232
•
Glossary
WAGO-I/O-SYSTEM
750
Linux Fieldbus Coupler
ETHERNET
Specifies a Local Area Network (LAN), which was developed by Xerox,
Intel and DEC in the 70’s. The bus access process takes place according to
the
CSMA/CD
method.
ETHERNET Standard
In 1983 ETHERNET was standardized by
IEEE 802.3
10Base-5. ISO took
over the standardization in the ISO Standard 8802/3. The essential
differences between ETHERNET and the IEEE standard are to be found in
the frame architecture and treatment of pad characters.
F
Fieldbus
System for serial information transmission between devices of automation
technology in the process-related field area.
Firewall
Collective term for solutions which protect
LANs
connection to the
Internet
from unauthorized access. They are also able to control and regulate the
traffic from the LAN into the Internet. The crucial part of firewalls are static
routers
which have an access control list used to decide which data packets
can pass from which
subscriber
.
Frame
Unit of data transferred at the Data-Link layer. It contains the header and
addressing information.
FTP
(File Transfer Protocol) A standard application for
TCP/IP
which allows
users on one machine to transfer files to/from another.
Function
Module
that always returns the same result (as a function value), prerequisite
being identical input values; it has no local variables that store values
beyond an invoke.