HEIDENHAIN TNC 640 (34059x-05) ISO programming - Manual (Page 568)

Test run and program run
17.5 Program run
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TNC 640 | User's ManualDIN/ISO Programming | 1/2015
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.
Example
The power failed while a thread cutting cycle in the tilted working
plane was being performed. You have to retract the tap:
Switch on the power supply for control and machine. The TNC
starts the operating system. This process may take several
minutes. Then the TNC will display the message "Power
interrupted" in the screen header
Activate the Retraction mode: Press the RETRACT
soft key. The TNC displays the message RETRACT.
Acknowledge the power interruption: Press the CE
key. The TNC compiles the PLC program.
Switch on the control voltage: The TNC checks
the functioning of the EMERGENCY STOP circuit.
If at least one axis is not referenced, you have to
compare the displayed position values with the
actual axis value and confirm their agreement.
Follow the dialog, if required.
Check the preselected traversing mode: if required, select
THREAD
Check the preselected thread pitch: if required, enter the thread
pitch
Check the preselected direction of rotation: if required, select
the direction of thread rotation.
Right-handed thread: The spindle turns in clockwise direction
when moving into the workpiece and counterclockwise when
retracting
Left-hand thread: The spindle turns in counterclockwise
direction when moving into the workpiece and clockwise when
retracting
Activate retraction: Press the RETRACT soft key