6.3 Safe Stops A- -F - Siemens Sinumerik 840D sl Function Manual

Safety functions integrated in the system/drive

6.3 Safe Stops A- -F

S Effect:
The drive is braked along the OFF3 ramp under closed--loop speed control and
brought into SBH.
S Alarm message for an internally initiated STOP C:
The alarm message "STOP C initiated" is output (see Chapter 10.2, "Alarms for
SINUMERIK 840D sl").
S Acknowledgment for an internally initiated STOP C:
An unintentional restart is prevented for a STOP C. The error can be acknowl-
edged using the NC--RESET key.
SGA "STOP C is active"
This signal indicates that STOP C is active.
0 signal:
1 signal:
It is possible that the stop for the NCK becomes effective one safety monitoring
clock cycle earlier than for the drive. This means that braking along the current
limit can become effective before the OFF3 ramp of the drive becomes effective.
In order to reduce the level of stress of the mechanical system of the machine
(if required) the braking torque can be reduced. To realize this, bit 4 "Torque limi-
ting active in motoring/regenerating mode" can be set in parameter p1400 and
parameter p1521 "Torque limit lower/regenerative" can be set to the required lower
torque. In this case, it should be noted that the braking distance (stopping
distance) of the axis is extended, and that the torque limiting is not only effective
for STOP C, but that generally, the dynamic response of the axis changes.
Alternatively, braking can be realized drive--based along the OFF3 ramp
(see Chapter 6.3.5 "Braking behavior for STOP B/C").
Note
Tracking operation becomes active when a STOP C is initiated.
SGE deselect external STOP C
If a stop request is active, SGA "STOP C is active" is set in the same way as it
would be for an internally initiated STOP C.
MD36977 $MA_SAFE_EXT_STOP_INPUT[1] is used to define the selection/de-
selection of the external braking request; in this case "deselect external STOP C"
(braking along the current limit or braking along the OFF3 ramp).
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STOP C is not active.
STOP C is active.
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