HEIDENHAIN CNC Pilot 4290 - Manual (Page 192)

4 DIN PLUS 180
Example:
. . .
N.. IF {E1[16]==1}
N..THEN
N.. G0 X100 Z100
N.. ELSE
N.. G0 X0 Z0
N.. ENDIF
. . .
■ NC blocks with IF, THEN, ELSE, ENDIF
can have no further commands
■ For branches due to V variables or
events, the contour follow-up is switched
off with the IF statement and back on with
the ENDIF statement. With G703 you can
switch on the contour follow-up function.
4.15
V
a
riable Pr
ogr
amming
Example:
. . .
N.. WHILE (#4<10) AND (#5>=0)
N.. G0 Xi10
. . .
N.. ENDWHILE
. . .
■ If the repetition is made due to V
variables or events, the contour follow-up
function is switched off for the WHILE
branch and switched on again with
ENDWHILE. With G703 you can switch on
the contour follow-up function.
■ If the ”condition” you program in the
WHILE command is always true, the pro-
gram remains in an ”endless loop.” This is
one of the most frequent causes of error
when working with program repeats.
WHILE..ENDWHILE – program repeat
A ”program repeat” consists of the elements:
■ WHILE – followed by a condition. In the case of ”conditions”,
variables or mathematical expressions are defined to the left and to
the right of relational operators.
■ ENDWHILE – concludes the conditional program branch.
NC blocks programmed between WHILE and ENDWHILE are
executed repeatedly for as long as the ”condition” is fulfilled. If the
condition is not fulfilled, CNC PILOT continues execution of the
program with the block programmed after ENDWHILE.
Programming notes
Select WHILE (Machining menu: Instructions – DIN PLUS words)
Enter the desired condition (enter only the required brackets).
Insert NC blocks
IF..THEN..ELSE..ENDIF – program branches
A ”conditional branch” consists of the elements:
■ IF – followed by a condition. In the case of conditions, variables or
mathematical expressions are defined to the left and to the right of
relational operators.
■ THEN – when the condition is fulfilled, the THEN branch is
executed.
■ ELSE – when the condition is not fulfilled, the ELSE branch is
executed.
■ ENDIF – concludes the conditional program branch.
Programming notes
Select IF (Machining menu: Instructions – DIN PLUS words)
Enter the desired condition (only enter the required brackets).
Insert NC blocks of the THEN and ELSE branch – the ELSE branch
can be omitted