Siemens Sinumerik 840D sl Function Manual page 648

Diagnostics
10.2 NCK safety alarms for Sinumerik 840D sl
10-648
SINUMERIK 840D sl/SINAMICS S120 SINUMERIK Safety Integrated (FBSI sl) - - 10.2015 Edition
42
The setting in MD36960 $MA_SAFE_STANDSTILL_VELO_TOL does
not correspond with the associated drive parameter assignment.
Remedy
Copy SI data.
43
Stop response, memory test.
44 - - 57
Explanation
Fault codes 44--57 cannot be clearly assigned to a fault cause. For the
monitoring functions that run internally (e.g. SG), monitoring limits are
internally generated that are referred to a monitoring clock cycle.
Example:
SG1 = 2000 mm/min, monitoring clock cycle = 12 ms
If SG1 is active, then a check is made in every monitoring clock cycle
(MCC) as to whether SG1 was exceeded.
This means that in MCC[n], based on the actual value, a positive and
negative actual value limit is defined that may not be exceeded in
MCC[n+1] in order to still comply with SG1.
SG1 = 2000 mm/min = 33.33 mm/s = 0.4 mm/MCC (for each 12 ms)
If the axis moves more than 0.4 mm in a monitoring clock cycle, then
SG1 would be violated.
The limit values, specified above, in MCC[n+1] are then
Positive: Position actual value (MCC[n]) + 0.4 mm
negative: position actual value (MCC[n]) --0.4 mm
The resulting monitoring limits (positive and negative) that are, in turn
determined independently for both monitoring channels (NCK and
drive) are also compared just like the safe actual positions (refer to fault
code 3). The comparison is for a difference < MD36942
$MA_SAFE_POS_TOL.
If the difference is greater than MD36942 $MA_SAFE_POS_TOL, then
the appropriate fault code is output.
The limit values are then re--generated and compared in every monitor-
ing cycle independently of whether the associated monitoring function
is active or not.
This means that there are three possible causes for this fault code
group.
Causes and remedy
Possible cause 1 (only when commissioning or changing the MD)
The tolerance value for the monitoring function is set differently for the
NCK and drive. This situation actually only occurs when commissioning
the system or making changes and is generally already covered by the
previous fault codes.
Remedy: Set the relevant machine data the same.
Possible cause 2 (in operation)
The limit values are determined based on the actual value. This means
that when the safe actual values of the NCK and drive differ then the
limit values are also different by the defined clearance --> i.e. the fault
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