Possible Paths Of Electromagnetic Interference - Siemens CPU 313C Hardware And Installation Manual

 3URWHFWLRQ DJDLQVW (OHFWURPDJQHWLF ,QWHUIHUHQFH
 %DVLF 3RLQWV IRU 6\VWHP ,QVWDOODWLRQV &RQIRUPLQJ ZLWK (0&
5HTXLUHPHQWV
'HILQLWLRQ (0&
EMC (electromagnetic compatibility) describes the capability of electrical
equipment to operate free of errors in a given electromagnetic environment,
without being subject to external influence and without influencing external devices
in any way.
,QWURGXFWLRQ
Although your S7-300 and its components are developed for an industrial
environment and high electromagnetic compatibility, you should draw up an EMC
installation plan before you install the controller under consideration of all possible
interference sources.
3RVVLEOH HIIHFWV RI LQWHUIHUHQFH
Electromagnetic noise can influence a PLC in various ways:
• Electromagnetic fields having a direct influence on the system
• Interference via bus signals (PROFIBUS DP etc.)
• Interference coupling via the system wiring
• Interference influencing the system via the power supply and/or protective
ground
The figure below shows the likely paths of electromagnetic interference.
Bus signal
Figure 12-1 Possible paths of electromagnetic interference
S7-300 Automation System, Hardware and Installation: CPU 31xC and CPU 31x
A5E00105492-03
Electromagnetic
fields
PS CPU SM SM SM SM SM SM SM SM
Protective earth Power supply module
$SSHQGL[
Process wiring
12-3