Teledyne LeCroy WavePro Automation Command User Manual
Page 314

Automation Command and Query Reference Manual - Control Reference
MinAverages
Integer
From 10 to 1000 step 1
Range
DDJ is determined from the means of the distributions of edges within a pattern. In order to identify
those means with adequate precision, a reasonable number of occurances of the pattern must be
observed. This control sets that number. Until this number of occurances are observed the results of
Pattern Analysis will not be valid.
Description
PatternLength
Integer
From 1 to 2000000 step 1
Range
This read-only control tells whoever reads it the length of the currently detected repeating pattern. For
example, for a PRBS 7, this control would be set to 127 by SDA2.
Description
' Visual Basic Script
Set app = CreateObject("LeCroy.XStreamDSO")
patternlength = app.SDA2.JitterMeasure.Pattern.PatternLength
Example
PatternShiftLeft
Action
When the SDA2 displays a sequence of hex digits as the pattern in HexPattern (see HexPattern,
above) then it may be helpful to the user to shift the starting bit of the pattern so that the hex
characters are recognizable to the user. This control allows the user to shift the starting bit to the
left. See also: PatternShiftStep, below.
If HexPattern displays a pattern name, such as PRBS7, then this control has no discernable affect.
Description
PatternShiftRight
Action
When the SDA2 displays a sequence of hex digits as the pattern in HexPattern (see HexPattern,
above) then it may be helpful to the user to shift the starting bit of the pattern so that the hex
characters are recognizable to the user. This control allows the user to shift the starting bit to the
right. See also: PatternShiftStep, below.
If HexPattern displays a pattern name, such as PRBS7, then this control has no discernable affect.
Description
PatternShiftStep
Integer
From 1 to 100 step 1
Range
This sets the number of bits that the HexPattern display is shifted by PatternShiftLeft and
PatternShiftRight. Default is 1 bit.
Description
ShowDDjHisto
Bool
This control corresponds to the "ShowDDj Histogram" checkbox on the Pattern Analysis right side
dialog. Setting this control to True enables display of the DDj Histogram, which shows the offsets
from 0 time of the mean edge positions for all edges in the pattern. For example, for a PRBS7, which
is 127 bits long and has a transition density of 0.5, the DDjHiso has a total population of 64 - one value
for each of the 64 edges in that pattern. For more information on DDJ see "NumberOfBits", above,
Description
1-300
918501 RevA