Siemens SINUMERIK 840D sl Function Manual page 386

Data Description
8.4 System variables
Bit 0... 27:
Bit 28:
Bit 29:
Bit 30:
Programming example:
; For a crosswise data comparison error, set ext. output
N1060 IDS = 06 WHENEVER $A_STATSID <> 0 DO $A_OUTSE[1] = 1
These system variables can only be read by the user program.
System variable $A_CMDSI[1]
This system variable can be used to increase the time up to 10 s monitoring the
signal changes in the crosswise data comparison between NCK and PLC.
This means that signal differences between the NCK and PLC system variables
can be tolerated for up to 10s without Alarm 27090 being output.
This system variable can be read and written into by the user program.
System variable $A_LEVELSID
This system variable is used to display the stack level of the signal change moni-
toring in the crosswise data comparison between NCK and PLC. This variable indi-
cates the current number of signals to be checked by the crosswise data compari-
son function.
System variables $A_xxxP(D)
Images (mapping) of the PLC–SPL interface and markers are provided to make it
easier to commission the SPL. The system variables are updated in the same
clock cycle as the crosswise data comparison between the NCK and the PLC.
These system variables can only be accessed reading.
These system variables may only be used in the commissioning phase.
As soon as commissioning has been signaled as completed, access to these
system variables is blocked. If these program commands are processed, Alarm
17210 is output to indicate an error condition.
8-386
SINUMERIK 840D sl/SINAMICS S120 SINUMERIK Safety Integrated (FBSI sl) – 05.2008 Edition
Crosswise data comparison error in the input/output signals or
markers.
Crosswise data comparison error "SPL protection status" (status
$MN_PREVENT_SYNACT_LOCK not equal to DB18.DBX36.0).
Time error in the communications between NCK and PLC (in 5 s, all
ext. NCK–SPL outputs are set to zero, the PLC goes to stop).
PLC signals a stop to the NCK.
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05.08