Optical fibre monitoring software detects occasional faults

A new software package allows the Yokogawa AQ7275 optical time-domain reflectometer (OTDR) to be used in unattended mode for detecting and monitoring faults occurring occasionally or at regular or irregular intervals in fibre-optic networks.

The new AQ7940 software is designed to meet the needs of operators or users of fibre-optic networks in locations that may be prone to occasional faults caused by temperature variations, moisture ingress, insects or rodent attacks. Traditional remote monitoring systems, normally used on larger-scale networks, are complex to set up, expensive and require highly trained operators, whereas the AQ7940 offers a solution that is both easy to operate and inexpensive.

In a typical application, the unattended OTDR is controlled by a PC via a USB or Ethernet interface. Using the Yokogawa AQ7940 monitoring software, the instrument can then continuously monitor optical lines, without the need for an engineer to be present.

With this setup, all line interruptions down to 100 ms are detected, and the corresponding measurement results (including OTDR traces) are logged by the PC software to produce a fault data log. The operator then simply checks the logged data to see what has happened during the period of unattended operation.

The AQ7275 OTDR offers a 100 ms response time at wavelengths of 850, 1300, 1310, 1550 and 1625 nm. A filter provides active line monitoring at the 1625 nm wavelength.