Programming instructions

3-28
Motion Commands, Dimension Inputs NC Programming 17VRS
DOK-MTC200-NC**PRO*V17-ANW1-EN-P
Cancel All Feeds to Positive Stop 'G76'
The preparatory command G76 cancel all axes at positive stop causes
the pre-loads on all pre-loaded axes to be canceled. The actual position
value is used as the position command value so that the axis positions
can be used as reference positions for further traverse moves. The dis-
tance-to-go is ignored.
G76
•
G76 is active only for the NC-block in which it is located.
•
The preparatory command G76 cannot be programmed together with
axis data. G76 cancels the axis pre-loads on all axes which are pre-
loaded using G75 Feed to Positive stop.
•
If a program is terminated by the NC command RET, by a branch with
stop BST, when the NC-program is manually reset via Control-Reset,
or if there is a power failure, all axis preloads are automatically can-
celed.
3.13 Reposition and NC Block Restart
The functions
•
reposition and
•
NC-block restart
automate traversing back to the contour following a program interruption.
After program interruptions in which the operator withdrew the tool from
the contour in manual mode—to check and replace the inserts on the
tool, for example—the reposition function allows the operator to return to
the point of interruption, and the NC-block restart function allows him to
traverse back to the starting point of the NC-block.
Both functions are available in the manual and program-driven modes. In
manual mode the controller compensates for the difference between the
target position and the actual position in the order in which the user
presses the jog keys. In the program-driven modes, the axis are traversed
to their destination positions in the order which is programmed by the ma-
chine builder in an NC subroutine.
Reposition and NC Block Restart in the Automatic Operating Modes
Operators frequently use reposition and return to NC-block in manual
mode only in order to return the axes to the vicinity of the contour. Once
the possibility of collisions occurring is eliminated, the operators change to
one of the automatic operating modes, Automatic, Semiautomatic or Exe-
cute Program in Manual Mode, and there they continue repositioning or
NC-block restart by pressing the Start key.
By changing to a programmed-controlled operating mode well enough in
advance, tool racing and tool racing marks on the workpiece can be
avoided. Following repositioning or NC-block restart, the NC resumes
program execution without performing a new NC start.
Syntax
Notes on programming G76