Siemens Sinumerik 840D sl Programming Manual page 195

Exact stop
If exact stop is programmed, the position specified in the block is approached accurately and
- if necessary - very slowly. To reduce the startup speeds, -> exact stop limits are defined for
rapid traverse and feedrate.
Exact stop limit
After all the path axes reach their exact stop limits, the control system reacts as if they have
reached the end point exactly. The -> part program continues with the machining from the
next block.
External work offset
Work offset specified by the -> PLC.
Fast retraction from contour
When an interrupt occurs, a motion can be initiated via the CNC machining program,
enabling the tool to be quickly retracted from the workpiece contour that is currently being
machined. The retraction angle and the retraction path can also be parameterized. An
interrupt routine can be carried out after a rapid retraction.
Feedrate override
In feedrate override, the current feedrate entered in the operator panel or specified by the
PLC is overlaid on the programmed feedrate (0 - 200 %). A feedrate override is also possible
by means of a programmable percentage value (1 - 200 %) in the machining program.
A feedrate correction can also be applied by synchronous actions regardless of the program
currently running.
Fixed machine point
Point that is defined uniquely by the machine tool, e.g. the reference point
Fixed-point approach
The machine tool can be used to approach defined fixed points such as e.g. tool change
points, loading points, palette change points etc. The coordinates of these points are stored
in the control system. If possible, the control system approaches these axes at -> rapid
traverse.
Frame
A frame is an arithmetic rule, with which one Cartesian coordinate system is converted to
another Cartesian coordinate system. A frame consists of the components -> work offset ->
rotation -> scaling and -> mirroring.
ISO Milling
Programming Manual, 06/09, 6FC5398-7BP10-1BA0
Glossary
195