Operating instructions

Glossary
Glossary-8
SIMATIC NET Twisted-Pair and Fiber-Optic Networks
C79000-G8976-C125-02
S/STP
Screened Shielded Twisted Pair
With this cable design, the individual twisted pairs of a twisted pair cable are
wrapped in a foil screen. Both individually screened pairs are also shielded with a
common braided copper shield.
Standard rail
Metal rail standardized in compliance with EN 50 022.
The standard rail is used for fast snap-on installation of suitably designed devi-
ces (for example OLM, ELM, OSM)
Structured cabling
Generic cabling system within buildings and building complexes for information
technology purposes. The European standard EN 50173 “Application
Independent Generic Cabling Systems” contains specifications.
This divides a campus into the following areas
– Primary area (connections between buildings of a campus)
– Secondary area (connections between floors of a building)
– Tertiary area (connections to the DTEs).
EN 50173 recommends cabling systems adapted to these areas that provide the
flexibility for the communication requirements of the future independent of
specific applications.
Suppressor
Component for reducing induced voltages. Induced voltages occur when circuits
with inductances are turned off.
Switch, Switching
A switch is a network component with essentially the same characteristics as a
bridge. In contrast to bridges, however, the switch can establish multiple
connections between its ports simultaneously. These connections are
established dynamically and temporarily depending on the data traffic. Each
connection has the full nominal bandwidth.
Terminating resistor
A resistor to terminate Industrial Ethernet triaxial cable; terminating resistors are
always necessary at the ends of triaxial cable.
TP cord
A category 5 twisted pair cable for short links; intended for use in a wiring closet
or in an office environment with low levels of electromagnetic interference.