Siemens SINAMICS S120 Function Manual page 309

● 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).
Drive Functions
Function Manual, (FH1), 07/2007 Edition, 6SL3097-2AB00-0BP4
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
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.
Safety Integrated basic functions
9.3 Safe Torque Off (STO)
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