Cable specifications
TCD Electronics | Function Manual | Version: TCD_PROFI_S_EN_200326_E003
49
4.
Cable specifications
Recommended cable types
The PROFIBUS standard defines two variations of the bus cable: Cable type A and cable type B. It is
recommended to use cable Type A in all new installations.
Both types have cable shielding that guarantees adequate protection from electromagnetic
interference and thus the most reliable data transfer.
Type A
Cable structure
twisted pair, individual shield
Wire size
0.8 mm2 (AWG 18)
Loop resistance (DC)
44
Ω/km
Impedance at 31.25 kHz
100
Ω
± 20%
Attenuation at 39 kHz
3 dB/km
Capacitive asymmetry
2 nF/km
Envelope delay distortion (7.9 to 39 kHz)
1.7
μs/km
Shield coverage
90 %
Max. cable length (inc. spurs >1 m)
1900 m (6233 ft)
Tab. 22: Cable type A specifications
Overall cable length
The overall cable length is made up of the length of the main cable and the length of all spurs
(>1 m [3.28 ft]).
The maximum network expansion depends on the type of ignition protection and the cable specifications.
NOTE
If repeaters are used the maximum allowed cable length is doubled. Max. three repeaters are permitted
between user and master.
PROFIBUS transmission rate (kBit/s)
Cable length
9.6
1,200 m [4,000 ft.]
19.2
1,200 m [4,000 ft.]
45.45
1,200 m [4,000 ft.]
93.75
1,200 m [4,000 ft.]
187.5
1,000 m [3,300 ft.]
500
400 m [1,300 ft.]
1500
200 m [650 ft.]
3000
100 m [330 ft.]
6000
100 m [330 ft.]
12000
100 m [330 ft.]