User's Manual

Table Of Contents
Planning the RF300 system
4.5 Guidelines for electromagnetic compatibility (EMC)
SIMATIC RF300
102 System Manual, 07/2016, C79000-G8976-C345-0x
Route the signal cables as close as possible to chassis surfaces.
Twist the feed and return conductors of separately installed cables.
Routing HF cables:
avoid parallel routing of HF cables.
Do not route cables through the antenna field.
Shielding for the cables
Shield the data cables and connect the shield at both ends.
Shield the analog cables and connect the shield at one end, e.g. on the drive unit.
Always apply large-area connections between the cable shields and the shielding bus at
the cabinet inlet and make the contact with clamps.
Feed the connected shield through to the module without interruption.
Use braided shields, not foil shields.
Line and signal filter
Use only line filters with metal housings
Connect the filter housing to the cabinet chassis using a large-area low-HF-impedance
connection.
Never fix the filter housing to a painted surface.
Fix the filter at the control cabinet inlet or in the direction of the source.
4.5.4
Propagation of electromagnetic interference
Three components have to be present for interference to occur in a system:
Interference source
Coupling path
Interference sink
Figure 4-11 Propagation of interference
If one of the components is missing, e.g. the coupling path between the interference source
and the interference sink, the interference sink is unaffected, even if the interference source
is transmitting a high level of noise.