Converting Data From Metallic Cable to Fiber-Optics and Back

Where Category 5e, 6, and 7 metallic cable transmits data by way of electrons, fiber-optic cable uses light. The cable used for this purpose is made up of glass or plastic fibers surrounded by layers of various materials that serve to protect them from harm.

“Fiber optics transmit data in the form of light particles -- or photons -- that pulse through a fiber optic cable. The glass fiber core and the cladding each have a different refractive index that bends incoming light at a certain angle. When light signals are sent through the fiber optic cable, they reflect off the core and cladding in a series of zig-zag bounces, adhering to a process called total internal reflection” (fiber optics, TechTarget, http://bit.ly/2WNAaFJ).

Fiber-optic cable is ideal for long-distant signal transmission applications. This is because light will carry data for much longer distances without the usual signal degradation so typical of metallic cable. The only problem, most of the time this data starts out over metallic cable and it must be converted to light for use with fiber-optic cable. The question is, how do we go from metallic cable to fiber and back?

To make this conversion possible, a fiber adapter is necessary. This device will extend the effective transmission distance from the customary 328 feet to more than 3,000 feet. This application is ideal when connecting a remote workstation to a wired hub or switch in a computer network.

In this case the modular plug installed on the end of a metallic UTP (Unshielded Twisted Pair) cable is simply inserted into an adapter at the one end of the circuit and the opposing end is inserted into another adapter at the other end. There are conversion devices also available that make the metallic to fiber conversion at a wired hub or switch. The 100Base-FX standard, for example, uses fiber-optical cable to extend the transmission distance up to 1.2 miles. Compare this to the usual 328 feet limitation of metallic 100Base-T.

“All stations are wired in a star configuration to a repeater or central concentrator using SC, ST or MIC connectors. See Ethernet and 100Base-T” (http://bit.ly/2WOKWM2).

Today’s fiber converters also are built for speed and convenience. For example, according to Interlogix, the firm’s IFS DE7200M series 10/100 Mbps Ethernet Mini 2-Port Media Converter will function as a 10 Mbps Ethernet link, or as a 100 Mbps Ethernet link without any adjustments.

We’ll cover fiber conversion in greater detail in a subsequent blog post here on the Cables.com blog.