Specifications

4-4
4.1 Overview of Program Configuration
4.1.3 Tasks
4.1.3 Tasks
A task is an element that contains multiple POUs, and it is registered to a program file.
One or more programs of POU need to be registered in a task. (Functions and function blocks
cannot be registered in a task.)
(1) Task executing condition
The executing conditions in a programmable controller CPU are set for each task that is
registered to program files. Executing processes are determined for each task by setting the
executing condition.
The following are the types of task executing condition.
(a) Always (Default executing condition)
Executes registered programs for each scan.
(b) Event
Executes tasks when values are set to the corresponding devices or labels.
(c) Interval
Executes tasks in a specified cycle.
A priority can be set for each task execution.
● Priority
When executing conditions of multiple tasks are met simultaneously, the tasks are
executed according to the set priority.
Tasks are executed in the order from the smallest priority level number.
Tasks set with a same priority level number are executed in the order of task data name.
Tas kTaskTas kTask
Tas kTask
Tas kTask
Tas kTask
Project
Program file 2
POU
Program
POU
Program
POU
Program
Tas k
Program file 1
POU
Program
POU
Program
Tas k
POU
Program
POU
Program
Tas k
Program file n
POU
Program
POU
Program
Tas k
POU
Program
Tas k