Commissioning - Siemens SINUMERIK 840D sl Function Manual

K3: Compensations
5.4 Interpolatory compensation
Complex compensations
Since it is possible to use the position of an axis as the input quantity (base axis) for several
tables, to derive the total compensation value of an axis from several compensation
relationships (tables) and to multiply tables, it is also possible to implement sophisticated and
complex beam sag and angularity error compensation systems.
This function also makes it possible to deal with different error sources efficiently. For example,
it is possible to combine a table with a modulo function for a periodic recurring error component
with a second table without a modulo function for an aperiodic error component for the same
axis.
Leadscrew errors can also be compensated with this function by parameterizing an identical
axis for the base and compensation axes. However, in contrast to the MSEC, measuring-
system switchovers are not automatically registered in this case.
Preconditions / activation
The "sag compensation" function does not become active until the following conditions are
fulfilled:
● Compensation is activated for the participating machine axes (compensation axis):
MD32710 $MA_CEC_ENABLE[<AXi>] = 1
● The compensation values are stored in the static user memory and are active (POWER
ON).
● The evaluation of the compensation table used is enabled:
SD41300 $SN_CEC_TABLE _ENABLE[<t>] = 1
● The current measuring system of the base and compensation axes is referenced:
DB31, ... DBX60.4 or 60.5 == 1 (referenced/synchronized 1 or 2)
If the reference is lost during the following operation, e.g. because the encoder limit
frequency has been exceeded (DB31, ... DBX60.4 or 60.5 == 0), compensation is disabled.
5.4.3.2

Commissioning

The first commissioning step is to define the compensation table. This is done by setting the
number of interpolation points required for each axis. On the next power-on, the compensation
tables will be generated and filled with default values. The next commissioning step is to
parameterize the compensation data by means of system variables. This can be done in two
ways:
● Start an NC program in which the system variables will be written.
● Transfer the compensation tables from an external computer to the control.
Note
To load the compensation tables, all compensation functions for all axes must be
deactivated:
● MD32700 $MA_ENC_COMP_ENABLE[<axis>] == 0
● MD32710 $MA_CEC_ENABLE[<axis>] == 0
276
Function Manual, 10/2015, 6FC5397-1BP40-5BA3
Extended Functions