Siemens SIMATIC RF600 System Manual page 88

RF600 system planning
4.7 Guidelines for electromagnetic compatibility (EMC)
Interference source
High-frequency appliances
Transmitter
(e.g. service radio)
Ground or reference potential
difference
Operator
Power cable
High-voltage cable
What interference can affect RFID?
Interference source
Switched-mode power supply Interference emitted from the
Interference injected through
the cables connected in
series
HF interference over the
antennas
Coupling paths
A coupling path has to be present before the disturbance emitted by the interference source
can affect the system. There are four ways in which interference can be coupled in:
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Interference results from
Circuit
Antenna
Voltage difference
Static charge
Current flow
Voltage difference
Cause
current infeed
Cable is inadequately
shielded
The reader is not connected
to ground.
caused by another reader
System Manual, 05/2012, J31069-D0171-U001-A13-7618
Effect on the interference sink
Electromagnetic field
Electromagnetic field
Transient currents
Electrical discharge currents, electrical
field
Electrical and magnetic field, system
disturbance
Electrical field
Remedy
Replace the power supply
Better cable shielding
Ground the reader
Position the antennas further
•
apart.
Erect suitable damping materials
•
between the antennas.
Reduce the power of the readers.
•
Please follow the instructions in the
Installation guidelines/reducing
section
the effects of metal
SIMATIC RF600