Use only shielded data cables. The shield should be grounded at both ends.

A cable shield only grounded at one end can only protect from capacitively coupled interference and low-frequency disturbances (50 Hz hum).

Avoid parasitic currents flowing through the cable shields.

This can be done by installing current-carrying equipotential bondings.

Use only cables with braided shields.

Foil shields are not robust enough, cannot be contacted well and have poor HF properties.

Use only metallic or [metal]-plated plugs for shielded data cables.

Use only shielded cables for analog signals.

For small signals ground the shield only at one end.

Ground the cable shield directly with a clip when entering the control cabinet.

Do not cut the shield until the cable reaches the module connected.