
12
3 Network Topologies
Version 1.0 8/00
3.2 Star topology
3.2 Star topology
Fig. 3: Network structure in an optic star topology
Terminal unit /
bus segment
Terminal unit /
bus segment
Terminal unit /
bus segment
Terminal unit /
bus segment
Terminal unit /
bus segment
CH 2
T
R
OLM/P1
1
CH 1
CH 2
T
R
OLM/P1
1
CH 1
CH 2
T
R
CH 3
T
R
OLM/G1
2
CH 1
CH 2
T
R
OLM/G1
1
-1300
CH 1
OLM/P1
1
CH 2
T
R
CH 1
OLM/G1
1
-1300
CH 2
T
R
CH 1
OLM/P1
1
CH 2
T
R
CH 1
OLM/G1
1
CH 2
T
R
CH 1
OLM/G1
1
CH 2
T
R
CH 1
Electrical star segment
S0 = 1
S0 = 1
S0 = 1
S0 = 1
RS 485 bus line
Optical fiber
Several modules are combined to form an active PROFIBUS star coupler. Other modules are connected to this by
dual-fiber optical fiber lines. The modules of the star coupler are connected to one another via the electrical port
(electrical star segment).
All OLM types for different fiber types (plastic, PCF, glass) can be combined using the electrical star segment.
Please note:
CH1 in mode ”Monitor off“ (S0 = 1) must be activated on all OLMs which are connected to the electrical star
segment. This deactivates the segmenting function of the RS 485 port on these OLMs, providing a high degree
of availability of the electrical star segment.
Ensure that the electrical star segment is wired carefully. Keep it as small as possible to avoid interference
injection into the electrical star segment, and from here into the entire network. This can be achieved by laying
out the OLMs in the electrical star segment directly next to each other on a hat rail.
Summary of Contents for SIMATIC NET PROFIBUS
Page 10: ...Contents viii PROFIBUS Networks SIMATIC NET 6GK1970 5CA20 0AA1 Release 2 05 2000 ...
Page 11: ...PROFIBUS NETWORKS 1 ...
Page 26: ...PROFIBUS NETWORKS 1 16 PROFIBUS Networks SIMATIC NET 6GK1970 5CA20 0AA1 Release 2 05 2000 ...
Page 241: ...A 1 PROFIBUS Networks SIMATIC NET 6GK1970 5CA20 0AA1 Release 2 05 2000 Testing PROFIBUS A ...
Page 254: ...Testing PROFIBUS A 14 PROFIBUS Networks SIMATIC NET 6GK1970 5CA20 0AA1 Release 2 05 2000 ...
Page 288: ...Installing LAN Cables C 26 PROFIBUS Networks SIMATIC NET 6GK1970 5CA20 0AA1 Release 2 05 2000 ...
Page 325: ...F 1 PROFIBUS Networks SIMATIC NET 6GK1970 5CA20 0AA1 Release 2 05 2000 Dimension Drawings F ...
Page 338: ...Dimension Drawings F 14 PROFIBUS Networks SIMATIC NET 6GK1970 5CA20 0AA1 Release 2 05 2000 ...
Page 396: ...Infrared Link Modul ILM 6ZB530 3AC30 0BA1 54 Copyright by Siemens ...
Page 434: ......
Page 438: ...Contents ii PROFIBUS Optical Bus Terminal OBT C79000 G8976 C122 02 Contents ...
Page 450: ...Network Topology 4 4 PROFIBUS Optical Bus Terminal OBT C79000 G8976 C122 02 ...
Page 458: ...Installation and Startup 5 8 PROFIBUS Optical Bus Terminal OBT C79000 G8976 C122 02 ...
Page 460: ...Troubleshooting 6 2 PROFIBUS Optical Bus Terminal OBT C79000 G8976 C122 02 ...
Page 464: ...Technical Specifications 7 4 PROFIBUS Optical Bus Terminal OBT C79000 G8976 C122 02 ...
Page 468: ...References 9 2 PROFIBUS Optical Bus Terminal OBT C79000 G8976 C122 02 ...
Page 470: ...Abbreviations 10 2 PROFIBUS Optical Bus Terminal OBT C79000 G8976 C122 02 ...
Page 478: ...References I 4 PROFIBUS Networks SIMATIC NET 6GK1970 5CA20 0AA1 Release 2 05 2000 ...
Page 488: ...Glossary Glossary 8 PROFIBUS Networks SIMATIC NET 6GK1970 5CA20 0AA1 Release 2 05 2000 ...