14.COMPENSATION FUNCTION PROGRAMMING B-63324EN/03
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- Fixture offset command
When command G54.2 Pn is specified, a fixture offset is calculated
from the rotary axis angular displacement and the data of n. The fixture
offset becomes valid.
If n is set to 0, the fixture offset becomes invalid.
- When a move command is specified for a rotation axis in G54.2 mode
When a move command is specified for a rotation axis related to fixture
offset in G54.2 mode, vector calculation is performed using the
coordinates of the rotation axis at the end point of the block, and
movement is made to the specified position pointed to by the vector on
the workpiece coordinate system.
- Operation at reset
The KWZ bit (bit 6 of parameter 2409) determines whether the fixture
offset is canceled at reset.
When the bit is set to 1, the vector before the reset is retained.
When the bit is set to 0, the vector is cleared.
When the vector is cleared, the machine does not move according to the
vector cleared upon a reset.
- Data setting
(1) Setting a group of three parameters which specify one rotation
axis and two linear axes constituting the plane of rotation
(Parameter No.6068 to 6076)
In each group, specify the number of the rotation axis as the first
parameter and the numbers of the linear axes as the second and
third parameters. The rotation in the normal direction about the
rotation axis must agree with the rotation from the positive side of
the linear axis set as the second parameter to the positive side of
the linear axis set as the third parameter.
Example) Suppose that a machine has four axes, X, Y, Z, and C.
The X-, Y-, and Z-axes form a right-handed coordinate
system. The C-axis is a rotation axis. When viewed
from the positive side of the Z-axis, a rotation in the
normal direction about the C-axis is treated as the
counterclockwise rotation around the Z-axis.
For this machine, specify the parameters as follows :
First parameter : 4 (C-axis)
Second parameter : 1 (X-axis)
Third parameter : 2 (Y-axis)
Up to three groups of parameters can be set. In calculation of the
fixture offset, the data of the rotation axis specified in the first
group is calculated first. Then, the data of the second and third
groups are calculated.
If a machine has two or more rotation axes and the plane of
rotation depends on the rotation about another rotation axis, the
plane of rotation is set when the angular displacement about the
rotation axis is 0 .