Siemens S5-135U/155U - Manual (Page 29)

3-3
System Manual
C79000-G8576-C199-06
Depending on the propagation medium (conducted or non-conducted
interference) and distance from the source, interference can be picked up by
the programmable controller via different coupling mechanisms.
A distinction is made between the following:
S
Direct coupling
S
Capacitive coupling
S
Inductive coupling
S
Radiated interference
Installation Guidelines