Allen-Bradley 1747-PBASE, Руководство по программированию

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Publication 1746-PM001A-US-P
Writing Programs Using the BASIC Development Language 6-9
Example:
A programming macro is written to set the wall clock’s day, month, and year. The
macro is named Setdate and is defined by the BASIC lines between
{$MACRO...}
and
{$ENDM}
. After the programming macro is defined, it can be called again any
number of times, anywhere in that program, by simply programming the name
Setdate.
Example:
Before translation:
After translation:
REM CREATE PROGRAM MACRO 0 REM ...
{$MACRO Setdate(%1, %2, %3)} 1O REM CREATE PROGRAM MACRO
PUSH %1 20 D=16
PUSH %2 30 M=06
PUSH %3 40 Y=90
CALL 41 50 PUSH D
{$ENDM} 60 PUSH M
D=16 70 PUSH Y
M=06 80 CALL 41
Y=90
Setdate(D,M,Y)
If you have a large number of your own programming macros or a number of them
that you use frequently, you may wish to create a file containing only those macros.
You could then include that file in all of your programs. For example, if you made
a programming macro file named
mine.bdl
, you could then begin all of your
programs with the command
{$I Mine.bdl}.
This would include that file
during translation and allow you to use your programming macros throughout the
program.
Bringing in Programs
from Separate Files Depending on the circumstances, you may want to access other programs from
your program, or you may wish to copy other programs directly into your program.
There are several methods for accomplishing this.
When choosing between accessing a program as a subprogram or inserting it into
your main program, consider the following:
•
the size of the program you wish to access or insert
•
the frequency with which you need to execute it from your main program
•
whether it is or may be used as a subprogram for other programs
•
whether inserting it makes your main program unmanageably large
IMPORTANT
If you are unable to merge or edit files, those files have probably
been locked. Files can be locked (made read-only) or unlocked
through the
Information about current file
option from
the File menu.