HEIDENHAIN TNC 426, User Manual

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412 11 Test run and Program Run
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Mid-program startup (block scan)
With the RESTORE POS AT N feature (block scan) you can start a part
program at any block you desire. The TNC scans the program blocks
up to that point. Machining can be graphically simulated.
If you have interrupted a part program with an INTERNAL STOP, the
TNC automatically offers the interrupted block N for mid-program
startup.
The RESTORE POS AT N feature must be enabled and
adapted by the machine tool builder. Refer to your
machine manual.
Mid-program startup must not begin in a subprogram.
All necessary programs, tables and pallet files must be
selected in a program run mode of operation (status M).
If the program contains a programmed interruption before
the startup block, the block scan is interrupted. Press the
machine START button to continue the block scan.
After a block scan, return the tool to the calculated position
with RESTORE POSITION.
If you are working with nested programs, you can use
machine parameter 7680 to define whether the block scan
is to begin at block 0 of the main program or at block 0 of
the last interrupted program.
If the working plane is tilted, you can use the 3-D ON/OFF
soft key to define whether the TNC is to return to the
contour in a tilted or in a non-tilted coordinate system.
The function M128 is not permitted during a mid-program
startup.
If you want to use the block scan feature in a pallet table,
select the program in which a mid-program startup is to be
performed from the pallet table by using the arrow keys.
Then press the RESTORE POS AT N soft key.
All touch probe cycles and the Cycle 247 are skipped in a
mid-program startup. Result parameters that are written
to from these cycles might therefore remain empty.