HEIDENHAIN TNC 620 Programming Station, User Manual

Page: 390 / 695

Miscellaneous functions
10.3 Miscellaneous functions for coordinate entries
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HEIDENHAIN | TNC 620 | ISO Programming User's Manual | 9/2016
Behavior with M92 – Additional machine datum
In addition to the machine datum, the machine tool
builder can also define an additional machine-based
position as a reference point.
For each axis, the machine tool builder defines the
distance between the machine datum and this
additional machine datum. Refer to your machine
manual.
If you want the coordinates in positioning blocks to be based on the
additional machine datum, end these block with M92.
Radius compensation remains the same in blocks
that are programmed with M91 or M92. The tool
length is
not included.
Effect
M91 and M92 are effective only in the blocks in which M91 and
M92 have been programmed.
M91 and M92 take effect at the start of block.
Workpiece datum
If you want the coordinates to always be referenced to the machine
datum, you can block datum setting for one or more axes.
If datum setting is inhibited for all axes, the TNC no longer
displaysthe
DATUM SET
in the
Manual operation
mode.
The figure shows coordinate systems with the machine and
workpiece datum.
M91/M92 in the Test Run mode
In order to be able to graphically simulate M91/M92 movements,
you need to activate working space monitoring and display the
workpiece blank referenced to the set datum.
Further Information: "Show the workpiece blank in the working
space (option 20)", page 566