• Feed the cabling into the cabinet from one side only and, if possible, on one level only.
• 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.
4.6.4
Electromagnetic interference
Three components have to be present for interference to occur in a system:
• Interference source
• Coupling path
• Interference sink
e.g. connecting cable
Interference source
(device emitting
interference)
Coupling path
e.g. drive unit
e.g. reader
Interference sink
(device affected by
interference)
Figure 4-9
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.
Planning the RF300 system
4.6 Guidelines for electromagnetic compatibility (EMC)
SIMATIC RF300
System Manual, 02/2021, C79000-G8976-C345-09
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