Siemens SINUMERIK MC Commissioning Manual page 120

Safety functions integrated in the drive
4.6 SS2
After the function has been selected, the delay time starts to expire - even if the function is
deselected during this time. In this case, after the delay time has expired, the SOS function is
briefly active. Afterwards, the drive may accelerate the motor back to the speed setpoint.
Interruption of the active SS2E function by functions SS1 and SS2
Figure 4-8
When selecting SS1, the drive brakes the motor along the OFF3 ramp and monitors the speed
using the SAM function. Function STO becomes active when the motor is at a standstill.
When selecting SS2, the drive also brakes the motor along the OFF3 ramp and monitors the
speed using the SAM function. Function SOS becomes active after time p9552.
Adaptation of the dynamic response for axes
For axes, the control system dynamically adapts the acceleration characteristic so that the axes
stop within the time specified in p9553 "SI Motion transition time STOP D to SOS". Therefore,
ensuring stopping with low associated stress on the machine.
If the STOP D time, parameterized in p9553 is used as basis to determine the braking time and
issue an alarm, this must be enabled by setting bit 2 in MD37950 $MA_SAFE_INFO_ENABLE.
When powering up, for all axes with SIC/SCC connection, where the bit to take into account the
stop D/SS2E transition times in the braking response (MD37950 $MA_SAFE_INFO_ENABLE,
bit 2) is set, the control system checks whether the braking time set in p9553 is sufficient for the
active acceleration characteristic of the axis. If the set braking time is too short, then alarm
22001 "Channel %1 block %2 axis %3: braking time %6 [s] longer than the stop D time. Reason:
%5" is output.
If the acceleration/deceleration behavior is changed, the axes brake for STOP D with the
shortest transition time of all path axes. Ideally, the transition times are set to identical values
in p9553 for all axes in an interpolation group.
Adaptation of the dynamic response for spindles
For spindles, the actual acceleration characteristic is not adapted. The control system checks
whether the braking time set in p9553 is sufficient for all spindle operating modes and
120
Interruption of function SS2E by functions SS1 (shown at the left) and SS2 (shown at the
right)
Safety Integrated (with SINAMICS S120)
Commissioning Manual, 02/2020, A5E46305916B AB