Siemens SINAMICS S120 Function Manual page 370

Safety Integrated basic functions
9.3 Safe Torque Off (STO)
3. Cancel the "switching on inhibited" and switch the drive back on.
4. Run the drives again.
Status for "Safe Torque Off"
The status of the "Safe Torque Off" (STO) function is displayed using the following
parameters:
Overview of important parameters (see SINAMICS S120/S150 List Manual)
● r9772 CO/BO: SI status (Control Unit)
● r9872 CO/BO: SI status (Motor Module)
● r9773 CO/BO: SI status (Control Unit + Motor Module)
● r9774 CO/BO: SI status (STO group)
As an alternative, the status of the functions can be displayed using the configurable
messages N01620 and N30620 (configured using p2118 and p2119).
Response time with the "Safe Torque Off" function
For the response times when the function is selected/deselected via input terminals, see the
table in "Response times".
Examples: Booksize
Assumption:
Safety monitoring clock cycle time CU (r9780) = 4 ms and
inputs/outputs sampling time (r0799) = 4 ms
t
R_typ
t
R_max
Overview of important parameters (see SINAMICS S120/S150 List Manual)
● p0799 CU inputs/outputs sampling time
● r9780 SI monitoring clock cycle (Control Unit)
● r9880 SI monitoring clock cycle (Motor Module)
Internal armature short-circuit with the "Safe Torque Off" function
The "Internal armature short-circuit" function cannot be selected at the same time as the
"STO" function. This is because selection of STO always initiates an OFF2 which in turn
deactivates the "Internal armature short-circuit function. The STO safety function has a
higher priority than the "Internal armature short-circuit" function, i.e. if STO is activated, it will
deactivate an internal armature short-circuit if one is currently active.
370
– 1/0 edge at input signal "ON/OFF1" (cancel "switching on inhibited")
– 0/1 edge at input signal "ON/OFF1" (switch on drive)
= 2 x r9780 (4 ms) + r0799 (4 ms) = 12 ms
= 4 x r9780 (4 ms) + r0799 (4 ms) = 20 ms
Function Manual, (FH1), 10/2008, 6SL3097-2AB00-0BP5
Drive functions