Luna 4600 - Editing a Reference Trace: Processing Parameters and General Tolerances

94 Chapter 6
LightPath Analysis Software Guide
6
Press the Close button to exit the Trace Comparison window. Note that the loaded
trace is still device3.obr, and the lower graph data is not reprocessed.
Press the Save LightPath Files button to save the LightPath data for device3.obr.
Enter device3 as the descriptor for new data folder, and press OK.
Editing a Reference Trace: Processing Parameters and General
To lerances
Above under “Editing Feature-Specific Tolerances” on page 88, you learned how
to edit feature-specific tolerances in the Reference Trace. Reference files also
contain processing parameters and general tolerance values like those in the
Parameter Configuration File. These values can be modified to affect the way
features are detected, and to change general tolerances.
Select Setup > Data Processing Parameters from the main menu. The Parameter
Specifications window is shown again (Figure 6-4 on page 83), this time displaying
the parameters and tolerances contained in the Reference Trace file “golden.”
The Processing Parameters and General Tolerances for the golden reference are
currently the same values (contained in lpa_default_params.ini) that were in use
when the trace was saved. These values can be changed so that future traces being
compared to the Reference Trace file “golden” will be processed using a different
set of parameters and tolerances.
Changing the General Tolerances for a Reference Trace will change the tolerance
values used to evaluate extra features. For example, changing the value of (IL) Loss
Tolerance (dB) to 3.5 would cause the extra feature in device3.obr to pass based
on (insertion) Loss (although it would still fail for being a feature not present in the
Reference Trace). More importantly, these are the values that would be used if both
the Compare to Reference Trace and Use General Tolerances checkboxes were
selected in the Specify File Paths window (Figure 6-2 on page 80).
Change the Processing Parameters in a Reference Trace with caution, because new
traces will be processed differently from the way the original Reference Trace was
processed. For example, changing the Feature Extract Length (m) back to 0.1
would collapse the two peaks at 1.6 and 1.9 m back into a single feature when
processing any new data. This would make it impossible for any new trace to match
the Reference, which would still retain the two distinct peaks.