Siemens SIMATIC NET SCALANCE XC-200 Series Operating Instructions Manual page 56

Connecting up
5.6 Functional ground
grounded at one defined point. Here, once again the grounding is implemented with the lowest
leakage resistance to ground in the vicinity of the power feed-in.
With automation components, functional ground also ensures interference-free operation of a
controller. Via the functional ground, interference currents coupled in via the connecting cables
are discharged to ground.
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Operating Instructions, 12/2017, C79000-G8976-C442-03
SCALANCE XC-200