Siemens SIMATIC NET PROFIBUS Owner's Manual page 224

Passive Components for Electrical Networks
Cable Lengths
The length of the transmission path on fiber-optic cables is not dependent on the
transmission rate.
Each node on the optical PROFIBUS network has repeater functionality so that the
following distance information relates to the distance between two adjacent,
interconnected PROFIBUS nodes in a bus topology.
The maximum cable length between two PROFIBUS nodes depends on the type
of fiber-optic cable used.
Table 7-7
Fiber-optic cable
SIMATIC NET
PROFIBUS
Plastic fiber-optic,
duplex cord
Plastic fiber-optic,
standard cable
PCF fiber-optic,
standard cable
Table 7-8
Fiber-optic cable
SIMATIC NET
PROFIBUS
Plastic fiber-optic,
duplex cord
Plastic fiber-optic,
standard cable
PCF fiber-optic,
standard cable
7-28
Permitted Cable Lengths in Networks with Integrated Optical Interfaces (Bus
Topology)
Maximum cable
lengths between two
nodes (in m)
Permitted Cable Lengths in an OLM Network
Maximum cable
lengths between two
nodes (in m)
For 1 Network (= 32
nodes) (in m)
50
50
300
For 1 Network (= 32
nodes) (in m)
50
80
400
PROFIBUS Networks SIMATIC NET
6GK1970-5CA20-0AA1 Release 2 05/2000
1550
1550
9300
1550
2480
12400