Wiring 2408
f
& 2404
f
PROFIBUS Communications Handbook
3-2 2408
f
and 2404
f
PROFIBUS Communications Handbook
Either of the two cable types detailed below can be used. Please note that the cable types A and B,
specified below, are NOT related to the wire numbers A and B in the above wiring diagram. Type A
is recommended as it allows higher speed and longer cable length.
Type A cable Type B cable
Characteristic
Impedance: 135 to 165Ω at a frequency of 3 to 20 MHz. 135 to 165Ω at a frequency of > 100 kHz
Cable
capacitance: < 30 pF per Metre typ. < 60 pF per Metre
Core diameter: max. 0.34 mm², corresponds to AWG 22 max. 0.22 mm², corresponds to AWG 24
Cable type: twisted pair cable. 1x2 or 2x2 or 1x4 lines twisted pair cable. 1x2 or 2x2 or 1x4 lines
Resistance: < 110 Ohm per km -
Shielding: Copper shielding braid or shielding braid and
shielding foil Copper shielding braid or shielding braid and
shielding foil
Belden B3079A meets cable A specifications, but there are other choices. For more information refer
to the ‘PROFIBUS Product Guide’ produced by the PROFIBUS User Group.
Maximum line length per segment
Baud rate (kbit/sec) 9.6 19.2 93.75 187.5 500 1500
Type A cable 1200m 1200m 1200m 1000m 400m 200m
Type B cable 1200m 1200m 1200m 600m 200m -