Siemens SINUMERIK 840D sl Function Manual page 224

Connecting Sensors/Actuators
7.3 Safe programmable logic (SPL)
Crosswise data comparison
Data is cyclically exchanged between the PLC and NCK to check the correct func-
tioning of the two SPLs (PLC and NCK). Just the same as the comparison be-
tween the NCK and the drive, it cross–checks the signals that arrive at the SPL,
the safety–related signals generated by the SPL as well as internal markers.
The discrepancy time for the crosswise data comparison of SPL variables is per-
manently set to 1 s (or 10 s $A_CMDSI).
The following signals are included in the crosswise data comparison between the
NCK and the PLC:
Table 7-3 Signals for crosswise data comparison
External SPL inputs
External SPL outputs
Internal SPL inputs
Internal SPL outputs
SPL markers
"SPL commissioning phase
completed"
"Stop for SPL–crosswise data
comparison error"
If an error is detected on one of the monitored signals, this is indicated using Alarm
27090 and the configured stop response (STOP D/E) is initiated.
If a difference is detected, Alarm 27090 "Error for crosswise data comparison
NCK–PLC" is output. In addition, a STOP D/E is initiated if the SPL commissioning
phase is defined as having been completed.
The criterion "commissioning phase completed" is derived from the NCK–MD
$MN_PREVENT_SYNACT_LOCK[0,1] in the NCK. If one of the two field entries is
not equal to 0, "commissioning phase completed" is set internally by the crosswise
data comparison. On the PLC side, this requirement is entered using
DB18.DBX36.0. If this bit is set to "1", then the commissioning phase is considered
to have been completed. An SPL crosswise data comparison error only results in a
stop response after the SPL commissioning phase has been completed.
The stop response for an SPL crosswise data comparison error is set in the NCK
using NCK–MD $MN_SPL_STOP_MODE. If the MD value is 3, for an SPL cross-
wise data comparison error, a STOP D is initiated – for an MD value of 4, a STOP
E is initiated. On the PLC side, this stop response is entered using DB18.DBX36.1.
If this bit is set to "1", for an SPL crosswise data comparison error, a STOP E is
initiated – otherwise a STOP D.
Any changes to data on the NCK and PLC side do not take effect until after power on.
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SINUMERIK 840D sl/SINAMICS S120 SINUMERIK Safety Integrated (FBSI sl) – 05.2008 Edition
NCK
$A_INSE[1 ... 64]
$A_OUTSE[1 ... 64]
$A_INSI[1 ... 64]
$A_OUTSI[1 ... 64]
$A_MARKERSI[1 ... 64]
$MN_PREVENT_SYN-
ACT_LOCK[0,1]
$MN_SPL_STOP_MODE
PLC
SPL_DATA.INSEP[1...64]
SPL_DATA.OUTSEP[1...64]
SPL_DATA.INSIP[1...64]
SPL_DATA.OUTSIP[1...64]
SPL_DATA.MARKER-
SIP[1...64]
DB18.DBX36.0
DB18.DBX36.1
© Siemens AG 2008 All Rights Reserved
05.08