Safety Functions Integrated In The System/Drive; Safe Standstill (Sh) - Siemens SINUMERIK 840D sl Function Manual

Safety functions integrated in the system/drive

7.1

Safe standstill (SH)

Note
This chapter describes the safety function safe standstill (SH), controlled from the safety-
related motion monitoring functions. The function is based on the safety functions STO/SBC
of the drive.
The safety functions STO, SBC and SS1, integrated in the drive and controlled via the drive
terminals, are described in Chapter "Safe Torque Off (STO) (Page 58)". Control via terminals
and from the motion monitoring functions is in parallel and can be used independently of one
another.
A STOP A/STO initiated in the drive (i.e. a system error in the drive or STO/SBC/SS1 selection
via terminal) is however not available as two-channel SGA "STOP A/B active" for the safety-
related motion monitoring functions. There is only a single-channel signal "pulses cancelled"
present.
Description
The safe standstill function is based on the pulse cancellation function integrated in the Motor
Modules of the SINAMICS S120 (start inhibit).
There are two switch-off signal paths that are independent of one another, which ensure that
when a component fails, the drive is always brought into a safe condition.
The safe standstill function safely disconnects the energy feed to the motor in the event of a
fault or in conjunction with a machine function.
The following must be carefully observed when controlling/energizing SH from the motion
monitoring functions.
● The safety functions STO/SBC/SS1 integrated in the drive are, corresponding to the
description in Chapter "Safety Functions integrated in the drive (Page 51)", fully effective
(parameters, alarms etc.). The standard pre-assignment (default setting) of the associated
parameters is generally sufficient in the context of the motion monitoring functions.
● The safety function STO integrated in the drive does not have to be explicitly enabled; this
is implicitly enabled by enabling the motion monitoring functions (p9501 < > 0). However,
if the safety function SBC integrated in the drive is to be additionally activated when
selecting STO, then this must be explicitly enabled.
● The PROFIsafe drive address must be set.
Safety Integrated
Function Manual, 12/2017, 6FC5397-4BP40-6BA1
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