or sweep for each parameter, and for a waveform section between the parameter
cursors.
Parameters Number of Events Captured
duty, freq, period, width, time@lev, f@level, f80-
20%, fall, r@level, r20-80%, rise All events in the acquisition
ampl, area, base, cmean, cmedian, crms,
csdev, cycles, delay, maximum, mean,
minimum, nbph, nbpw, over+, over-, pkpk, npts,
rms, sdev, dly One event per acquisition
Histogram Parameters (XMAP and JTA2 Options)
Once a histogram is defined and generated, measurements can be performed on the histogram
itself. Typical of these are the histogram's
•
average value, standard deviation
•
most common value (parameter value of highest count bin)
•
leftmost bin position (representing the lowest measured waveform parameter value)
•
rightmost bin (representing the highest measured waveform parameter value)
Histogram parameters are provided to enable these measurements. Available through selecting
"Statistics" from the "Category" menu, they are calculated for the selected section between the
parameter cursors:
•
fwhm full width (of largest peak) at half the maximum bin
•
fwxx full width (of largest peak) at xx% the maximum bin
•
hist ampl histogram amplitude between two largest peaks
•
hist base histogram base or leftmost of two largest peaks
•
hist max value of the highest (right-most) populated bin in a histogram
•
hist mean average or mean value of data in the histogram
•
hist median value of the x-axis of a histogram that divides the population into two equal
halves
•
hist min value of the lowest (left-most) populated bin in a histogram
•
hist rms rms value of data in histogram
•
hist sdev standard deviation of values in a histogram