HEIDENHAIN TNC 620 User Manual page 581

Any entry into program: Mid-program startup
Danger of collision!
If you use the GOTO key and the number of the NC
block for going into a program, neither the TNC nor
the PLC will execute any functions that ensure a safe
start.
For safe entry, always use the BLOCK SCAN function.
The BLOCK SCAN function must be enabled and
adapted by the machine manufacturer. Refer to your
machine manual.
With the BLOCK SCAN function you can start an NC program at any
desired NC block. The control factors workpiece machining up to
this NC block into the calculations.
You can run the mid-program startup in the following ways:
Mid-program startup in the main program, with repetitions if
necessary
Multi-level mid-program startup in subprograms and touch probe
cycles
Mid-program startup in a point table
Block scan in pallet programs
At the start of mid-program startup the control resets all data,
as with a selection of the NC program. During the mid-program
startup you can change between Program run full sequence and
Program run single block.
The TNC skips all touch probe cycles in a
midprogramstartup. Result parameters from these
cycles might therefore remain empty. If you wish to
continue working with the results of a touch probe
cycle, use the multi-level mid-program startup.
You must not use mid-program startup if you:
The stretch filter is activated
use the touch probe cycle G55 in the search
phase of the mid-program startup
HEIDENHAIN | TNC 620 | ISO Programming User's Manual | 9/2016
Program run 16.5
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