Reference Point Approach (G74) - Siemens SINUMERIK 840Di sl Programming Manual

Positional Data

3.10 Reference point approach (G74)

3.10 Reference point approach (G74)
Function
When the machine has been powered up (where incremental position measuring systems
are used), all of the axis slides must approach their reference mark. Only then can traversing
movements be programmed.
The reference point can be approached in the NC program with G74.
Programming
G74 X1=0 Y1=0 Z1=0 A1=0 ... Programmed in a separate NC block
Parameter
G74
X1=0 Y1=0 Y1=0...
A1=0 B1=0 C1=0...
Note
A transformation must not be programmed for an axis which is to approach the reference
point with G74.
The transformation is deactivated with command TRAFOOF.
Example
When the measurement system is changed, the reference point is approached and the
workpiece zero point is initialized.
N10 SPOS=0
N20 G74 X1=0 Y1=0 Z1=0 C1=0
N30 G54
N40 L47
N50 M30
114
Reference point approach
The stated machine axis address
X1, Y1, Z1... Reference point approach for linear axes.
A1, B1, C1... Reference point approach for rotary axes.
;Spindle in position control
;Reference point approach for linear axes and
;rotary axes
;Zero offset
;Cutting program
;End of program
Programming Manual, 11/2006, 6FC5398-1BP10-2BA0
Fundamentals