Siemens SINUMERIK 840D sl Function Manual page 203

Recommendation for MD settings
The following machine data affect the compressor function and should contain the following
values (specified in mm):
Machine data
MD18360 $MN_MM_EXT_PROG_BUFFER_SIZE (FIFO buffer
size for processing from external)
MD28520 $MC_MM_MAX_AXISPOLY_PER_BLOCK
(maximum number of axis polynomials per block)
MD28530 $MC_MM_PATH_VELO_SEGMENTS (Number of
memory elements for limiting the path velocity)
MD28540 $MC_MM_ARCLENGTH_SEGMENTS (number of
memory elements for displaying the arc length function)
MD28070 $MC_MM_NUM_BLOCKS_IN_PREP (number of
blocks for block preparation)
MD28060 $MC_MM_IPO_BUFFER_SIZE (number of NC
blocks for block preparation)
SD42470 $SC_CRIT_SPLINE_ANGLE (spline limit angle for
compressor)
MD20170 $MC_COMPRESS_BLOCK_PATH_LIMIT (max.
path length of an NC block with compression)
MD20172 $MC_COMPRESS_VELO_TOL (max. allowed
tolerance of the path feedrate with compression)
MD32310 $MA_MAX_ACCEL_OVL_FACTOR[AX1] (overload
factor for axial jumps in velocity)
MD32310 $MA_MAX_ACCEL_OVL_FACTOR[AX2]
MD32310 $MA_MAX_ACCEL_OVL_FACTOR[AX3]
MD20490 $MC_IGNORE_OVL_FACTOR_FOR_ADIS
(G641/G642 irrespective of the overload factor).
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.
Experience has shown that a value of 0.01 is suitable for most applications:
MD33100 $MA_COMPRESS_POS_TOL[AX1] = 0.01 (maximum tolerance with compression).
MD33100 $MA_COMPRESS_POS_TOL[AX2] = 0.01
MD33100 $MA_COMPRESS_POS_TOL[AX3] = 0.01
If not, the value can be increased to 0.02, for example:
MD33100 $MA_COMPRESS_POS_TOL[AX1] = 0.02
MD33100 $MA_COMPRESS_POS_TOL[AX2] = 0.02
MD33100 $MA_COMPRESS_POS_TOL[AX3] = 0.02
NewConfig
Basic logic functions: Continuouspath Mode, Exact Stop, LookAhead (B1)
Function Manual, 11/2006, 6FC5397-0BP10-2BA0
2.5 NC block compressor COMPON, COMPCURV, -CAD
Detailed description
Recommended value
100
3
5
10
60
100
36
20
100
<Value for G64 operation>
Value for G64 operation
<Value for G64 operation>
1
51