Technical data

150 Theoretical and general applications www.westermo.com
Faxmodem A modem that can send and receive data information
(text, images) in fax format.
FDDI Fibre Distributed Data Interface: A standard for fibre-optic
networks.
Fibre optics Modulated laser light or laser beams from light emitting diodes
through thin glass or plastic fibre, normally between 800–1300 nm
(nanometre). Bunches of fibre cable can transfer vast amounts of
information.
Fieldbus A defined standard for industrial data networks, for example,
PROFIBUS.
Firewall A router used to screen IP addresses.
Four wire Twisted pair 4-wire cable.
FP A Fibre Optic Ethernet Port.
Frame A Frame is data that is sent between two Ethernet devices as a
complete unit with addressing and protocol control information.
The information is passed serially bit-by-bit.
Frequency Technology to transfer information by varying the
modulation frequency of the carrier wave.
FRNT Fast Re-Configuration Network Topology. Ethernet switches are
placed into multiple redundant rings. Enhanced redundancy is pro-
vided by linking separate rings with backup paths.
FTP File Transfer Protocol.This is the one of the simplest ways
of transferring files across the internet. It uses the TCP/IP
protocols to enable file transfer.
Full duplex Bi-directional communication where signals can flow
in both directions simultaneously.
Galvanic isolation Means electrical isolation, i.e. no electrical contact.
GPRS General Packet Radio Service. A service offered in GSM to han-
dle packet switching data traffic.
GPRS Attach An inquiry from GSM equipment concerning permission to con-
nect to a GPRS network.
GPS Global Position System. A satellite navigation system based on
24 satellites orbiting the world. Each satellite contains an atomic
clock accurate to within a billionth of a second.
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