Siemens SINAMICS S120 Function Manual page 30

Basic Functions
3.1 Safe Torque Off (STO)
● The status of the "Safe Torque Off" function is displayed using parameters.
Enabling the "Safe Torque Off (STO)" function
The "Safe Torque Off" function is enabled via the following parameters:
NOTICE
It is not possible to activate the control via TM54F and PROFIsafe at the same time.
● STO via terminals:
● STO via TM54F (only with "Extended Functions" option):
● STO via PROFIsafe (only with "Extended Functions" option):
Selecting/deselecting "Safe Torque Off"
The following occurs when "Safe Torque Off" is selected:
● Each monitoring channel triggers safe pulse suppression via its switch-off signal path.
● A motor holding brake is applied (if connected and configured).
The following occurs when "Safe Torque Off" is de-selected:
● Each monitoring channel cancels safe pulse suppression via its switch-off signal path.
● The safety prompt "Apply motor holding brake" is canceled.
● Any pending STOP F or STOP A commands are canceled (see r9772/r9872).
Note
If "Safe Torque Off" is de-selected and selected again through one channel within the
time in p9650/p9850, the pulses are canceled but a signal is not output.
If you want a message to be displayed in this case, however, you have to reconfigure
N01620/N30620 via p2118 and p2119 as an alarm or fault.
30
CAUTION
If two power transistors in the power unit (one in the upper and one offset in the
lower inverter bridge) fail at the same time, this can cause a momentary movement.
The maximum movement can be:
Synchronous rotary motors: max. movement = 180° / no. of pole pairs
Synchronous linear motors: max. movement = pole width
– p9601.0 = 1, p9801.0 = 1
– p9601.2 = 1, p9801.2 = 1
– p9601.3 = 0, p9801.3 = 0
– p9601.2 = 1, p9801.2 = 1
– p9601.3 = 1, p9801.3 = 1
Function Manual, (FHS) , 07/2007 Edition, 6SL3097-2AR00-0BP0
Safety Integrated