Siemens SINUMERIK 840D sl Function Manual page 202

Detailed description
2.5 NC block compressor COMPON, COMPCURV, -CAD
2.5 NC block compressor COMPON, COMPCURV, -CAD
COMPON, COMPCURV
The modal G code COMPON or COMPCURV can be used to activate an "NC block
compressor".
This function collects a series of linear blocks during linear interpolation (the number is
limited to 10) and approximates them within a tolerance specified in machine data via a 3rd
order (COMPON) or 5th order (COMPCURV) polynomial.
One traversing block is processed by the NC instead of a large number of small blocks.
COMPCAD
The COMPCAD G code can be used to select a further compression, which optimizes the
surface quality and velocity. The interpolation accuracy can again be specified in machine
data.
COMPCAD is processor and memoryintensive. It should only be used if surface quality
enhancement measures cannot be incorporated in the CAD/CAM program.
The programming is described in:
References:
/PGA/ Programming Manual Work Preparation
The compressor for orientation transformation is described in:
References:
/FB3/Function Manual, Special Functions; 3- to 5Axis Transformation (F2)
The following three machine data are available for the compressor function:
MD20170
$MC_COMPRESS_BLOCK_PATH_LIMIT
MD33100 $MA_COMPRESS_POS_TOL
MD20172 $MC_COMPRESS_VELO_TOL
50
This MD specifies the maximum path length for
block compression. Longer blocks are not
compressed.
A tolerance can be specified for each axis.
This value specifies the maximum deviation of
the generated spline curve from the
programmed end points.
The higher the values, the more blocks can be
compressed.
The maximum permissible deviation of the path
feedrate while the compressor is active in
conjunction with FLIN and FCUB can be
specified here (does not apply to the COMPCAD
command).
Basic logic functions: Continuouspath Mode, Exact Stop, LookAhead (B1)
Function Manual, 11/2006, 6FC5397-0BP10-2BA0