Siemens SINUMERIK 828D Function Manual page 202

B1: Continuous­path Mode, Exact Stop, LookAhead
3.5 Compressor functions
Boundary conditions
• NC-blocks can be combined only if no other details have been programmed except the axial motions and the
feed rate. If, for example, auxiliary functions are programmed, which must be given to the PLC, then this block
cannot be omitted, since it must be active in the interpolator. This is analogous to the possible compression of
G1 blocks with the compressors COMPON, COMPCURV and COMPCAD.
• The maximum number of blocks, which can be combined into a program part one after the other, depends on
the size of the available memory for blocks in the block processing.
This memory is established by the machine data:
MD28070 $MC_MM_NUM_BLOCKS_IN_PREP (number of blocks for block preparation)
Example
In order to attain a higher path velocity when processing the following program, the"combine short spline blocks"
function is activated for BSPLINE interpolation via MD20488:
MD20488 $MC_SPLINE_MODE, bit 0 = 1
Program code
N10 G1 G64 X0 Y0 Z0 F10000
N20 G91 BSPLINE
N30 X0.001 Y0.001 Z0.001
N40 X0.001 Y0.001 Z0.001
N50 X0.001 Y0.001 Z0.001
N60 X0.001 Y0.001 Z0.001
N70 X0.001 Y0.001 Z0.001
N80 X0.001 Y0.001 Z0.001
...
N1000 M30
202
Comment
; BSPLINE-interpolation with a combination of
short spline blocks is effective from here.
Function Manual, 09/2011, 6FC5397-0BP40-2BA0
Basic Functions