2.6.2 Functional Earth

The functional earth provides a stable zero-voltage reference point for device screening. The device casing and any additional shielding should be connected to the functional earth. In this way any electrostatic interference is diverted to earth rather than causing pickup in the device electronic circuits.

Some PROFIBUS devices feature a functional grounding terminal. Connect the grounding terminal of the PROFIBUS station to the system ground. The grounding terminal is identified by the symbol for grounding .

1. The Protective earth terminal is independent from this and must always be tied to the protective earth of the system..
   
   
2. For other devices, the grounding is carried out via the DIN-Rail. For this reason, you should also ground DIN-Rail.
   
   
3. Use copper cables with an appropriate cross section (> 2.5 mm²) for the grounding connection of the PROFIBUS stations. Grounding cables generally feature a green-yellow insulation. In some countries, the green-yellow identification is mandatory (green in the US).