Glossary • 339
WAGO-I/O-SYSTEM 750
BACnet/IP Controller
F
Fieldbus
The fieldbus is a dedicated
bus
for the serial transmission of information.
Fieldbus systems connect sensors, actuators and controls from the field level
to the management level. Numerous different fieldbus systems have been
developed for various purposes. For example, the LON and KNX fieldbus
systems are used primarily in building automation, whereas CANbus and In-
terbus are applied chiefly in the automotive industry.
Firewall
Collective name for solutions that protect LANs from unauthorized access
from the internet. 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 Host.
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 permits files to be transferred
without files being accessed.
Function
Functions are modules that always return the same results (as a function
value) when the input values are identical. They have no local variables that
store values beyond an invoke.
Function Block
Function blocks are used for IEC 61131 programming and stored in libraries
for repeated utilization. A function block is a structured module, which has a
name and contains input and output variables, as well as local variables.
