Lenze E84Dxxxx - Manual (Page 17)

Communication manual 8400 protec PROFIBUS
Installation
Specification of the bus cable
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EDS84DPBUS EN 2.0 - 09/2010
4.2 Specification of the bus cable
Please follow the specifications of the PROFIBUS user organisation (PNO) for bus cables:
Bus cable length
The bus cable length depends on the baud rate used:

Tip!
For high baud rates we recommend to consider the application of optical fibres.
Advantages of optical fibres:
• External electromagnetic interferences on the transmission path remain
ineffective.
• Bus lengths of several kilometres are also possible with higher baud rates.
The bus length is ...
– independent of the baud rate;
– dependent on the optical fibre used.
Area Values
Cable resistance 135 ... 165 Ω/km, (f = 3 ... 20 MHz)
Capacitance per unit length ≤ 30 nF/km
Loop resistance < 110 Ω/km
Core diameter > 0.64 mm
Core cross-section > 0.34 mm 2
Cores Double twisted, insulated and shielded
Baud rate Length
9.6 ... 93.75 kbps 1200 m
187.5 kbps 1000 m
500 kbps 400 m
1500 kbps 200 m
3000 ... 12000 kBit/s 100 m

Note!
The baud rate depending of the data volume, cycle time and number of stations
should only be selected as high as required for the application.