Siemens SINUMERIK 840D sl Programming Manual page 259

3.3 Checking for protection zone violation, working area limitation and software limits (CALCPOSI)
As in the normal traversing operation, the monitoring of the software limits and the operating
range limits depends on the active settings (interface signals for selecting the software limits
1 or software limits 2, GWALIMON/WALIMOF, setting data for the specific activation of the
operating range limits and for the specification whether or not the radius of the active tool is
to be considered for the monitoring of the operating range limits).
For certain kinematic transformations (e.g. TRANSMIT), the position of the machine axes
cannot be determined uniquely from the positions in the workpiece coordinate system (WCS)
(non-uniqueness). In the normal traversing operation, the uniqueness normally results from
the previous history and the condition that a continuous movement in the WCS must
correspond to a continuous movement in the machine axes. When monitoring the software
limits using the CALCPOSI function, the current machine position is therefore used to
resolve non-unique determinability in such cases. If necessary, a STOPRE must be
programmed in front of CALCPOSI to input valid machine axis positions to the function.
It is not guaranteed that the separation to the protection zones specified in _DLIMIT[3] can
always be maintained for a movement on the specified traversal path. Therefore if the end
point returned in _MOVDIST is lengthened by this distance, no protection zone is violated,
even though the straight line may pass extremely close to a protection zone.
Note
You will find details on working area limitations in the
/PG/ Fundamentals Programming Manual,
on the software limits in
/FB1/ Function Manual, Basic Functions; Axis Monitoring, Protection Zones (A3).
Job Planning
Programming Manual, 06/2009, 6FC5398-2BP20-0BA0
Protection zones
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