Positional Data; General Notes; Program Dimensions - Siemens SINUMERIK 840DE Programming Manual

Positional Data

3.1

General notes

3.1.1

Program dimensions

In this section you will find descriptions of the commands, with which you can directly
program dimensions taken from a drawing. This has the advantage that no extensive
calculations have to be made for NC programming.
Note
The commands described in this section stand in most cases at the start of a NC program.
The way, in which these functions are combined, is not intended to be a patent remedy. For
example, the choice of working plane may be made at another point in the NC program.
The real purpose of this and all the following sections is to illustrate the conventional
structure of an NC program.
Overview of typical dimensions
The basis of most NC programs is a drawing with concrete dimensions.
When implementing in a NC program, it is helpful to take over exactly the dimensions of a
workpiece drawing into the machining program. These can be:
• Absolute dimension, G90 modally effective applies for all axes in the block, up to
• Absolute dimension, X=AC(value) only this value applies only for the stated axis and is
• Absolute dimension, X=CC(value) directly approaching the position by the shortest route,
• Absolute dimension, X=ACP(value) approaching the position in positive direction, only
Fundamentals
Programming Manual, 10.2004 Edition, 6FC5 298-7AB00-0BP1
revocation by G91 in a following block.
not influenced by G90/G91. This is possible for all axes and also for SPOS, SPOSA
spindle positionings, and interpolation parameters I, J, K.
only this value applies only for the stated rotary axis and is not influenced by G90/G91. Is
also possible for SPOS, SPOSA spindle positionings.
this value is set for the rotary axis, the range of which is set in the machine datum to 0...<
360°.
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