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10.18.5
Correction Table for LINAX® / ELAX®
Depending on the
application’s construction in which a
LINAX® or ELAX® linear motor axis is used, it is possible
that the encoder position does not correspond to the
actual physical position of the linear motor slide (e.g. in
cross table or for high cantilevered applications with
leverage effect).
To a certain degree, the XENAX® servo controller offers the
possibility to correlate the encoder position with the actual
position. The correction table in WebMotion® offers 51
entries in which the physical position can be entered in
fixed distances to the encoder position. The physical
position can be measured with an interferometer.
The range for the way can be freely selected.
Furthermore, the starting point and the distances
between the entries of the table can be defined. If for
example the range 0-
100’000 increments shall be
corrected, the starting position is 0inc and the
distance for the 50 remaining table entries is 2’000
inc (100’000 / 50).
The correction values for the table are determined as
follows: If the correction table is deactivated, all
positions that were entered in the table are being
driven to (example above: 0inc, 2‘000inc, 4‘000inc, …
,
100‘000inc). At each position, the actual physical
position has to be measured and entered in the
correction table. When activating the correction
table, all driving commands refer to the actual
physical position and no longer to the encoder
position of the LINAX® or ELAX® linear motor axes.
Limitations
- Correction table is not supported in case of rotary
motors
- Correction table is not supported with
communication over Real time Bus module (for
example EtherCAT)
- This correction table runs with following
commands and functions only: >G, >GP, >GW,
>IX, >PRF, >RR, >RW, >TP
