Basic Information On Electromagnetic Compatibility; Overview Of Possible Interference - Siemens SIMATIC ET 200AL System Manual

Basic information on electromagnetic compatibility

2.1

Overview of possible interference

Introduction
SIMATIC products and their components have been developed for use in industrial
environment and meet the legal EMC requirements (EMC - Electromagnetic Compatibility).
However, you still need to conduct an EMC assessment before installing your controller in
order to identify possible sources of interference and to include these in your considerations.
Electromagnetic compatibility
Electromagnetic compatibility describes the ability of an electrical device to function properly
in its particular electromagnetic environment. Neither the environment itself nor the electrical
device are influenced in an unacceptable manner.
Possible interference
Electromagnetic interference can influence an automation system in various ways. The most
significant interferences and their causes are as follows:
● Electromagnetic fields having a direct influence on the system
● Interference coupling caused by bus signals (for example, PROFINET)
● Interference influencing the system via the process wiring
● Interference which reaches the system via the power supply and/or protective ground
The figure below shows the likely paths of electromagnetic interference.
Figure 2-1
Designing interference-free controllers
Function Manual, 06/2014, A5E03461486-AB
Electromagnetic interference
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