HEIDENHAIN TNC 620 User Manual page 405

Automatically retract tool from the contour at an NC
stop: M148
Standard behavior
At an NC stop the TNC stops all traverse movements. The tool
stops moving at the point of interruption.
Behavior with M148
The M148 function must be enabled by the machine
tool builder. The machine tool builder defines in
a machine parameter the path that the TNC is to
traverse for a LIFTOFF command.
Set the parameter Y in the LIFTOFF column of the tool table for the
active tool. The TNC then retracts the tool from the contour by up
to 2 mm in the direction of the tool axis.
Further Information: "Enter tool data into the table", page 200
LIFTOFF takes effect in the following situations:
An NC stop triggered by you
An NC stop triggered by the software, e.g. if an error occurred
in the drive system
When a power interruption occurs
Danger of collision!
Remember that, especially on curved surfaces, the
surface can be damaged during return to the contour.
Retract the tool before returning to the contour!
In the CfgLiftOff (no. 201400) machine parameter,
define the value by which the tool is to be retracted.
In the CfgLiftOff (no. 201400) machine parameter
you can also switch the function off.
Effect
M148 remains in effect until deactivated with M149.
M148 becomes effective at the start of the block, M149 at the end
of the block.
HEIDENHAIN | TNC 620 | ISO Programming User's Manual | 9/2016
Miscellaneous functions for path behavior 10.4
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