Siemens SIMATIC NET PROFIBUS manual Installation of the Profibus Festoon Cable Schematic

Passive Components for RS-485 Networks

Properties

The festoon cable has the following properties:

SThe outer sheath contains halogens (PVC)

SConditionally resistant to mineral oil and greases

SResistant to UV radiation

SSmall bending radii both during installation and operation

SDue to the smaller Cu cross-section of the inner conductors, the d.c. loop resistance and the HF attenuation are somewhat higher which means reduced segment lengths.

SThe sheath material is flame-retardant complying with VDE 0472 T804 test type B.

Uses

The LAN cable for festoons is designed for at least 5 million bending cycles at the specified bending radius and at a maximum acceleration of 4 m/s2.

Note

During installation and operation, all the mechanical restrictions involving the cable such as bending radii, tensile load etc. must be adhered to.

Example of installation:

Stopper
Lead runner	Runner	Kink protection	Clip

Pulling cord

to provide strain relief for the cable

Figure 4-10 Installation of the PROFIBUS Festoon Cable (Schematic)

Segment Lengths

Due to the increased loop resistance, somewhat shorter segment lengths are permitted at low transmission rates (see Table 3.1). At transmission rates ≥ 500 Kbps, the trailing cable has the same values as the standard LAN cable.

PROFIBUS Networks SIMATIC NET	4-19
6GK1970-5CA20-0AA1 Release 2 05/2000