Operating instructions

Active Components and Topologies
6-3
SIMATIC NET Tw isted-Pair and Fiber-Optic Networks
C79000-G8976-C125-02
Overview
The SIMATIC NET link modules for Industrial Ethernet allow flexible configuration
of Ethernet networks complying with the IEEE 802.3 standard using fiber-optic or
copper cables. The transmission rate on all interfaces is 10Mbps. The link modules
are fitted on to a standard rail.
The OLMs (Optical Link Modules) have three Industrial Twisted Pair (ITP) ports
and two optical ports (BFOC). With ITP, up to three DTEs or further ITP segments
can be connected; with fiber-optic cable, connection of up to two further DTEs or
optical network components (OLM, star coupler with ECFL2 (Extension Card Fiber
Link) etc.) are possible.
The ELMs (Electrical Link Modules) also have an AUI port in addition to the three
Industrial Twisted Pair (ITP) ports. An Ethernet segment with triaxial cable can be
connected to the AUI port via a 727-1 drop cable and a transceiver.
Both modules conform to the specifications of the IEEE 802.3 /1/ standard.