Siemens SIMATIC ET 200AL System Manual page 182

Pin assignment of the sockets
The pin assignment of the sockets can be found in the equipment manuals of the I/O modules
(https://support.industry.siemens.com/cs/ww/en/ps/14247/man) in the section on pin
assignment and on the side surface of the module.
Y-cable
The Y-cable allows you to connect two actuators or sensors to the inputs or outputs.
The use of a Y-cable is recommended in particular if two channels are occupied per socket of
an I/O module. The Y-cable distributes the channels to two circular connectors.
The figure below shows the wiring of the Y-cable.
Figure 5-8
Sealing of unused sockets
To ensure IP65 or IP67 degree of protection, seal off all unused sockets with sealing caps.
Article numbers for accessories/spare parts.
You will find the article numbers in the Appendix in section Accessories/spare parts (Page 66).
See also
Interface modules (https://support.industry.siemens.com/cs/ww/en/ps/14246/man)
IO-Link I/O modules
System Manual, 08/2021, A5E48755395-AB
Wiring of the Y-cable
Connecting
5.5 Wiring
39