Siemens SINUMERIK 840D sl Function Manual page 467

05.08
© Siemens AG 2008 All Rights Reserved
SINUMERIK 840D sl/SINAMICS S120 SINUMERIK Safety Integrated (FBSI sl) – 05.2008 Edition
10.2 NCK safety alarms for SINUMERIK 840D sl
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 < MD 36942
$MA_SAFE_POS_TOL.
If the difference is greater than MD 36942 $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
code corresponds to the fault image of fault code 3. This can be deter-
mined by checking the safe actual positions.
Remedy: Refer to fault code 3.
Possible cause 3 (in operation)
The associated monitoring function is already active in a monitoring
channel – while in the other monitoring channel another monitoring
function is still active. This is the case if the safe actual positions of the
NCK and drive do not differ but instead there is an entry in drive param-
eters r9710/r9711 (and the 1 appears in parameter r9725) –> i.e. the
fault code corresponds to the fault profile of fault code 1. This can also
be identified using the fault message if for %3 = supplementary info
comparison value NCK or %4 = supplementary info comparison value
drive no real limit value is output but only the value of the calculated
tolerance (refer to the example above (SG1 = 2000 mm/min = 0.4 mm/
monitoring clock cycle), a value of 400 would be displayed as 4%).
Remedy: Refer to fault code 1.
Diagnostics
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