Earth grounding provides protection from electrostatic discharge or other forms of electromagnetic interference (EMI).
Figure 1. Earth ground and power options

The power source determines the type of earth grounding you must perform:
- 2.1 (AC): Dedicated 24 V transformer required, with neither side of the transformer secondary tied to ground.
- 2.2 (DC): Polarity is not important as it uses an onboard diode bridge, with neither leg tied to ground.
- 2.3: Wall-mount AC adapter, FX-SC8XPS-0, instead of wiring 24 V to 2-position connector. Do not use the wall-mount AC adapter simultaneously with power wired 2-position connector.