Alarm Behavior - Siemens SINUMERIK 840D sl Function Manual

W1: Tool offset
2.5 2D tool radius compensation
Maintain stability of closed contour
If a radius of two circles is increased slightly, a third block may be necessary in order to maintain
the stability of the closed contour. This is the case if two adjacent blocks, which represent two
possible intersection points for a closed contour, are skipped due to the compensation.
A stable closed contour can be achieved by choosing the first intersection point instead of the
second.
SD42496 $SC_CUTCOM_CLSD_CONT ≠ 0 (response of TRC for closed contour).
In that case, the second intersection point is always reached, even if the block is skipped. A
third block is then not required.
2.5.11

Alarm behavior

Alarm during preprocessing
If a tool radius compensation alarm is output during preprocessing, main-run machining stops
at the next block end reached, i.e. usually at the end of the block currently being interpolated
(if Look Ahead is active, once the axes have come to a stop).
Alarms for preprocessing stop and active tool radius compensation
Tool radius compensation generally requires at least one of the following traversing blocks
(even more for bottlenecks) to determine the end point of a block. Since the preprocessing stop
of such a block is not available, traversing continues to the offset point in the last block.
Correspondingly, the offset point in the start point is approached in the first block after a
preprocessing stop.
The contour obtained may deviate considerably from the one that would result without
preprocessing stop. Contour violations in particular are possible. Therefore the following
setting data was introduced:
SD42480 $MC_STOP_CUTCOM_STOPRE (alarm response for TRC and preprocessing
stop).
The response of the tool radius compensation remains unchanged compared to the previous
status, and/or an alarm is output for preprocessing stop during active tool radius compensation
and the program is halted, depending on the value.
The user can acknowledge this alarm and continue the NC program with NC start or abort it with
RESET.
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Function Manual, 06/2019, A5E47435126B AA
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