Fixed-Point Approach (G75, G751) - Siemens SINUMERIK 840D sl Programming Manual

Supplementary commands

14.5 Fixed-point approach (G75, G751)

14.5 Fixed-point approach (G75, G751)
Function
The non-modal command G75/G751 can be used to move axes individually and
independently of one another to fixed points in the machine space, e.g. to tool change points,
loading points, pallet change points, etc.
The fixed points are positions in the machine coordinate system which are stored in the
machine data (MD30600 $MA_FIX_POINT_POS[n]). A maximum of four fixed points can be
defined for each axis.
The fixed points can be approached from every NC program irrespective of the current tool or
workpiece positions. An internal preprocessing stop is executed prior to moving the axes.
The approach can be made directly (G75) or via an intermediate point (G751):
Conditions
The following conditions must be satisfied to approach fixed points with G75/G751:
• The fixed-point coordinates must have been calculated exactly and written to machine
data.
• The fixed points must be located within the valid traversing range ( → note the software
limit switch limits!)
• The axes to be traversed must be referenced.
• No tool radius compensation must be active.
• A kinematic transformation may not be active.
• None of the axes to be traversed must be involved in active transformation.
• None of the axes to be traversed must be a following axis in an active coupling.
• None of the axes to be traversed must be an axis in a gantry grouping.
• Compile cycles must not activate motion components.
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Programming Manual, 09/2011, 6FC5398-1BP40-2BA0
Fundamentals