Technical data

Topologies of SIMATIC NET PROFIBUS networks
2.2 Topologies of optical networks
PROFIBUS Network Manual
30 System Manual, Edition 04/2009, C79000-G8976-C124-03
Linear bus topologies
Figure 2-3 shows a typical example of a bus topology
In a bus structure, the individual SIMATIC NET PROFIBUS OLMs are connected together in
pairs by duplex fiberoptic cables.
At the start and end of a bus, OLMs with one optical channel are adequate, in between,
OLMs with two optical channels are required.
The end devices are attached to the electrical interfaces of the OLMs. Either an individual
end device or a complete PROFIBUS segment with a maximum of 31 nodes can be
connected to the RS485 interface.






Bus connector
2
1
4
3
11
42
OP 25
PG
OP 25
ET 200S
ET 200M
① Terminating resistor activated
1 Fiber-optic cables
2 PROFIBUS bus cable
3 PROFIBUS connecting cable 830-1T
4 PROFIBUS connecting cable 830-2
Figure 2-3 Example of a bus topology with OLMs