Siemens SINUMERIK 840C - Manual (Page 956)

09.95 12 Functional Descriptions
12.19 Interpolation and compensation with tables and temperature compensation
12.19 Interpolation and compensation with tables and temperature
compensation
Corresponding data:
• IKA data 1 - 3 IKA configuration, IKA curves, IKA compensation points
• NC MD 356* IKA warning limit
• NC MD 1148* IKA/TC velocity
• DB32 DRK bit 5 IKA/TC velocity exceeded
• DB32 DRK bit 6 IKA warning limit exceeded
• The TEMPERATURE COMPENSATION (TC) or INTERPOLATION AND COMPENSATION
WITH TABLES (IKA or IKA Stage 2) option must be installed.
General notes
As a result of the increasing demands placed on machine tools, there is a need for improved
functionality between the machine and measuring system in order to compensate for the
effects of errors. In addition, this level of functionality allows the traversal of an optional
movement overlaid on the programmed geometry.
All the functions are described below.
12.19.1 Options
The following functions are available
• Temperature compensation (TC)
Scope of functions SW 3
• Interpolation and compensation with tables (IKA)
Scope of functions SW 3
• Interpolation and compensation with tables 2 (IKA stage 2)
Scope of functions SW 4
which are available as separate options.
Compensation of errors with TC and IKA
The control system may fail to sense the actual value correctly as a result, for example, of the
following influences:
• Temperature (thermal expansion)
• Effects of mechanical action between axes (e.g. sag)
• Lead screw errors (production tolerances of spindles)
These influences can be compensated as an internal control function by means of TC or IKA.
For this purpose, the machine or measuring system parameters measured by laser are stored
in the control during start-up so that they are available for inclusion in the compensation
calculation. The calculated compensation values are also taken into account by the position
control loop with the result that the axes approach the machine setpoint position selected by
the user.
A method of compensating lead screw errors is already available (see section "Leadscrew
error compensation"), but is limited in terms of application owing to the fixed grid spacing and
the absolute compensation value.
© Siemens AG 1992 All Rights Reserved 6FC5197- AA50 12–181
SINUMERIK 840C (IA)