Luna 4600 - Comparing a Failing Trace to the Reference; Comparing Traces Using the Trace Comparison Window

Optical Backscatter Reflectometer 4600 93
User Guide
6
Comparing a Failing Trace to the Reference
Load the file device3.obr (File > Load Data File). This file is similar to device1.obr
but shows an extra peak around 0.54 meters. Press the Compare button to view the
Trace Comparison window.
The Reference Trace Event Listing and Trace Event Listing entries are ordered
so that matching features are aligned. The extra peak and fiber segment in
device3.obr are shown in Trace Event Features 6 and 7, which have no
corresponding entries in the Reference Trace Event Listing. If a trace had missing
features, they would be displayed as features in the Reference Trace Event Listing
with no corresponding features in Trace Event Listing.
Select each of the features to verify that the extra peak and fiber are the only failing
features. In the Feature Tolerance Detail area on the left, the extra features should
show as failing (red) both in Feature Type and Location. Note that the Min and
Max Loss values for the extra features have been
compared to the Reference Trace’s
General Tolerance values, since there is no reference feature to compare them to.
When Feature 6 of device3.obr is shown as High Resolution Data (using the graph
pull-down menu), only red data is displayed, since there is no Reference Trace
(blue) data saved at that location.
Comparing Traces Using the Trace Comparison Window
From the Trace Comparison window, one can open and compare other files without
using the File > Load Data File command or the Setup > File Configuration
command in the main window. Comparing other files in the Trace Comparison
window only changes the Reference Trace or compared data
temporarily. When this
window is closed, the software returns to the data loaded using the File > Load Data
File command, and to the Reference Trace chosen in the Specify File Paths window
(Figure 6-2 on page 80).
To compare the current Reference to a different trace, press the browse button to
the right of the Trace File Folder control and select the directory
C:\LPA_Data\device2. This compares the reference file to the device2 files created
earlier in the tutorial. All features should be again be marked as passing.
Similarly, you can use the Reference Trace File Folder browse button to select a
different Reference for comparison to the current trace. By using both controls to
select two different folders, any reference or evaluation trace can be compared to
another. (However, it is of limited use to compare two traces unrelated to either the
current reference or the currently loaded trace.)