NCT Group NCT 990T - Manual (Page 103)

13.3 Unconditional Restart of Automatic Operation
103
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
1 st case: in state G40 interruption of linear interpolation parallel to an axis
Let us examine fragments of the following sample programs:
Program No. 1:
...
N60 G90 G0 X20 Z0
N70 X120
N80 Z–30
...
Program No. 2:
...
N60 G90 G0 X20 Z0
N70 G91 X100
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.