Siemens SIMATIC NET PROFIBUS, Owner'S Manual

Page: 69 / 490

Configuring Networks
3-3
PROFIBUS Networks SIMATIC NET
6GK1970-5CA20-0AA1 Release 2 05/2000
Note
The power supply to terminating resistors must not be interrupted by turning off
the DTE or repeater or by unplugging the bus connector or tap line. If the power
supply to the terminating resistors cannot be guaranteed, the PROFIBUS
terminator must be used.
3.1.1 Segments for Transmission Rates up to a Maximum of 500 Kbps
Transmission Rates up to a Maximum of 500 Kbps
The following maximum segment lengths can be implemented with the SIMATIC
NET PROFIBUS LAN cables:
Table 3-1 Possible Segment Lengths
Segment Length for Cable Type
Transmission Rate
in Kbps
– FC Standard Cable
– FC Robust Cable
– FC FRNC Cable
– FC Food Cable
– FC Underground Cable
– SIENOPYR–FR Marine Cable – FC Trailing Cable
– PROFIBUS Flexible Cable
– PROFIBUS Festoon Cable
9.6 1000 m 900 m
19.2 1000 m 900 m
45.45 1000 m 900 m
93.75 1000 m 900 m
187.5 1000 m 700 m
500 400 m 400 m
The maximum permitted number of bus attachments (DTEs, repeaters, OLMs,
BT12 M,...) to one segment is 32.