Siemens SINUMERIK 840D sl Function Manual page 229

05.08
S System variables $A_OUTSI, $A_OUTSID, $A_OUTSE, $A_OUTSED,
$A_MARKERSI, $A_TIMERSI and $A_CMDSI are protected from being written
to by programs other than the NCK–SPL (/_N_CST_DIR/_N_SAFE_SPF). If an
error occurs, Alarm 17070 "Channel %1 block %2 data item write–protected" is
output.
S A reference checksum is calculated when booting by the NCK–SPL
(/_N_CST_DIR/_N_SAFE_SPF) – it is entered into the program as a comment:
Example:
The checksum is then cyclically re–calculated and compared with the reference
checksum. If a deviation is detected, Alarm 27093 "Checksum error NCK–SPL,
%1, %2, %3" is output.
S The system variables $A_INSIP(D), $A_OUTSIP(D), $A_INSEP(D), $A_OUT-
SEP(D) and $A_MARKERSIP(D) are only accessible during the commissioning
phase.
If NCK–SPL execution is interrupted for any reason or the SI system variables are
changed by another program, then this is detected by the cyclic crosswise data
comparison with the PLC.
Table 7-4 Response to SPL errors
Event
Crosswise data comparison
NCK–PLC identifies an error
SPL program file is to be changed
(written, deleted, re–named, edited)
Warning
!
The protective mechanisms that prevent changes to the NCK–SPL file and the
NCK–SPL instructions (statements) are only completely effective if
MD $MN_PREVENT_SYNACT_LOCK[0,1] is set to the value range of the
synchronous action IDs used in the NCK–SPL.
The machine construction OEM must ensure that the protective mechanisms are
activated no later than after the completion of the acceptance test and the values,
set in MD $MN_PREVENT_SYNACT_LOCK[0,1] are documented in the
acceptance report.
After commissioning has been completed, the access rights to the SAFE.SPF file
must be set to the correct access level for writing/reading/deleting access
operations (manufacturer or service).
© Siemens AG 2008 All Rights Reserved
SINUMERIK 840D sl/SINAMICS S120 SINUMERIK Safety Integrated (FBSI sl) – 05.2008 Edition
; SAFE_CHECKSUM = 000476bbH
MD 11500 $MN_PREVENT_
SYNACT_LOCK[m,n] equal to 0
Alarm 27090 is triggered
No response
Connecting Sensors/Actuators
7.3 Safe programmable logic (SPL)
MD 11500 $MN_PREVENT_
SYNACT_LOCK[m,n] not equal to 0
Alarm 27090 is triggered and in addi-
tion, STOP D/E is triggered
Alarm 27093 is triggered
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