(4) When the predetermined conditions specified in the system are satisfied and the program is
changed over by the system.
The task change-over conditions specified in the system are as follows:
(1) A program in a task is executed for more than 50 msec.
(2) When the data area for movement command becomes full.
Up to four data can be read beforehand by the movement command. If this internal area
for prior reading becomes full, the task is changed over.
(3) When the command requiring communication with an external device has been executed.
The INPUT, PRINT and RESTORE commands are not executed alone by the SCOL
program. They are the commands including such processing as the TP operation by an
operator and RAM file operation. If the system waits for a reply, therefore, the task is
changed over.
To avoid the task change-over by the system, set the system variable SWITCH to
“DISABLE”.
Note: If the task change-over is prohibited, only currently active program is executed and the
other task program which has already started is not executed (single task operation).
If the global variable which can be referred to from the entire program is defined, obey the following
rules.
(1) Global variable declaration
If the global variable is used, the type and identifier (variable name) of the variable to be
used is required to be defined.
This definition must be performed before the first PROGRAM statement.
To define the variable A of real number type and the variable B of integer type, the definition
is as follows:
GLOBAL
A = 1.0 (This value is the initial value of the variable.)
B = 2
END
PROGRAM
:
END