Siemens SINUMERIK 840D sl Function Manual page 138

Safety Functions Integrated in the System/Drive
6.3 Safe Stops A–F
The NC–controlled ESR is initiated by writing to the system variable
$AC_ESR_TRIGGER=1 (also see /FB3/, M3 "Axis coupling and ESR"). To obtain
the criteria for initiating, the following SI system variables are used:
$VA_STOPSI:
Axial system variable that contains the present stop.
For a value of 4, a Stop E is active for this axis.
$A_STOPESI:
Global system variable that displays a value not equal to 0 to indicate that a Stop E
is active on one of the axes. This variable saves the user having to search through
all of the axes.
SGE deselect external STOP E
When a stop request is active, the SGA "STOP E is active" is set.
MD 36977: $MA_SAFE_EXT_STOP_INPUT[3] defines the selection/deselection of
the external braking request, in this case "deselect external STOP E" (extended
stopping and retraction plus path braking).
Note
STOP E only produces a different response than STOP D if the user has
configured the ESR function – extended stop and retract – and initiation of the
ESR is programmed depending on $VA_STOPSI or $A_STOPESI.
If ESR is not active, the STOP E behaves like a STOP D. However, if the ESR
configuration is incorrect, there is a delay of up to 2 IPO cycles compared to
STOP D until the braking operation is initiated. Possible causes:
S The initiation of the ESR as static synchronous action does not take into
account the system variables $VA_STOPSI or $A_STOPESI.
S ESR is neither parameterized nor enabled.
S For individual PLC controlled axes, only the axis–specific ESR is used via
$AA_ESR_TRIGGER. This trigger may be used in addition to the
channel–specific trigger.
For other incorrect ESR programming, a delay by the time entered in
$MC_ESR_DELAY_TIME1 and $MC_ESR_DELAY_TIME2 is possible. After these
times have expired, braking is initiated at the current limit. Possible cause:
S The retraction position cannot be reached within the specified time.
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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