Safety Integrated Basic Functions; Safe Torque Off (Sto) - Siemens Sinamics S110 Function Manual

Safety Integrated Functions

8.4 Safety Integrated Basic Functions

8.4 Safety Integrated Basic Functions
Note
You can ask your local sales office regarding the PFH values of the individual safety
functions (also refer to the Section "Probability of failure of safety functions").
8.4.1

Safe Torque Off (STO)

In conjunction with a machine function or in the event of a fault, the "Safe Torque Off" (STO)
function is used to safely disconnect the torque-generating motor power supply.
The following is executed when "Safe Torque Off" is selected:
● Each monitoring channel triggers safe pulse suppression via its switch-off signal path.
● A motor holding brake is closed (if connected and configured).
When the function is selected, the drive unit is in a "safe status". The Switching On Inhibited
status prevents the drive unit from being restarted.
The integrated two-channel pulse suppression is the basis for this function.
Functional features of "Safe Torque Off"
● This function is integrated in the drive; this means that a higher-level controller is not
● The function must be enabled via parameter.
● When the "Safe Torque Off" function is selected:
● Extended acknowledgment:
352
required.
– The motor cannot be started accidentally.
– The pulse suppression safely disconnects the torque-generating motor power supply.
– The power unit and motor are not electrically isolated.
If STO is selected/deselected (and p9307.0/p9507.0 = 1 are set), safety messages, in
addition to fault messages, are also canceled automatically.
Function Manual, 01/2011, 6SL3097-4AB10-0BP3
Function Manual