Activation - Siemens SINUMERIK 840C Installation Instructions Manual

12 Functional Descriptions
12.19.1 Options
Implementation of any geometry or velocity profiles SW 4 and higher with IKA Stage 2
IKA Stage 2 makes it possible to define a fully optional geometry between an input variable
and the associated output variable. For this purpose, the relevant values of the output quantity
are allocated to a number of interpolation points of the input quantity and stored as a table in
the NC. During part program processing, the values from the output quantity table assigned to
the current values of the input quantity are overlaid. Interpolation between two intermediate
points can be linear or cubic.
Input and output quantities can also be preset to influence velocities and R parameters.
12.19.2

Activation

The following options can be activated at the same time:
• Temperature compensation (TK) for compensation of thermal expansion
• Interpolation and compensation with tables (IKA), e.g. for compensation of lead screw
errors, sag compensation for telescopic axes
Both options are completely independent of one another. The individual results are added on
an axis-specific basis and produce the absolute traversing path of an axis. If several
interpolations or compensations are to be calculated, then all of them have only one common
value as the input quantity. Within an IPO cycle, therefore, a TC value which may have been
calculated beforehand (within the same IPO cycle) is not taken into account in the IKA value
calculation.
The functions are active in all modes after the reference point approach of the axes involved. If
a referenced axis is re-referenced, then the functions are deactivated after cam approach until
the reference point approach process is complete.
The traversing path resulting from the functions involved is shown in the service display in
position control resolutions.
The resulting traversing path or compensation value (sum of TC and all IKA configurations) is
included as an absolute position error in the actual value path calculation. This value must not
be changed by more than a specific amount within each IPO cycle. This limit is distributed
among several IPO cycles by means of a ramping function.
Machine data "IKA warning limit" and "IKA/TC speed" as well as the interface signals "IKA/TC
speed exceeded" and "IKA warning limit exceeded" only apply to the machine error
compensation area.
Example:
MD 300* = 500 mm/min, IPO cycle = 6ms
max. change in output quantity per IPO cycle = 50 µm.
The output quantity is traversed with the velocity set in NC MD 1148*.
The traversing path resulting from TC and IKA is not displayed as an
actual value change in the axis positions.
12–182
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SINUMERIK 840C (IA)