Siemens Sinumerik 840D sl Function Manual page 110

Safety functions integrated in the system/drive
6.1 Safe standstill (SH)
-- The safety function STO integrated in the drive does not have to be explicitly
enabled; this is implicitly enabled by enabling the motion monitoring func-
tions (p9501 < > 0). If the safety function SBC integrated in the drive is to be
additionally activated when selecting STO, then this however must be expli-
citly enabled.
-- The PROFIsafe drive address must be set.
Warning
!
If the safe standstill function or "STOP A" is activated, the motor can no longer
generate any torque. This is the reason that potentially hazardous motion can
occur, e.g. for the following:
S When an external force acts on the drive axes
S Vertical and inclined axes without weight equalization
S Axes that are moving (coasting down)
S Direct drives with low friction and low self--locking
S Notching torques (depending on the motor type, bearing design and friction
characteristics, up to half a pole pitch in a direction that cannot be predicted).
Possible hazards must be clearly identified using a risk analysis that must be
carried out by the manufacturer. With an assessment, based on this risk analysis,
it should be defined as to which additional measures are required, e.g. external
brakes.
Features
The main features of the safe standstill function are as follows:
S The motor cannot be started unintentionally or accidentally
S The energy feed to the motor is safely disconnected
S The Motor Module and motor are not electrically isolated from one another
Selecting/deselecting SH
The safe standstill function corresponds to an external STOP A. This makes it pos-
sible to explicitly select SH, not only using internal events (STOP A when a limit
value is violated), but also via SGE.
S Safe standstill is activated after a STOP A.
S Safe standstill is automatically activated from every monitoring channel when
testing the shutdown paths.
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SINUMERIK 840D sl/SINAMICS S120 SINUMERIK Safety Integrated (FBSI sl) - - 10.2015 Edition
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