Siemens SIMATIC ET 200AL System Manual page 179

Connecting
5.4 Connecting IO-Link I/O modules to functional ground
Mounting
To connect IO-Link I/O modules to functional ground, proceed as follows:
1. Drill two fastening holes.
2. Strip the grounding cable.
3. Fasten the cable lug to the grounding cable.
4. Screw the module and the cable lug with the 4 mm fastening screws using a torque of
1.2 Nm.
The figure below shows how to connect the functional ground.
Figure 5-5
Note
Grounding in the case of a non-conductive mounting surface
Make sure there is a low-impedance connection between the module and functional ground.
Reference
You will find more information on installing the modules in the section Mounting modules
(Page 19).
36
Connecting the functional ground
IO-Link I/O modules
System Manual, 08/2021, A5E48755395-AB