Examples - Siemens SINUMERIK 840D sl Function Manual

System of units
Table parameters with position data are automatically converted if the system of units changes
(MD10240 $MN_SCALING_SYSTEM_IS_METRIC).
The position information is always interpreted in the current measuring system. Conversion
must be implemented externally.
Automatic conversion
An automatic conversion of the position data is performed for the following settings:
MD10260 $MN_CONVERT_SCALING_SYSTEM = 1
This activates the following axial machine data:
MD32711 $MA_CEC_SCALING_SYSTEM_METRIC (measuring system 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
In order to avoid excessively high velocities and accelerations on the machine axis due to large
compensation values for the sag compensation, the total compensation value is monitored
and is 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

Example 1: Sag compensation
Depending on the position of the axis Y1, an additional compensation value is applied to the
set position of axis Z1.
Compensation table used: Table 1 ⇒ Index = 0
Extended Functions
Function Manual, 10/2015, 6FC5397-1BP40-5BA3
K3: Compensations
5.4 Interpolatory compensation
279