HEIDENHAIN TNC 620 User Manual page 115

Fundamentals | NC fundamentals
Machine coordinate system M-CS
The machine coordinate system corresponds to the description of
kinematics and therefore to the actual mechanical design of the
machine tool.
Because the mechanics of a machine tool never precisely
correspond to a Cartesian coordinate system, the machine
coordinate system consists of several one-dimensional coordinate
systems. These one-dimensional coordinate systems correspond to
the physical machine axes that are not necessarily perpendicular to
each other.
The position and orientation of the one-dimensional coordinate
systems are defined with the aid of translations and rotations based
on the spindle tip in the description of kinematics.
The position of the coordinate origin, the machine datum, is defined
by the machine manufacturer during machine configuration. The
values in the machine configuration define the zero positions of
the encoders and the corresponding machine axes. The machine
datum does not necessarily have to be located in the theoretical
intersection of the physical axes. It can therefore also be located
outside of the traverse range.
Because the machine configuration values cannot be modified by
the user, the machine coordinate system is used for determining
constant positions, e.g. the tool change point.
Soft key Application
The user can define shifts in the machine coordinate
system according to the specific axis with use of the
OFFSET values of the preset table.
The machine tool builder configures the OFFSET columns
of the preset management in accordance with the
machine.
Further information: "Preset management", Page 192
Danger of collision!
Your control may feature an additional pallet preset table,
depending on the machine. In this table the machine tool builder
can define OFFSET values that take effect before the OFFSET
values you specify in the preset table become effective. The PAL
tab of the additional status display indicates whether a pallet
preset is active, and which one. Since the OFFSET values of the
pallet preset table are neither shown nor editable, there is a risk of
collision during all movements!
Refer to the machine tool builder's documentation
Use pallet presets only in conjunction with pallets
Check the display of the PAL tab before you start machining
HEIDENHAIN | TNC 620 | User's Manual for Setup, Testing and Running NC Programs | 01/2022
NOTICE
3
Machine datum (MZP)
115