Siemens sinumerik 840d Programming Manual page 315

08.97
9
840D 840D
NCU 571 NCU 572
NCU 573
Reading table positions, CTAB, CTABINV
With CTAB you can read the following value for a
leading value directly from the part program or from
synchronized actions (Chapter 10).
With CTABINV, you can read the leading value for a
following value. This assignment does not always
have to be unique. CTABINV therefore requires an
approximate value (aproxLW) for the expected
leading value. CTABINV returns the leading value
that is closest to the approximate value. The
approximate value can be the leading value from the
previous interpolation cycle.
Both functions also output the gradient of the table
function at the correct position to the gradient
parameter (degrees). In this way, the you can
calculate the speed of the leading or following axis at
the corresponding position.
Additional notes
Optional specification of the leading or following axis
for CTAB/CTABINV is important if the leading and
following axes are configured in different length
units.
Deleting curve tables, CTABDEL
With CTABDEL you can delete the curve tables.
Curve tables that are active in a coupling cannot be
deleted.
Overwriting curve tables
A curve table is overwritten as soon as is number is
used in another table definition. Active tables cannot
be overwritten.
Additional notes
No warning is output when you overwrite curve tables!
 Siemens AG 2000. All rights reserved
SINUMERIK 840D/840Di/810D/FM-NC Programming Guide Advanced (PGA) – 04.00 Edition
9.3 Curve tables, CTABDEF, CTABEND, CTAB, CTABINV
810D 840Di
Path Traversing Behavior
Following value
degrees
FW
FW
LW
Leading
value
9
Following value
degrees
LW
Leading
value
approx.
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