Siemens SINUMERIK 840D sl Function Manual page 131

The following elements can be protected:
● Permanent parts of the machine and attachments (e.g. toolholding magazine, swiveling
probe). Only the elements that can be reached by possible axis constellations are relevant.
● Moving parts belonging to the tool (e.g. tool, toolholder)
● Moving parts belonging to the workpiece (e.g. parts of the workpiece, clamping table,
clamping shoe, spindle chuck, tailstock).
Protection zones are defined via part program instructions or system variables so that they
completely surround the element to be protected. The activation and deactivation of protection
zones also takes place via part program instructions.
Protection-zone monitoring by the NC is channelspecific, i.e. all the active protection zones of
a channel monitor one another for collisions.
Definition of a protection zone
It is possible to define 2dimensional or 3dimensional protection zones as polygons with a
maximum of ten corner points. The protection zones can also contain arc contour elements.
Polygons are defined in a previously defined plane.
Expansion in the 3rd dimension can be limited between - ∞ to + ∞.
The following four cases are possible:
● Dimension of the protection zone from -∞ to +∞
● Dimension of the protection zone from -∞ to the upper limit
● Dimension of the protection zone from the lower limit to +∞
● Dimension of protection zone from lower limit to upper limit.
Coordinate system
The definition of a protection zone takes place with reference to the geometric axis of a channel
in the basic coordinate system.
Reference
● Tool-related protection zones
Coordinates for toolrelated protection zones must be given as absolute values referred to
the tool carrier reference point F.
● Workpiece-related protection zones
Coordinates for workpiecerelated protection zones must be given as absolute values
referred to the zero point of the basic coordinate system.
Note
If no toolrelated protection zone is active, the tool path is checked against the workpiece-
related protection zones.
If no workpiece-oriented protection zone is active, protection-zone monitoring does not take
place.
Basic Functions
Function Manual, 01/2015, 6FC5397-0BP40-5BA2
A3: Axis Monitoring, Protection Zones
3.3 Protection zones
131