Siemens SINAMICS S120 System Manual page 219

Withdrawing the power enable (power inhibit)
When the power enable is withdrawn, the switch for the shutoff valve is opened and the
shutoff valve closes.
Note
Using a central shutoff valve
If there is only one central shutoff valve, you must logically interconnect the signals (e.g.
using the PLC), so that the central shutoff valve is triggered when the power is inhibited. To
prevent faults at the other axes, it must be ensured that all axes whose pressure is supplied
via this shutoff valve also receive the power inhibit command when the central shutoff valve
is triggered.
If each axis has its own dedicated shutoff valve, connect the shutoff valve with the "shutoff
valve" output of the associated axis.
Hydraulic Drive
System Manual, 04/2015, 6SL3097-4BA00-0BP1
Hardware
6.2 Interfaces
219