Optical time domain reflectometer

Click Optical Setup in the left panel.

Click the OTDR > Provisioning tabs.

Perform these steps as needed.

1. To add an OTDR port, click +Add.

   1. In the Create OTDR dialog box, choose the Port.

   2. Click Apply.

      The OTDR port is created and added to the table that displays the following information:

      Note

      When you create an OTDR port, there are two entries with the status for direction Tx and the direction Rx.

      • Port―Displays the OTDR port name.

      • Direction―Displays the direction of the port (Rx or Tx).

      • Scan Status―Displays the status of the OTDR scan; for example, status-progress, status-failure, or status-idle.

      • Scan Progress―Displays the progress of the OTDR scan, in percentage.

      • OTDR Training Status―Displays the status of the OTDR training; for example, status-trained, and status-not-executed. The status is unique for each direction.

      • ORL Training Status―Displays the status of the ORL training. The status is unique for each direction.

      • Scan Failure Message―Displays the reason for the scan failure.

      • High Reflection Location―Displays the location of high reflection that is detected when the scan fails.

      • ORL Threshold― Displays the threshold of the ORL measure. There is an alarm (Excessive ORL Measure) associated with this field.

      • Refractive Index―Displays the fiber refractive index, which depends on the installed fiber.

      • Backscatter―Displays the reflective light on the fiber, which is also dependent on the installed fiber.

      • Loss Sensitivity―Displays the limit under which the loss is not considered as real loss, in dB.

      • Reflection Sensitivity―Displays the limit under which the reflection is not considered as a real reflection, in dB.

2. (Optional) If you want to delete a port, select one of the entries (Tx or Rx), and click Delete.

   Both entries (Tx and Rx) of the port are deleted.

To run the OTDR scan, perform these steps:

1. (Optional) Set the following values, if required.

   • Absolute Alarm Thresholds for loss and reflection

   • Loss Sensitivity and Reflection Sensitivity of the fiber

2. Choose the OTDR port on which OTDR scan has to be performed.
3. Click Start.

   "OTDR scan started" message appears.

   Note

   • You can run only one scan at a time either in TX or RX direction, for each port. When you start a scan on direction TX, the column that is related to TX direction is updated, and when you start the scan on RX, the other column is updated.

   • You can run scan on both ports (for example: ports 1 and 2 on TNCS-O, and ports 3 and 4 on TNCS-2O) at the same time.

   • You can perform as many scans as you want, but Cisco Optical Site Manager database can retain only up to two Tx scans and two Rx scans for each port. If you perform subsequent scans, the existing scan file is overwritten by the latest scan file. Hence, for each port, the web user interface displays only up to two TX scans and two RX scans.

   You can view the status of the scan under the Scan Status column.

To view the OTDR scan traces, perform these steps:

1. Click the Traces tab.
2. To set a baseline, perform these steps:

   • From the Port drop-down list, choose one of the ports you have configured, to analyze.

   • From the Last Scan Traces drop-down list, choose the scan file that you want to analyze.

   • If the selected scan had desired results and you want to set the selected scan file as a baseline, click Baseline.

   • Click Yes to confirm.

   • Click Ok in the Action dialog box.

     The baseline is saved. You can have one baseline for each direction. You can use this baseline to compare with other OTDR scan results.

3. Choose the scan file and baseline file, and click the Refresh icon next to the Port drop-down list.

   You can view the traces chart having Loss (dB) plotted against Distance (Km). The baseline chart is plotted in blue color, and the selected otdr scan chart is plotted in green color.

   To zoom into the graph, press Shift key and drag the mouse pointer to select the portion of the graph.

4. Click Download to download the data file saved in the Standard OTDR Record (SOR) format.
   The SOR file contains fiber trace data that are recorded by the OTDR instrument when testing an optical fiber.
5. Click the Export as SVG icon to download the traces file in SVG format.