Siemens SINUMERIK 840D sl Function Manual page 114

Safety Functions Integrated in the System/Drive
6.1 Safe stop (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 explic-
itly 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
possible 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.
Warning
!
After the machine has been powered–up, the "safe standstill" function must always
be tested for all of the axes/spindles by testing the shutdown path using Safety
Integrated.
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SINUMERIK 840D sl/SINAMICS S120 SINUMERIK Safety Integrated (FBSI sl) – 05.2008 Edition
© Siemens AG 2008 All Rights Reserved
05.08