Siemens SINAMICS S120 Function Manual page 82

Safety Integrated Extended Functions
5.7 Safe Speed Monitor (SSM)
In addition, the output signal for SSM can be smoothed by means of a PT1 filter by setting a
filter time p9345/9545.
During safe motion monitoring, the hysteresis and filtering functions can be activated or
deactivated jointly using the enable bit p9301.16 (Motor Modules) and p9501.16 (CU). In the
default setting, the functions are deactivated (p9301.16/p9501.16 = 0).
NOTICE
Exception
The activated "hysteresis and filtering" function is evaluated as activated monitoring
function and, after a STOP F, also results in a subsequent STOP B/STOP A response.
The following diagram shows the characteristic of the safe output signal SSM when the
hysteresis is active:
Figure 5-7
Due to the hysteresis, the safe output signal for SSM can also lie above the parameterized
velocity limit at 1.
Note
When the hysteresis and filtering are activated with output signal SSM, the axes behave in a
time-delayed manner. This is a characteristic of the filter.
82
Safe output signal for SSM with hysteresis
Function Manual, (FHS), 11/2009, 6SL3097-4AR00-0BP0
Safety Integrated