Planning/Configuring; Network Topologies; Possible Network Topologies; Installation Guide - Siemens SIMATIC NET Operating Instructions Manual

Planning/configuring

7.1

Network topologies

7.1.1

Possible network topologies

The following network topologies can be implemented with the PROFIBUS OLM:
● Point-to-point connection
● Bus topology
● Star topology
● Redundant optical ring
Combinations of these basic types are also possible. To set up the fiber-optic links of these
network topologies, cables with two optical fibers are used.
If a high degree of availability is required of the fieldbus network, this can be increased by
using a redundant network configuration, for example to allow continued communication if a
cable is broken.
7.1.2

Installation guide

Note the following guidelines:
● Single end devices or complete PROFIBUS segments with a maximum of 31 nodes can
be connected to the electrical interface of the PROFIBUS OLM.
● In areas subject to heavy noise, use only fiber-optic cables to avoid EMC problems
affecting the entire network.
● Only connect OLMs of the same wavelength to each other optically:
– OLM / P11, OLM / P12 and OLM / P22 with each other
– OLM / G11, OLM / G12 and OLM / G22 and OLM / G12 EEC with each other
– OLM / G11-1300 and OLM / G12-1300 with each other
● Set optical channels connected via fiber-optic cables to the same mode.
● Changing from one OLM type to another is only possible via the RS-485 interface.
● In the network topologies described below, the OLM / G12-EEC can be used everywhere
where an OLM / G12 can be used.
● For the electrical connection of the OLMs only the supplied connectors may be used.
When using existing connectors (e.g. from OLM V3) correct contact is not guaranteed
due to different pin diameters.
Optical link module
Operating Instructions, 01/2020, C79000-G8976-C270-06
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