4-2
FIM-102D FIBER INTERFACE
multimode fiber-optic cable
The glass core of a multimode fiber is larger than the core of a single mode fiber,
which causes the transmitted light beam to disperse as it travels through the core. Single mode fiber, with its smaller
core, concentrates the light beam so that it carries signals further. Multimode fiber was the first type of fiber offered
by manufacturers. Single-mode fiber evolved as production methods improved.
multiplexing
The process by which two or more signals are transmitted over a single communications channel.
Examples include time division and wavelength division multiplexing.
nanometer (nm)
Common unit of measure for wavelength. One billionth of a meter.
optical signal
A laser at one end of a fiber-optic cable pulses on or off to send a light signal through the glass core
of the cable to the other end of the cable. Because the light signals are binary (on or off), the signal is digital.
port
Any of the input/output connections (RJ-45 connectors) on the back panel of the central matrix. These
connectors and the attached cables connect the central matrix to remote intercom devices. The term “port”
emphasizes that the connection is a “portal” between the central matrix and the remote intercom devices.
remote station
Any intelligent intercom device connected to the back-panel ports of the central matrix. This term
does not refer to devices connected through interfaces.
single-mode fiber-optic cable
The glass core of a single-mode fiber is smaller in diameter than the core of a
multimode fiber, so that the light signal transmitted over the core is more concentrated than with multimode fiber,
which allows the signal to travel further. Single-mode fiber evolved from multimode fiber as production methods
improved.
