Length Of Profibus Cables; Rules For The Laying Of Profibus Cables - Siemens SIMOTION D4 5-2 Series Commissioning And Hardware Installation Manual

3.7.3

Length of PROFIBUS cables

Cable lengths and baud rate
The baud rate determines the cable length of a subnet segment.
Table 3- 5
Baud rate
19.6 to 187.5 kbit/s
500 kbit/s
1.5 Mbit/s
3 to 12 Mbit/s
With isolated interface
1)
Longer cable lengths
If you must implement longer cable lengths than permitted in one segment, you must use
RS 485 repeaters. The maximum possible cable lengths between two RS 485 repeaters
correspond to the cable length of a segment. You can connect up to nine RS 485 repeaters
in series.
Note that an RS 485 repeater must be counted as a subnet node when determining the total
number of nodes to be connected, even if it does not have its own PROFIBUS address.
3.7.4

Rules for the laying of PROFIBUS cables

Laying of bus cable
During laying of the PROFIBUS cable, you must:
● Not twist the cable
● Not stretch the cable
● Not squeeze the cable
SIMOTION D4x5-2
Commissioning and Hardware Installation Manual, 02/2012
Permitted cable length of a subnet segment for specific baud rates
3.7 Connecting PROFIBUS/MPI
Max. cable length of a segment (in m)
1000
1)
400
200
100
Connecting
65