Technical data

Topologies of SIMATIC NET PROFIBUS networks
2.2 Topologies of optical networks
PROFIBUS Network Manual
34 System Manual, Edition 04/2009, C79000-G8976-C124-03
2.2.4 Combination of integrated optical interfaces and OLMs
Options for combinations with OLM
Note
You will find information on combinations with OLMs in the operating manual of the OLM on
the Internet (
http://support.automation.siemens.com/WW/view/en/24164176).
Attaching glass FO cables to buses made up of integrated optical interfaces
The operating wavelength of the integrated optical interfaces and the OBT is optimized for
the use of plastic or PCF fibers. The direct attachment of glass FO cables is not possible.
If a link with glass FO cable is required, for example to span distances of more than 300 m,
this link must be implemented with OLMs. The attachment of glass links to the optical bus
made up of integrated optical interfaces is via the RS485 interface of an OBT. The following
schematic shows an example of an application.
Field device without
FO interface
Further nodes
ET 200M with
IM 153-2FO
1 2
PG
3
1
OBT
ET 200M
1
OBT
OBTOBT

 


 
11
4
3

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 2-7 Attachment of an optical glass link to an optical bus made up of integrated optical
interfaces