Siemens SINUMERIK 840C - Manual (Page 981)

12 Functional Descriptions 09.95
12.19.5 Interpolation and compensation with tables
12.19.5.7 Meaning of the data types
• %IKA1, IKA configuration
Every data type can be read or written by defining the relevant type no. The control byte
can be accessed byte by byte or bit by bit.
In the part program. @30C/@40C are used to read and write the data. In the data file they
area addressed via T parameters.
Control byte Data type: 0 Format: 8 bit
The control byte shows the status of the IKA configuration and defines the various function
types.
Meaning of the individual bits:
IKA active Data type: 11 Format: 1 bit
Bit 0=0: Deactivate IKA configuration or IKA relation inactive
Bit 0=1: Activate IKA configuration or IKA relation active
The bit is automatically set or reset with G functions G410/G412 or G402/G403/G400.
IKA direction dependent Data type: 12 Format: 1 bit
Bit 1=0: The effect of IKA configuration is not direction dependent
Bit 1=1: The effect of IKA configuration is direction dependent
IKA negative direction Data type: 13 Format: 1 bit
Bit 2=0: IKA configuration takes effect with a positive direction of input quantity A
Bit 2=1: IKA configuration takes effect with a negative direction of input quantity A
Bit 3: IKA with compensated actual value (up to SW 3)
Data type: 14 Format: 1 bit
Bit 3=0: IKA configuration uses the uncompensated actual value
Bit 3=1: IKA configuration uses the compensated actual value
Correct input value (SW 3 only)
The following effect of the IKA value must be considered. It is explained here using the
example of an axis:
A compensation/additional value (IKA value) calculated by a control curve, here a positive
one, causes the axis to traverse in the negative direction if the axis of the input quantity is
also the axis of the output quantity (e.g. application as leadscrew error compensation
substitute).
Depending on the magnitude of the compensation/additional value, this results in a new
machine position and therefore in a new input quantity. The axis is now in a position for
which another compensation/additional value would be measured/calculated in the curve
measurement/calculation. The difference between this compensation/additional value and
that last calculated depends on the magnitude of the last value and the gradient of the
control curve between these points.
To be able to calculate the new IKA value, it is now necessary to recalculate the last
compensation/additional value for the actual position as the input of the control curve, i.e.
the actual value is approximately compensated. The effective compensation/additional
value is then set iteratively.
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SINUMERIK 840C (IA)