B-1
ET 200U Distributed I/O Station
EWA 4NEB 812 6087–02b
Glossary
A
Access mode
There are two access modes: read and write access
Active nodes
Can transmit data to other nodes or request data from other nodes
when they have a permission to send (= master station).
Address identifier
Combination of letters/digits identifying an ET 200U I/O module in
COM ET 200.
Arc suppression element
Components for reducing induced voltages. Induced voltages occur
when inductive circuits are de–energized.
Array
A set of elements of the same type.
In the ET 200U(DP Standard/FMS), for example, multi–channel ana-
log modules are assigned the object code “array”.
B
Baud rate
Data transmission speed: specifies the number of bits transmitted per
second (baud rate = bit rate)
Bus
Common transmission path for all nodes connected; with defined ter-
mination points.
Bus connector
Physical interface between node and bus cable.
Bus node
Device that can send, receive or amplify data via the bus, e.g. master
station, slave station, repeater, active star hub, etc.
Bus segment
³
Segment
C
Chassis
Chassis defines the entire range of interconnected dead inactive parts
of a device that are not subject to any dangerous touch voltages, even
in the case of a fault.
Communication link
A communications link forms a logical interface between two bus
nodes. Their relationships are defined in the
³
list of communications
links.
Communication reference
A communications link is established between two stations which need
to exchange data. Each station is therefore assigned at least one com-
munications link. These relationships are identified by numbers (so–
called communications references). A communications reference is
equivalent to an “internal address” of the station in layer 7.
B
