Siemens SIMATIC ET 200AL System Manual page 45

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 particularly recommended when two channels are occupied for each
socket of an I/O device. The Y-cable distributes the channels to two circular connectors.
The figure below shows the wiring of the Y-cable.
Figure 5-10
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 97).
Distributed I/O system
System Manual, 02/2018, A5E31861578-AF
Wiring of the Y-cable
Connecting
5.6 Wiring
43