Siemens SINUMERIK 840D sl Function Manual page 258

Connecting sensors and actuators
8.5 Safe programmable logic
Figure 8-32
Crosswise data comparison
Data is cyclically exchanged between the PLC and NCK to check the correct functioning of
the two SPLs (PLC and NCK). Just the same as the comparison between the NCK and the
drive, it cross-checks the signals that the SPL receives, 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 permanently 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 8-2 Signals for crosswise data comparison
NCK-SPL data
$A_INSE[1 ... 64]
$A_OUTSE[1 ... 64]
$A_INSI[1 ... 64]
$A_OUTSI[1 ... 64]
$A_MARKERSI[1 ... 64]
$A_FSDP_ERR_REAC[1...16]
258
Integrating the SPL into the complete system
Signal image of the PLC data
$A_INSEP[1...64]
$A_OUTSEP[1...64]
$A_INSIP[1...64]
$A_OUTSIP[1...64]
$A_MARKERSIP[1...64]
--
PLC-SPL data (DB18)
DBX38.0 ... DBX45.7
DBX46.0 ... DBX53.7
DBX54.0 ... DBX61.7
DBX62.0 ... DBX69.7
DBX70.0 ... DBX77.7
DBW190, DBW200, DBW210
DBW448, DBW458, DBW468
-
DBW548, DBW558, DBW568
Function Manual, 12/2017, 6FC5397-4BP40-6BA1
Safety Integrated