232 ï GlossaryWAGO-I/O-SYSTEM 750Linux Fieldbus CouplerETHERNETSpecifies a Local Area Network (LAN), which was developed by Xerox,Intel and DEC in the 70ís. The bus access process takes place according tothe CSMA/CD method.ETHERNET StandardIn 1983 ETHERNET was standardized by IEEE 802.3 10Base-5. ISO tookover the standardization in the ISO Standard 8802/3. The essentialdifferences between ETHERNET and the IEEE standard are to be found inthe frame architecture and treatment of pad characters.FFieldbusSystem for serial information transmission between devices of automationtechnology in the process-related field area.FirewallCollective term for solutions which protect LANs connection to the Internetfrom unauthorized access. They are also able to control and regulate thetraffic from the LAN into the Internet. The crucial part of firewalls are staticrouters which have an access control list used to decide which data packetscan pass from which subscriber.FrameUnit of data transferred at the Data-Link layer. It contains the header andaddressing information.FTP(File Transfer Protocol) A standard application for TCP/IP which allowsusers on one machine to transfer files to/from another.FunctionModule that always returns the same result (as a function value), prerequisitebeing identical input values; it has no local variables that store valuesbeyond an invoke.
