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Miscellaneous functions for path behavior 10.4 – HEIDENHAIN TNC 640 (34059x-04) ISO programming User Manual

Page 345

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Miscellaneous functions for path behavior 10.4

10

TNC 640 | User's Manual for DIN/ISO Programming | 3/2014

345

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.

The TNC retracts the tool from the contour by up to 2 mm in the
direction of the tool axis if, in the

LIFTOFF column of the tool table,

you set the parameter

Y for the active tool. See "Enter tool data

into the table", page 164.
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 machine parameter, define the

value by which the tool is to be retracted. In the

CfgLiftOff 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 block, M149 at the end of

block.