Siemens SINUMERIK 808D Function Manual page 107

The compensation value of interpolation point k is used for all positions larger than the end position (exception: table with
modulo function). Compensation values which are greater than k are inactive.
● Compensation with modulo function: $AA_ENC_COMP_IS_MODULO[0,AXi] = 1
When compensation with modulo function is activated, the compensation table is repeated cyclically; i.e. the
compensation value at position $AA_ENC_COMP_MAX (interpolation point $AA_ENC_COMP[0,k,AXi]) is immediately
followed by the compensation value at position $AA_ENC_COMP_MIN (interpolation point $AA_ENC_COMP[0,0,AXi]).
For rotary axes with modulo 360° it is therefore suitable to program 0° ($AA_ENC_COMP_MIN) as the starting position
and 360° ($AA_ENC_COMP_MAX) as the end position. In this case both compensation values must be entered directly.
Note
When the compensation values are entered, it is important that all interpolation points within the defined range be
assigned a compensation value (i.e. there should be no gaps). Otherwise, the compensation value that was left over
from previous entries at these positions is used for these interpolation points.
Note
Table parameters that contain position data are interpreted through MD10240 SCALING_SYSTEM_IS_METRIC=0 in
inches.
The position data can be automatically re-calculated by performing a manual switchover.
The compensation table can only be loaded when MD32700 ENC_COMP_ENABLE=0 has been set. The value "1"
causes the compensation to be activated and write protection to be applied (output alarm 17070).
Example
The following example shows compensation value inputs for machine axis X1 as a program.
%_N_AX_EEC_INI
CHANDATA(1)
$AA_ENC_COMP[0,0,X1]=0.0
$AA_ENC_COMP[0,1,X1] = 0.01
$AA_ENC_COMP[0,2,X1]=0.012
...
$AA_ENC_COMP[0,120,X1]=0.0
$AA_ENC_COMP_STEP[0,X1]=2.0
$AA_ENC_COMP_MIN[0,X1]=-200.0
$AA_ENC_COMP_MAX[0,X1] = 40.0
$AA_ENC_COMP_IS_MODULO[0,X1]=0
Values for more than 125 interpolation points result in alarm 12400 "Element does not exist".
Compensation table parameters (system variables for LEC):
Function Manual
01/2017
; 1st compensation value (interpolation point 0) +0 mm
; 2nd compensation value (interpolation point 1) +10 mm
; 3rd compensation value (interpolation point 2) +12 mm
; last compensation value (interpolation point 120)
; distance between interpolation points 2.0 mm
; compensation starts at -200.0 mm
; compensation ends at +40.0 mm
; compensation without modulo function M17
107