Siemens SINUMERIK 840D Description Of Functions page 201

11.03
3.13 Behavior of Safety Integrated when the drive bus fails (from SW 6.4.15)
3.13.5 SGE/SGA processing in the PLC
The SGE/SGA processing in the PLC must always be available in order to
logically combine the 611digital SGA and to output this to the periphery or
read-in the peripheral signals and distribute these to the 611digital SGE.
Without NCK-SPL, they correspond to the assignment of the SGA/SGE to the
digital input/output modules that is made in the NCK using the appropriate
machine data.
With NCK-SPL, the PLC-SPL is the 2nd channel of the SPL; the results are
compared between the NCK and PLC.
The SGE that are read-in are not effective as they cannot be transferred to the
611digital monitoring channel via the faulted drive bus.
When processing the SGA in the PLC, the 611digital SGA are left in the same
state as before the drive bus failed.
Due to the missing sign-of-life character in the SGE/SGA data transfer, the PLC
will detect a fault at the latest after 2 s. However, at this instant in time, the
pulses would already have been cancelled after the expiration of
$MN_SAFE_PULSE_DIS_TIME_BUSFAIL or the appropriate drive machine
data.
3.13.6 Limitations
An ESR executed autonomously in the drive when the drive bus fails is only
possible if the pulse enable is output at terminal 663 via the local outputs on the
NCU. The DMP modules themselves are connected to the same drive bus and
when the drive bus fails, they automatically clear their outputs.
When using the NCK-SPL, the input quantities of the SPL should also come
from the local inputs on the NCU and/or from the PROFIsafe peripherals. The
reason for this is that the input quantities of the DMP modules remain at the
same state at the instant that the bus failed. If an Emergency Stop is
implemented using the SPL, when considering the maximum response time up
to pulse cancellation, the delay time in
$MN_SAFE_PULSE_DIS_TIME_BUSFAIL must be taken into account.
3.13.7 Examples
Example 1 The following parameterization ensures that when the drive bus fails there is
200 ms time for an ESR executed autonomously in the drive before the pulses
are cancelled. The SG stages for personnel protection are defined differently in
the individual axes.
$MN_SAFE_PULSE_DIS_TIME_BUSFAIL = 0.2
; Parameterization for the X axis (AX1)
; pulses are immediately cancelled in all SG stages, STOP D is initiated when
; the SG is exceeded
$MA_SAFE_VELO_STOP_MODE[AX1] = 3
; Parameterization for the Y axis (AX2)
; pulses are not immediately cancelled in all SG stages, STOP D is initiated
; when the SG is exceeded
$MA_SAFE_VELO_STOP_MODE[AX2] = 13
© Siemens AG 2003 All Rights Reserved
SINUMERIK 840D/SIMODRIVE 611 digital SINUMERIK Safety Integrated (FBSI) - Edition 11.03
3 Safety-Related Functions
3-201