Siemens SIMATIC NET PROFIBUS manual Cable Lengths, Fiber-optic cable

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	Permitted Cable Lengths in Networks with Integrated Optical Interfaces (Bus
	Topology)
Fiber-optic cable		Maximum cable	For 1 Network (= 32
SIMATIC NET		lengths between two	nodes) (in m)
	PROFIBUS	nodes (in m)
Plastic fiber-optic,		50	1550
duplex cord
Plastic fiber-optic,		50	1550
standard cable

PCF fiber-optic, standard cable

300

9300

Table 7-8	Permitted Cable Lengths in an OLM Network
Fiber-optic cable		Maximum cable	For 1 Network (= 32
SIMATIC NET		lengths between two	nodes) (in m)
	PROFIBUS	nodes (in m)
Plastic fiber-optic,		50	1550
duplex cord
Plastic fiber-optic,		80	2480
standard cable

PCF fiber-optic, standard cable

400

12400

7-28	PROFIBUS Networks SIMATIC NET
	6GK1970-5CA20-0AA1 Release 2 05/2000