14.4.3 Requirements for PROFIBUS Link
Cables used in PROFIBUS are shielded twisted pair cables. The shielding is able
to improve electromagnetic compatibility (EMC) ability. Unshielded twisted pair
cable may be used if there is less electromagnetic interference (EMI). Impe-
dance of the cable should be within 100...200 Ω. Cable capacity (among con-
ductors) should be < 60 pF/m, and conductor cross section should be ≥ 0.22 (24
AWG). Two kinds of cables are used for PROFIBUS with detail definitions stated
in table below.
Cable data
Type A
Type B
Impedance
135...165 Ω (f = 3...20 MHz)
100...130 Ω (f > 100 kHz)
Capacity
< 30 pF/m
< 60 pF/m
Resistance
≤ 110 Ω/km
≤ 110 Ω/km
Conductor cross
section
≥ 0.34 (22 AWG)
≥ 0.22 (24 AWG)
Tab. 14-29: Type of PROFIBUS cable
Standard Siemens PROFIBUS cable is (MLFB) 6XV1830-0EH10 (Type
A), and connector is 6ES7972-0BA12-0XA0.
14.4.4 Relationship between Communication Rate and Cables
Relationship between communication rate and cable length is described in table
below.
Baud rate
Maximum length for each cable in [m]
(Type A)
Maximum length for each cable in [m]
(Type B)
9.6...93.75 kbps
1,000
1,000
187.5 kbps
1000
600
500 kbps
400
200
1.5 Mbps
200
200
3...12 Mbps
100
100
Tab. 14-30: Relationship between communication rate and cable length
Bosch Rexroth AG
Communication
EFC x610 Series
276/389
DOK-RCON03-EFC-X610***-IT05-EN-P
