here is the cable spec from profibus.com
The PROFIBUS standard defines two variations of the bus cable. However it is recommended to use cable Type A in all new installations.
Type A is especially recommended for high transmission speeds (>500 kBaud) and permits doubling of the network distance in comparison to Type B.
Technical specification:
Impedance: 35 up to 165 Ohm at frequencies from 3 to 20 Mhz.
Cable capacity: < 30 pF per meter.
Core diameter: > 0,34 mm2, corresponds to AWG 22.
Cable type: twisted pair cable. 1x2 or 2x2 or 1x4 lines.
Resistance: < 110 Ohm per km.
Signal attenuation: max. 9 dB over total length of line section.
Shielding: CU shielding braid or shielding braid and shielding foil
Max. Bus length: 200 m at 1500 kbit/s, up to 1,2 km at 93,75 kbit/s. Extendable by repeaters.
The PROFIBUS standard defines two variations of the bus cable. However it is recommended to use cable Type A in all new installations.
Type A is especially recommended for high transmission speeds (>500 kBaud) and permits doubling of the network distance in comparison to Type B.
Technical specification:
Impedance: 35 up to 165 Ohm at frequencies from 3 to 20 Mhz.
Cable capacity: < 30 pF per meter.
Core diameter: > 0,34 mm2, corresponds to AWG 22.
Cable type: twisted pair cable. 1x2 or 2x2 or 1x4 lines.
Resistance: < 110 Ohm per km.
Signal attenuation: max. 9 dB over total length of line section.
Shielding: CU shielding braid or shielding braid and shielding foil
Max. Bus length: 200 m at 1500 kbit/s, up to 1,2 km at 93,75 kbit/s. Extendable by repeaters.