Siemens sinumerik 840D sl Function Manual page 442

Brief description
Tangential control
The tangential control function belongs to the category of NC functions with coupled axes. It
is characterized by the following features:
• There are two leading axes which are moved independently by means of normal
• The leading axes and following axis are only coupled at certain times, i.e. the coupling
• Tangential control is defined for the basic coordinate system/workpiece coordinate
• The leading axes are defined as geometry axes and the following axis as a rotary axis.
• The coupled axes are assigned to the same channel.
• The position of the following axis can be the input value for a transformation.
• Tangential control is only active in AUTOMATIC and MDA modes.
Corners in the path contour
If the contour defined by the leading axes contains a corner the following points must noted
with respect to the following rotary axis. You can select one of two different types of
response:
• The path velocity is reduced to such an extent that the following axis reaches its target
• If TLIFT has been programmed, an intermediate block is inserted at any corner whose
Special functions: Tangential Control (T3)
Function Manual, 11/2006, 6FC5397-2BP10-2BA0
traversing instructions (leading axes). In addition there is a following axis whose position
is determined as a function of the status of these leading axes (position, tangent).
can be switched on and off by program instructions.
system.
position synchronously with the other axes.
angle is greater than the following machine data:
MD37400 $MA_EPS_TLIFT_TANG_STEP (Tangent angle for corner recognition)
In this inserted intermediate block, the rotary axis is moved as fast as possible to the
position corresponding to the tangent after the corner. The limit values set for this axis
are not violated.
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