Compressor Functions; Nc Block Compression - Siemens SINUMERIK 828D Function Manual

3.5

Compressor functions

3.5.1

NC block compression

Function
COMPON, COMPCURV
The compressor functions COMPON and COMPCURV generate one polynomial block from up to 10 consecutive
linear blocks. The polynomial blocks of the compressor functions have the following properties:
• COMPON: Continuous velocity block transitions.
• COMPCURV: Continuous velocity and acceleration block transitions
COMPCAD
The compressor functions COMPCAD can generate one polynomial block from theoretically as many linear
blocks as required. The polynomial blocks have constant velocity and acceleration at the block transitions.
Corners that are desirable are identified as such and taken into account.
The maximum tolerable deviation of the calculated path to the programmed points can be specified using
machine data for all compressor functions. Different than for COMPON and COMPCURV, for COMPCAD, the
specified tolerances are not utilized in different directions in neighboring paths. In fact, COMPCAD attempts to
achieve - under similar conditions - also similar deviations from the programmed points.
The common objective of compressor functions is to optimize the surface quality and machining speed by
achieving continuous block transitions and increasing the path length for each block.
COMPCAD is very processor and memory-intensive. It is recommended that COMCAD is only used there where
surface improvements were not successful using measures in the CAD/CAM program.
Availability
For SINUMERIK 828D, NC block compression is only available for the milling versions.
Rated conditions
• The compressor functions COMPON, COMPCURV and COMPCAD compress straight blocks of the form:
N... G01 X... Y... Z... F...
The COMPCAD compressor function also compresses all types of circular blocks.
• When orientation transformation (TRAORI) is active, and under certain preconditions, the compressor
functions COMPON, COMPCURV and COMPCAD can also compress motion blocks for tool orientation and
tool rotation.
References:
Function Manual Special Functions; 3 to 5-Axis Transformation (F2),
Chapter: "Compression of the orientation (COMPON, COMPCURV and COMPCAD)"
• The position data in the blocks to be compressed can be realized as required, e.g. X100, X=AC(100),
X=R1*(R2+R3)
• The compression operation is then interrupted by every other command, e.g. auxiliary function output, in and
between the blocks to be compressed.
Basic Functions
Function Manual, 09/2011, 6FC5397-0BP40-2BA0
B1: Continuous­path Mode, Exact Stop, LookAhead
3.5 Compressor functions
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