NCT Group NCT 990T manual Unconditional Restart of Automatic Operation, Interrupting Single Blocks

13.3 Unconditional Restart of Automatic Operation

13.3 Unconditional Restart of Automatic Operation

If automatic operation is started from interrupted state (INTD) unconditionally after START the control goes to the end position of the interrupted block and carries on machining from there. The typical applications of the function are as follows:

–the errors must be canceled, than the machining continued when error messages are coming from program module preprocessor or PLC,

–during machining parameters of cutting may need to be repaired, for example if spindle speed (S) or feedrate (F) must be overwritten by means of manual data input, than the machining continued,

–in more simple cases the end position or measure data is to be modified without repairing the part program,

–if in course of the machining an obstacle, for example a workpiece clamp is in the way of tool path it needs to be rounded, than the cutting continued.

Interrupting Single Blocks

1st case: in state G40 interruption of linear interpolation parallel to an axis Let us examine fragments of the following sample programs:

Program No. 1:		Program No. 2:
...	G90 G0 X20 Z0	...	G90	G0 X20 Z0
N60		N60
N70	X120	N70	G91	X100
N80	Z–30	N80	Z–30
...		...

Programs No. 1 and 2 are on the same tool path, how- ever the data specification of the former one is absolute, while that of the latter one is incremental. The interrup-

tion occurs in block N70. In position X=60, Z=0 the movement is stopped, the automatic mode is interrupted

and the slides are carried to position X=80, Z=20 by means of manual operation. If afterwards the automatic mode is returned, and the START button is pressed the

movement programmed in block N70 is finished. X axis

moves to the programmed position X=120, no matter if the tool path has been written by the use of absolute

data specification (program No. 1) or incremental data

specification (program No.2). The Z axis does not move in block N70, it only returns to the programmed original tool path in block N80, where movement Z is programmed. In case Z axis is not referred to in more subsequent blocks it only returns to the programmed path in the block, in which reference to address Z takes place.

The movement is the same, if in single block mode the automatic operation is closed in the start position of block N70, manual operation is used, than after return the START button is pressed.

103