Siemens SINAMICS S120 Function Manual page 56

Safety Integrated Basic Functions
4.1 Safe Torque Off (STO)
Examples booksize
Assumption:
Safety monitoring clock cycle CU (r9780) = 4 ms and
inputs/outputs sampling time (r0799) = 4 ms
t
R_type
t
R_max
Internal armature short-circuit with the "Safe Torque Off" function
The function "internal armature short-circuit" can be configured together with the "STO"
function. However, only one of the two functions can be selected, as an OFF2 is also always
triggered when STO is selected. This OFF2 disables the function "Internal armature short-
circuit".
The "STO" safety function has the higher priority when simultaneously selected. If the "STO"
function is initiated, then an activated "internal armature short-circuit" is disabled.
Overview of important parameters (see SINAMICS S120/S150 List Manual)
● r9720.0...10 CO/BO: SI Motion control signals integrated in the drive
● r9722.0...15 CO/BO: SI Motion status signals integrated in the drive
● 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 (group STO)
● p0799 CU inputs/outputs sampling time
● r9780 SI Monitoring clock cycle (Control Unit)
● r9880 SI Monitoring clock cycle (Motor Module)
56
= 2 x r9780 (4 ms) + r0799 (4 ms) = 12 ms
= 4 x r9780 (4 ms) + r0799 (4 ms) = 20 ms
Function Manual, (FHS), 11/2009, 6SL3097-4AR00-0BP0
Safety Integrated