T3: Tangential Control - 840D Sl Only; Brief Description - Siemens SINUMERIK 840D sl Function Manual

T3: Tangential control - 840D sl only

11.1

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 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).
● The leading axes and following axis are only coupled at certain times, i.e. the coupling can
be switched on and off by program instructions.
● Tangential control is defined for the basic coordinate system/workpiece coordinate system.
● 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
position synchronously with the other axes.
● If TLIFT has been programmed, an intermediate block is inserted at any corner whose
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.
Canceling of follow-up grouping
The definition of a follow-up grouping can be canceled in order to track new leading axes with
the following axis.
Special functions
Function Manual, 01/2015, 6FC5397-2BP40-5BA2
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