16. CUSTOM MACRO
When an M99 block consists only of address O, N, P, L, or
M, this block is regarded as belonging to the previous block
in the program. Therefore, a single–block stop does not
occur for this block. In terms of programming, the following
and are basically the same. (The difference is
whether Gff is executed before M99 is recognized.)
Gff Xfff ;
Gff Xfff M99 ;
A custom macro interrupt is different from a normal program call. It is
initiated by an interrupt signal (UINT) during program execution. In
general, any modifications of modal information made by the interrupt
program should not affect the interrupted program.
For this reason, even when modal information is modified by the interrupt
program, the modal information before the interrupt is restored when
control is returned to the interrupted program by M99.
When control is returned from the interrupt program to the interrupted
program by M99 Pxxxx, modal information can again be controlled by
the program. In this case, the new continuous information modified by
the interrupt program is passed to the interrupted program. Restoration of
the old modal information present before the interrupt is not desirable.
This is because after control is returned, some programs may operate
differently depending on the modal information present before the
interrupt. In this case, the following measures are applicable:
(1)The interrupt program provides modal information to be used after
control is returned to the interrupted program.
D Custom macro interrupt
and modal information