OTDR files and fault location

Review measurements and events in a SOR file and locate a selected event's estimated position in the network.

Last updated: 10 November 2026

Attach a SOR file to a measurement

An OTDR measurement file lets you inspect event distances and optical information alongside the measurement record. Values read from the file are suggestions; existing measurement fields are not changed without your explicit selection.

1. Open Measurements for a circuit, Fiber measurements for a cable or Port measurements for equipment.
2. Use Add measurement to create an OTDR measurement, or Upload file on an existing measurement.
3. Select the .sor file in File (optional) and save. Check that the file upload has also completed.
4. Select SOR contents on the measurement row.
5. Review Wavelength, Refractive index, Pulse, Range, End-to-end loss / ORL and the event table.

A status explanation appears if the file cannot be read or parsing is disabled. A successful upload does not mean its events were read successfully. Use Parse again if needed and check the result.

Fill measurement fields from the file

1. Read mismatch warnings in SOR contents. Wavelength, loss, date or fiber ID may differ from the record.
2. Select the Events, Wavelength and Value fields to transfer.
3. Select Fill from SOR.
4. Check the current measurement values; use Load current measurement if needed.

The cable or fiber ID in the file is informational; check separately that the measurement is attached to the correct target. For an uncertain save result, follow Confirm previous save result.

Locate an event on the map

1. Select On map on the event row, or open OTDR in Outage.
2. Select SOR measurement and Event. Use Refresh measurements if a new record is missing.
3. If measurement direction is unclear, select the starting Anchor node… and the relevant fiber or port.
4. Select Locate.
5. Inspect the cable, distance, map marker and explanations in OTDR position.

To work without a file, select Manual distance and anchor; enter the starting endpoint, Distance (m) and Refractive index (optional) if available.

The displayed location is an estimate. The recorded path, cable length, measurement direction and refractive index affect the result. Read uncertainty or uncalculable-path warnings and verify in the field. See Optical budgets and measurements for the measurement's relationship to a calculation.