Siemens SINUMERIK 840D sl Function Manual page 509

System variable
$A_STATSID Crosswise data comparison error
triggered if the value is not equal to
0
$A_CMDSI Control word for crosswise data
comparison between the NCK and
PLC (SPL-CDC)
$A_LEVELSID CDC stack level display: Number of
signals for which NCK and PLC de‐
tect different signal levels
Safety Integrated
Function Manual, 12/2017, 6FC5397-4BP40-6BA1
Meaning
Bit 0...5=1: CDC
error in I/O sig‐
nals, markers or
dynamic data of
the FSENDDP/
FRECVDP com‐
munication
Bit 26=1: PROFI‐
safe communica‐
tion error occur‐
red.
Bit 27=1: CDC er‐
ror in static data
Bit 28=1: Cross‐
wise data com‐
parison error
"SPL protection
status" (status
$MN_PRE‐
VENT_SYN‐
ACT_LOCK not
equal to DB18
DBX36.0 /SPL
READY))
Bit 29=1: Time er‐
ror in the commu‐
nications be‐
tween NCK and
PLC (in 5 s, all
ext. NCK-SPL
outputs are set to
0, then the PLC
goes to stop)
n = 1: Increase
the time for the
signal change
monitoring to 10
s
[0, MAX_INT]
Value range Data type
INT
BOOL
INT
Data descriptions
9.7 System variable
Possible access for
Part Synchronized
program action
r w r w
x x
x x x x
x x
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