Siemens SINUMERIK MC Commissioning Manual page 287

Settings
Setting
SSM with hysteresis
p9501.16
Filter time
p9545
Hysteresis
p9547
Speed limit
p9546
Feedback signal SSM active for pulse inhibit
(only in encoderless operation)
p9509.0
Safety Integrated (with SINAMICS S120)
Commissioning Manual, 02/2020, A5E46305916B AB
6.6 Configuring safety functions integrated in the drive
Meaning
Activates the "Hysteresis" and "Filter time" functions for SSM.
If the "SSM with hysteresis" function is enabled, the SSM function is evalu‐
ated as an active monitoring function, and after a STOP F, also results in a
subsequent STOP B / STOP A response.
Sets a filter time (PT1 filter) to smooth the output signal for SSM.
As filtering characteristic, for output signal SSM, a time-delayed SSM feed‐
back signal occurs for the axes.
Parameterizing hysteresis for SSM
In this way, a more stable SSM signal characteristic can be achieved at
velocities close to the "Velocity limit" (monitoring threshold).
The velocity (or speed) determined by both channels may differ as a maxi‐
mum by the difference between "Velocity/speed limit" and "Hysteresis". Oth‐
erwise, it would be theoretically possible that for SSM one channel returns a
HIGH signal and the other a LOW signal.
Take into account the following rule when parameterizing:
● Hysteresis p9547 ≤ 0.75 · velocity limit p9546
If actual value synchronization is enabled (Settings - encoder parameteriza‐
tion (Page 255)), then you must also comply with the following rule:
● "SI Motion slip speed tolerance" (p9549) ≤ hysteresis
Sets the velocity limit for the SSM feedback signal to detect standstill (n < nx).
If the velocity limit is fallen below, then the signal "Safe Speed Monitor feed‐
back signal active" (SGA n < n_x) is set.
The abbreviation SGA n < nx stands for the safety function required for
determining an output signal when a parameterizable velocity limit has been
undershot.
This value is also active for safety function SAM as "Shutdown velocity ac‐
celeration monitoring" - assuming that this shutdown velocity is parameter‐
ized with "0". In this case, the effects of Safe Acceleration Monitoring are
therefore restricted if a relatively high SSM velocity limit is set when using the
SS1 and SS2 stop functions.
Sets the response during pulse cancellation in encoderless operation.
For Safe Speed Monitor without encoder, after pulse cancellation the drive is
unable to determine the current velocity. 2 responses can be selected for this
operating state:
● The status signal (SSM feedback signal) indicates "0" (factory setting).
● The status signal (SSM feedback signal) is frozen. "Safe Torque Off"
(STO) is selected internally.
See also: Signal characteristic for setting "Feedback signal SSM for pulse
inhibit " (Page 150)
Commissioning and configuring
287