Siemens Sinumerik 840D sl Programming Manual page 915

Feed override
The programmed velocity is overriden by the current velocity setting made via the →
machine control panel or from the → PLC (0 to 200%). The feedrate can also be corrected
by a programmable percentage factor (1-200%) in the machining program.
Finished-part contour
Contour of the finished workpiece. See → Raw part.
Fixed machine point
Point that is uniquely defined by the machine tool, e.g. machine reference point.
Fixed-point approach
Machine tools can approach fixed points such as a tool change point, loading point, pallet
change point, etc. in a defined way. The coordinates of these points are stored in the control.
The control moves the relevant axes in → rapid traverse, whenever possible.
Frame
A frame is an arithmetic rule that transforms one Cartesian coordinate system into another
Cartesian coordinate system. A frame contains the following components: → zero offset, →
rotation, → scaling, → mirroring.
Geometry
Description of a → workpiece in the → workpiece coordinate system.
Geometry axis
Geometry axes are used to describe a 2- or 3-dimensional area in the workpiece coordinate
system.
Ground
Ground is taken as the total of all linked inactive parts of a device which will not become live
with a dangerous contact voltage even in the event of a malfunction.
Helical interpolation
The helical interpolation function is ideal for machining internal and external threads using
form milling cutters and for milling lubrication grooves.
The helix comprises two movements:
• Circular movement in one plane
• A linear movement perpendicular to this plane
Job planning
Programming Manual, 02/2011, 6FC5398-2BP40-1BA0
Glossary
915