Siemens SINUMERIK 840D sl Function Manual page 370

Compensations (K3)
Interpolatory compensation
● Compensation with modulo function
370
($AA_ENC_COMP_IS_MODULO[e,AXi])
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[e,k,AXi]) is immediately followed by the
compensation value at position $AA_ENC_COMP_MIN (≙ interpolation point
$AA_ENC_COMP[e,0,AXi]).
For rotary axes with modulo 360° degrees it is therefore suitable to program 0°
($AA_ENC_COMP_MIN) as the initial position and 360° ($AA_ENC_COMP_MAX) as the
end position.
The compensation values entered for these two positions should be the same as
otherwise the compensation value jumps from MAX to MIN at the transition point and vice
versa.
$AA_ENC_COMP_IS_MODULO[e,AXi] = 0: Compensation without modulo function
$AA_ENC_COMP_IS_MODULO[e,AXi] = 1: Compensation with modulo function
CAUTION
When the compensation values are entered it is important that all interpolation points be
assigned a position value within the defined range (i.e. no gaps). Otherwise, the
previous valid position value is used for these interpolation points.
Note
Table parameters containing positional information are automatically converted when the
system of units is changed (when the setting in the following machine data is altered):
MD10240 $MN_SCALING_SYSTEM_IS_METRIC
(basic system metric)). The position information is always interpreted in the current
measuring system. Conversion must be implemented externally.
Automatic conversion of positional information can be configured by the setting in the
following machine data:
MD10260 $MN_CONVERT_SCALING_SYSTEM=1
External conversion is no longer necessary.
References: /FB1/ Function Manual, Basic Functions; Velocities, Setpoint-Actual Value
Systems, Closed-Loop Control (G2)
Function Manual, 03/2009, 6FC5397-1BP10-4BA0
Extended Functions