Ss2 With External Stop (Ss2E) - Siemens Sinamics S120 Function Manual

Description of Safety Integrated functions
4.2 Safety Integrated Extended Functions
4.2.8.2 SS2 with external s top (SS2E)
Danger to life t hrough unexpected axis movement
When function "Safe Stop 2 with external stop" (SS2E) is active, during the delay time
(p9553) 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.
• During delay time (p9553), avoid that persons enter the hazardous area of the machine
Image 4-4
With external stop, "Safe Stop 2" functions in principle exactly the same way as described in
the previous sections. Note, however, the following differences:
Dif ferences between "Safe Stop 2 with OFF3" and "SS2 with external stop (SS2E)"
● When SS2 is selected with external stop, the drive does not automatically brake the
motor, but instead, follows the specified speed setpoint.
● During delay time p9553, the brake ramp (SBR) and the acceleration (SAM) are not
monitored and there is no standstill detection.
● SOS becomes active after the delay time p9553 expires.
When function SS2E is active, the higher-level control must issue the speed setpoint so
that at the latest after delay time p9553 expires, the motor has come to a complete
standstill.
● In order to activate "Safe Stop 2 with external stop", set p9501.18 = 1.
● PROFIsafe STW2.28 selects function SS2E. PROFIsafe STW2.28 is included in
telegrams 30, 901 and 902.
● PROFIsafe ZSW2.28 indicates whether function SS2E is active. PROFIsafe ZSW2.28 is
included in telegrams 30, 901 and 902. The associated diagnostics parameter is
r9722.28.
In the "Safety Info Channel", status word S_ZSW3B.11 indicates whether function SS2E
is active. The associated diagnostics parameter is r10234.11.
Diagnostic parameters p9722.28 and p10234.11 are also set during an internal STOP D.
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or system, e.g. by keeping protective equipment closed.
Selecting function SS2E
Function Manual, (FHS), 07/2016, 6SL3097-4AR00-0BP6
Safety Integrated