Siemens SIRIUS 3SK1

Note
If a basic unit is expanded on the right, the last output expansion must be terminated with a
device termination connector of the corresponding device.
If a basic unit is only expanded on the left, a device termination connector for 3SK1 safety relays
must be mounted below the basic unit.
6.2.2 Applications
The 3SK1 Advanced basic unit can be expanded on the input and output sides using 3ZY12
device connectors (connecting plugs) without any additional wiring outlay. When con󹪝guring
the system, it is important to ensure that input expansions are connected on the left and output
expansions/3RM1 Failsafe motor starters on the right of a basic unit.
System con󹪝guration
6.2 3ZY12 device connector
SIRIUS 3SK1 Safety Relays and 3RQ1 Positively-Driven Coupling Relays
Equipment Manual, 05/2021, A5E02526190021A/RS-AE/005 119