Siemens Sinumerik 840D sl Programming Manual page 204

Glossary
PLC programming
The PLC is programmed using the STEP 7 software. The STEP 7 programming software is
based on the WINDOWS standard operating system and contains the functionality of STEP
5 programming with innovative enhancements and developments.
Polar coordinates
A coordinate system, in which the position of a point in the plane is defined with a defined
axis from the perspective of its distance from the coordinate origin and the angle formed by
the radius vector.
Polynomial interpolation
Polynomial interpolation is a means with which a very large range of curve characteristics
including straight line, parabola and exponential functions (SINUMERIK 840D/810D) can be
created.
Positioning axis
An axis that executes auxiliary movement in the machine (e.g., tool magazine, palette
transport). Positioning axes are axes that do not interpolate with -> path axes.
Preprocessing memory, dynamic
The traversing blocks are prepared before their execution (pre-processed) and stored in a
"preprocessing" memory. Block sequences can be executed from this memory at a very high
speed. Blocks can be loaded in the preprocessing memory continuously during the
machining.
Preprocessing stop
Program command The next block in a part program is executed only if all the earlier
prepared blocks stored in the preprocessing memory have been processed.
Preset
The machine zero point can be redefined in the machine coordinate system by means of the
preset function. No axis is traveled during preset; instead, a new position value is input for
the current axis position.
Programmable frames
New starting points of a coordinate system can be defined dynamically with programmable -
> frames when the program is running. One differentiates between absolute definitions in
which new frames are used, and additive definitions in which the definition is undertaken with
reference to an existing starting point.
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Programming Manual, 06/09, 6FC5398-7BP10-1BA0
ISO Milling