Siemens ST PCS 7 User Manual

PROFIBUS DP

Siemens ST PCS 7 · November 2007

9

■

SIMATIC NET plastic/PCF fiber-optic cables can be used to 

design optical PROFIBUS DP networks inside buildings. 
For AS interfacing of ET 200M with exclusively F modules, 

plastic/PCF fiber-optic cables are an alternative if compliance 

with safety integrity level SIL 3 is required for the safety-related 

application. Using plastic/PCF fiber-optic cables, the ET 200M 

systems are connected to the electrical bus cable of the 

PROFIBUS DP via optical bus terminals (OBT). The advantage 

of this configuration is that the isolating module essential for sig-

nal decoupling between the IM and the F modules in the case of 

a direct electrical connection of the ET 200M (only F modules in 

a rack with IM 153-2) can be omitted.

Using the OBT (optical bus terminal) for PROFIBUS, it is possible 

to connect a PROFIBUS DP station with integrated optical inter-

faces to an RS 485 segment or a PROFIBUS DP station without 

integrated optical interface. Plastic/PCF fiber-optic cables can 

be used for the optical connection between the PROFIBUS DP 

station with integrated optical interface and the OBT.

■

We particularly recommend the following plastic/PCF standard 

cables for implementing optical networks in indoor areas:
• PROFIBUS Plastic Fiber Optic standard cable: 

- Rugged round cable with purple PVC outer casing and Kev-

lar tension-relief elements as well as plastic fibers with rug-

ged polyamide inner casing.

- Easy to assemble on site with 2 x 2 Simplex connectors

- Cable lengths up to 50 m

• PROFIBUS PCF Fiber Optic standard cable: 

- Preassembled, rugged round cable with purple PVC outer 

casing and Kevlar tension-relief elements as well as two PCF 

fibers (Polymer Optical Fiber)

- Cannot be assembled on site

- Cable lengths up to 300 m

Further SIMATIC NET plastic/PCF fiber optic cables can be 

found in Catalog IK PI, Chapter "PROFIBUS", Section "Optical 

networks with OBT and integrated interface".

The following components are available for on-site assembly of 

the PROFIBUS Plastic Fiber Optic standard cable:
• Simplex connector/polishing set (set with 100 simplex con-

nectors and 5 polishing sets)

• Stripping tool set for removing the outer casing and core cas-

ing

• You require additional plug adapters for connecting cables 

with Simplex connectors to devices with integrated FO inter-

faces (e.g. IM 153-2 FO).

B) Subject to export regulations: AL: N, ECCN: EAR99H

:

For further information on optical PROFIBUS networks as well as compo-

nents and accessories, particularly cable material for special applica-

tions, refer to Catalog IK PI, Chapter "PROFIBUS", Section "Optical 

networks with OLM" and "Optical networks with OBT and integral inter-

face".

OBT

IM 153-2

IM 153-2 FO

OBT

Safety-related
automation system

ET 200M
with standard
I/O modules

ET 200M
with safety-
related
F modules

■

Order No.

Optical bus terminal for connect-

ing a PROFIBUS station or an RS 

485 segment without integrated 

optical interface to the optical 

PROFIBUS; without simplex con-

nector

Robust round cable with 2 plastic 

fiber optic cores, PVC external 

sheath and PA internal sheath, 

without connectors, for indoor 

use, cut-to-length

Plastic fiber optic cable with 

2 cores, PVC sheath, without con-

nectors, for use in environments 

with low mechanical stress, 50-m 

ring

B)

100 simplex connectors and 

5 polishing sets for assembling 

PROFIBUS plastic fiber optic 

cables for the optical PROFIBUS 

DP

B)

To remove the external or core 

sleeve of plastic fiber optic 

cables

B)

Pack of 50, for using simplex con-

nectors with the integrated 

FO interfaces (e.g. IM 153-2 FO); 

for 25 modules

© Siemens AG 2007