Safe Stop 2 Extended Stop And Retract (Ss2Esr) - Siemens SINAMICS S120 Function Manual

4.2.7.2

Safe Stop 2 Extended Stop and Retract (SS2ESR)

Unexpected axis motion
When function SS2ESR is active, during the delay time (p9554) the speed follows the
setpoint issued from the higher-level control system. As a consequence, unexpected axis
motion is possible, which can lead to severe injury and death.
• Prevent persons from entering the danger zone of the machine or system during the
Figure 4-10
In principle, Safe Stop 2 Extended Stop and Retract (SS2ESR) functions in exactly the same
way as SS2 described in the previous sections. Note, however, the following differences:
Differences between "Safe Stop 2 with OFF3" and SS2ESR
● If SS2ESR with external stop is selected, the drive does not brake the motor
automatically, but instead follows the defined speed setpoint: This can also result in fast
retraction motion.
● During the delay time p9554, the brake ramp (SBR) and the acceleration (SAM) are not
monitored, and there is no standstill detection.
● SOS becomes active after the delay time p9554 has expired. If function SS2ESR is
active, the higher-level control system must define the speed setpoint such that the motor
is stopped no later than after the delay time p9554 has expired.
● To enable SS2ESR, set p9501.4 = 1.
● PROFIsafe control word S_STW2.29 selects function SS2ESR. PROFIsafe S_STW2.29
is contained in telegrams 31, 901, 902 and 903.
● PROFIsafe status word S_ZSW2.27 indicates whether function SS2ESR is active.
PROFIsafe status word S_ZSW2.27 is contained in telegrams 31, 901, 902 and 903. The
associated diagnostics parameter is r9722.27. In the "Safety Info Channel," status word
S_ZSW3B.12 indicates whether the SS2ESR function is active. The associated
diagnostics parameter is r10234.12.
Safety Integrated
Function Manual, 12/2018, 6SL3097-5AR00-0BP1
WARNING
delay time (p9554), for example, by keeping protective devices closed and interlocked.
Selecting function SS2ESR
Description of Safety Integrated functions
4.2 Safety Integrated Extended Functions
109