Connecting 
  5.2 Networking 
SIMOTION C 
Operating Instructions, 02/2012 
125 
Greater cable lengths 
You need to install RS485 repeaters for segments requiring cable lengths longer than the 
allowed length. The maximum possible cable length between two RS 485 repeaters 
corresponds to the cable length of a segment (see the previous table). 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. This is true even if the RS 485 repeater is not assigned its 
own PROFIBUS address. 
5.2.3  Network components for a PROFIBUS subnet 
PROFIBUS cable 
We can offer you e.g. the following PROFIBUS cables:      
Table 5- 9  PROFIBUS cable 
Cables  Order no. 
PROFIBUS cable  6XV1 830-0EH10 
PROFIBUS direct-buried cable  6XV1 830-3FH10 
PROFIBUS drum cable  6XV1 830-3EH10 
Properties of the PROFIBUS cable 
The PROFIBUS cable is a two-core, twisted, and shielded cable with the following features: 
Table 5- 10  Properties of the PROFIBUS cable 
Features  Values 
Characteristic impedance  Approx. 135 to 160 Ω (f = 3 to 20 MHz) 
Loop resistance  ≦ 115 Ω/km 
Effective capacitance   30 nF/km 
Damping  0.9 dB/100 m (f = 200 kHz) 
Permissible conductor cross-section  0.3 mm
2
 to 0.5 mm
2
 
Permitted cable diameter  8 mm ± 0.5 mm