Examples - Siemens SINUMERIK 840D sl Function Manual

K3: Compensation
5.4 Interpolatory compensation
With this setting, the following axial machine data are activated:
MD32711 $MA_CEC_SCALING_SYSTEM_METRIC (system of units for sag compensation)
The measuring system for all tables effective for this axis is set in this machine data. Hereby
all position entries are interpreted together with the calculated total compensation value in
the configured measuring system. External conversions of position information are no longer
necessary with a measuring system change.
Monitoring
To avoid excessive velocities and acceleration rates on the machine axis as a result of
applying sag compensation, the total compensation value is monitored and limited to a
maximum value.
The maximum possible total compensation value for sag compensation is defined on an
axis-for-axis basis using the machine data:
MD32720 $MA_CEC_MAX_SUM (maximum compensation value for sag compensation)
If the determined total compensation value is greater than the maximum value, then a
corresponding alarm is output. Program processing is not interrupted. The compensation
value output as an additional setpoint is limited to the maximum value.
Further, changing the total compensation value is also axially limited:
MD32730 $MA_CEC_MAX_VELO (velocity change for sag compensation)
The specified value acts as a factor and is referred to the maximum axis velocity (MD32000
$MA_MAX_AX_VELO).
An appropriate alarm is signaled when the limit value is exceeded. Program processing is
not interrupted. The path not covered because of the limitation is made up as soon as the
compensation value is no longer subject to limitation.
5.4.3.3

Examples

Compensation table for sag compensation of the Y1 axis
The following example shows the compensation table for sag compensation of axis Y1.
Depending on the position of the Y1 axis, a compensation value is applied to the Z1 axis.
The 1st compensation table (<t> = 0) is used for this.
Program code
%_N_NC_CEC_INI
CHANDATA(1)
$AN_CEC[0,0]=0
$AN_CEC[0,1]=0.01
$AN_CEC[0,2]=0.012
...
372
Comment
; 1st compensation value (interpolation point 0)
; for Z1: ±0µm
; 2nd compensation value (interpolation point 1)
; for Z1: +10µm
; 3rd compensation value (interpolation point 2)
; for Z1: +12µm
Function Manual, 09/2009, 6FC5397-1BP20-0BA0
Extended Functions