HEIDENHAIN TNC 128 (77184x-02) - Manual (Page 337)

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TNC 128 | User's Manual HEIDENHAIN Conversational Programming | 5/2014
337
Retraction after a power interruption
The
Retraction mode of operation must be enabled
and adapted by the machine tool builder. Refer to
your machine manual.
With the
Retraction mode of operation you can disengage the tool
from the workpiece after an interruption in power.
The
Retraction mode of operation is selectable in the following
conditions:
Power interruption
Relay external DC voltage missing
Traverse reference points
The Retraction operating mode offers the following modes of
traverse:
Mode Function
Machine axes Movement of all axes in the original
coordinate system
Tool axis Movements of the tool axis in the active
coordinate system
Thread Movements of the tool axis in the active
coordinate system with compensating
movement of the spindle
Effective parameters: Thread pitch and
direction of rotation
The TNC selects the mode of traverse and the associated
parameters automatically. If the traverse mode or the parameters
were not correctly chosen, you can change them manually.
Danger of collision!
For nonreferenced axes, the TNC adopts the most
recently saved axis values. These values generally
are not the exact actual axis positions!
As a result, for example, the tool might not move
exactly along the actual tool direction. If the tool
is still in contact with the workpiece, it can cause
stress or damage to the tool and workpiece. Stress
or damage to the workpiece or tool can also be
caused by uncontrolled coasting or braking of axes
after a power interruption. Move the axes carefully if
the tool is still in contact with the workpiece. Set the
feed rate override to the smallest values possible. If
you use the handwheel, use a small feed rate factor.
The traverse range monitoring is not available for
nonreferenced axes. Observe the axes while you
move them. Do not move to the limits of traverse.