Siemens SINAMICS S150 - Page 100

Safety Integrated Extended Functions
6.8 Safe Speed Monitor (SSM)
Safety Integrated
100 Function Manual, 05/2010, A5E03264275A
The hysteresis for the SSM output signal is set in parameter p9347/p9547 "SI motion SSM
speed hysteresis n_x". In other words the SSM output signal can take on either state "1" or
state "0" - depending on the direction from the belt is reached.
If the maximum permissible velocity tolerance is overshot (i.e. one channel displays a
velocity less than p9546 - p9547, while the other channel displays a velocity greater than
p9546), a STOP F is issued. As an additional function, parameters p9347/p9547 are used to
define the maximum tolerance of the velocity actual values between the two channels.
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:
660RXWSXWVLJQDO
S
S SS SS
Q>PPPLQ@

Figure 6-7 Safe output signal for SSM with hysteresis
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.