Optical Backscatter Reflectometer 4600 85
User Guide
software is using a Parameter Configuration File for comparisons, there is no data
in the Reference Trace Event Listing grid. (Once a Reference Trace is specified,
this grid will contain data, as shown in Figure 6-10 on page 92.)
The Trace File Folder area shows the location of the trace being evaluated, in this
case the currently loaded data held in a temporary directory. The features detected
in the current trace are shown in the Trace Event Listing grid. This grid shows the
Type, Return Loss, Insertion Loss, Location, and Result (Pass or Fail) for each
feature. (Note that all fiber segments are listed with a return loss of 0 dB.)
The Feature Tolerance Detail area at the left displays the tolerated minimum and
maximum loss and location values for the feature highlighted in the Trace Event
Listing grid. If a feature fails any given tolerance setting, that setting will show in
red in the Feature Tolerance Detail area. You may see the Feature Tolerance
Details of a different feature by clicking on it in the Trace Event Listing grid.
The highlighted feature in the Trace Event Listing grid is bold in the Feature
Highlight graph. You can also highlight a specific feature in the graph by toggling
on (clicking) the vertical cursor control and then the cross-hair tool. Once
the cursor is a cross-hair, you can click and drag over the graph to highlight each
feature. The cursor will sit at the center or splice location of the selected feature.
Select several different features, using either the graph cursor or the Trace Event
Listing grid, and view the Feature Tolerance Detail values to understand why each
feature passed or failed.
Note the sign convention for Loss (insertion loss): a drop from the input level to
the output level is reported as a positive value. A gain is reported as a negative value,
or a “negative loss.” The fiber segments in Features 11, 13, and 15 all have gains
and report negative values.
For the example file device1.obr, the peaks in Features 4, 8, and 10 have return
losses greater than the maximum value of -65 dB. Features 6 and 10 have an
insertion loss greater than the maximum of 2.0 dB. The fiber segments in Features
11 and 13 have insertion losses less than the minimum of -0.1 dB.
Press Close to exit the Trace Comparison window. Next we will show how to
change the Parameter Configuration File so that these failed features will pass.
Editing General Tolerances
Select Setup > Data Processing Parameters. This returns you to the Parameter
Specifications window (Figure 6-4). In the General Tolerances area, change the
To Next Page
Loading...
