Zero Points And Reference Points - Siemens SINUMERIK 840D sl Programming Manual

1.3

Zero points and reference points

Various zero points and reference points are defined on an NC machine:
Zero points
Reference points
Fundamentals
Programming Manual, 09/2011, 6FC5398-1BP40-2BA0
M Machine zero
The machine zero defines the machine coordinate system (MCS). All other reference
points refer to the machine zero.
W Workpiece zero = program zero
The workpiece zero defines the workpiece coordinate system in relation to the
machine zero.
A Blocking point
Can be the same as the workpiece zero (only for lathes).
R Reference point
Position defined by output cam and measuring system. The distance to the machine
zero M must be known so that the axis position at this point can be set exactly to this
value.
B Starting point
Can be defined by the program. The first machining tool starts here.
T Toolholder reference point
Is on the toolholder. By entering the tool lengths, the control calculates the distance
between the tool tip and the toolholder reference point.
N Tool change point
Fundamental Geometrical Principles
1.3 Zero points and reference points
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