Siemens SINUMERIK 840D sl Function Manual page 121

03.06
S Acknowledgement for an internally initiated STOP A:
An unintentional restart is prevented for STOP A. The error can only be ac-
knowledged from the drive and control using a power on.
SGA STOP A/B active
This signal indicates that STOP A/B is active.
0 signal:
1 signal:
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.
SGE de-select external STOP A
"Pulse cancellation" can be requested and executed using this SGE.
The safe functions currently active (SG/SBH/SN/SE) are not influenced by this
SGE.
If one of the currently active limits is violated, an appropriate alarm is initiated. The
associated shutdown response cannot be activated because the pulses have al-
ready been cancelled. As soon as the stop request is cancelled via the SGE "de-
select ext. STOP A" any queued shutdown responses become active.
If a stop request is active, SGA "STOP A/B is active" is set in the same way as it
would be for an internally initiated STOP A.
The MD 36977: $MA_SAFE_EXT_STOP_INPUT[0] is used to define the selection/
de-selection of the external brake request, in this case, "de-select external STOP
A" (SH, pulse cancellation).
© Siemens AG, 2006. All rights reserved
SINUMERIK 840D sl/SINAMICS S120 SINUMERIK Safety Integrated (FBSI sl) – 03.2006 Edition
Safety Functions Integrated in the System/Drive
STOP A/B is not active.
STOP A/B is active.
6.3 Safe stops A-F
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