Definition of Telecommunications Terms

OTDR

An Optical Time Domain Reflectometer is an instrument that sends strong pulses of light through an individual optical fiber core and uses the resultant reflections to characterise the optical fiber. An OTDR will typically show the operator the precise location of connectors, bends and breaks in optical fibers, usually to an accuracy of at least 1 metre. The mechanism of an OTDR is quite similar to a Laser Speed Gun (LIDAR).

 

VFL

A Visual Fault Locator is a relatively high power (typically red) laser that is connected to an optical fiber at one end. The laser can typically be set to remain on continuously, or blink at a variety of frequencies. Any breaks or excessive bends in the fiber along a run will be visually apparent as a red glow or blinking. VFL's are also used as a quick and easy way to indicate the end-to-end integrity of a fiber path - a technician connects the VFL at the origin, and an observer checks for a red glow at the corresponding connector at the destination end.

 

FOBOT

A Fiber Optic Break-Out Tray is an enclosure, usually manufactured in plastic, that provides a strong and secure environment to contain the fragile cores of a stripped optical fiber at a splice point or termination. A FOBOT typically consists of an outer metal rack-mount or wall-mount enclosure, containing the trays themselves. Each tray has a series of small clamps designed to hold the reinforced heat-shrink splice-protectors and curved channels to keep the individual fibers securely in place.