Siemens SINUMERIK 840D sl Function Manual page 199

03.06
Limitations and constraints
The user must take into consideration the following points regarding the functioning
of the crosswise data comparison:
S Both channels (NCK/PLC) must execute the same logic.
S Do not implement any response sequences or sequence controllers that are
externally controlled using short input pulses. This is because short pulses of
this type may only be sent and processed in one channel because of sampling
effects.
S Unused inputs/outputs/markers of the SPL must be assigned the default value
= 0; single-channel use of individual bits for non-safety relevant purposes is not
permissible.
S External STOPs must be enabled (they are also used internally) and can be
extracted from the SPL if required. The "external STOP A" must be parameteri-
zed at the SPL interface for all safety axes using MD
$MA_SAFE_EXT_STOP_INPUT[0]. If this condition is not fulfilled, then Alarm
27033 is output.
S Crosswise data comparison checks whether the "commissioning phase" has
been completed. If errors are detected in the crosswise data comparison, a
"STOP D/E" is triggered on the NCK and drive depending on this criterion. If the
commissioning phase has not been completed after booting, Alarm 27095 "SPL
protection not activated" is repeatedly displayed (every 3 hours).
Machine
HW
PROFI–
inputs/
BUS DP
outputs
Process
Fig. 7-19 Communications between the NCK-drive-PLC components
© Siemens AG, 2006. All rights reserved
SINUMERIK 840D sl/SINAMICS S120 SINUMERIK Safety Integrated (FBSI sl) – 03.2006 Edition
NCK monitoring channel
external
SGEs/SGAs
NCK signal processing
NCK
signal
process
ing
Crosswise result and
PROFIsafe
data comparison
driver:
PLC
signal
process
ing
PLC signal processing
Drive monitoring channel
Connecting Sensors/Actuators
7.3 Safe programmable logic (SPL)
internal
SGEs/SGAs
Interface
NCK
SGE/SGA
signals
Crosswise result and
data comparison
Drive
SGE/SGA
signals
Interface
Axis/spindle DB
System
Comparator
data
Comparator
data
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