10
SI-PROFINET RT User Guide
Issue Number: 2
Avoid excessive bending during installation, the maximum recommended bending
radius is 10 times the cable diameter 75 mm (3.0 in).
Cabling issues are the single most frequent cause of network downtime.
•
Ensure cables are correctly routed i.e. not adjacent to high-power cables etc.
•
Wiring must be correct, and the connectors should be of industrial grade with metal
shielding.
•
Routers or switches must be of industrial and not ‘office’ quality, as they do not
provide the same degree of noise immunity as their industrial counterparts.
4.3
Cable
Copper cables should be shielded twisted pair (STP) and, as a minimum, meet TIA Cat
5e requirements and be certified for use on a PROFINET network. The coloring of the
outer sheath is not critical but should be consistent (where possible) to simplify system
maintenance and, preferably, for identification purposes comply with the standard
PROFINET coloring (yellow/green).
PROFINET copper cables are categorized into three different types, the actual type
used is mainly determined by the relevant application.
•
Type A
cables are designed for fixed installations where the cable is not subject to
any movement.
•
Type B
cables are designed for flexible installations where the cable can be subject
to occasional movement or vibration.
•
Type C
cables are designed for special applications where the cable will be subject
to frequent or continuous movement or vibration.
4.3.1 Cable properties
The properties for all three types of cables are similar, the only difference between the
three types are the size of the individual wires used.
Table 4-1 Cable properties
Special properties of some copper cables use flame retardant materials which can
reduce the maximum length of the cable to less than 100 m. For more information
please refer to the cable manufacturer's documentation.
NOTE
Impedance
100
Ω
±15
Ω
Loop resistance
<115
Ω
/km
Transmission rate
100 M Bit/s
Maximum length
100 m
Number of wires
4
Sheath color
Green
Insulation color
White, Blue, Yellow, Orange
Type A
Type B
Type C
Wire diameter
0.64 mm
0.75 mm
0.13 mm
Wire CSA
0.32 mm
2
(AWG 22/1)
0.36 mm
2
(AWG 22/7)
AWG 22/7
or
AWG 22/19
NOTE
