4 PLC configuration
4.1 Task configuration
Modular PLCs XControl: XC-104-…, XC-204-…, XC-303-… 01/23 MN050005EN Eaton.com 73
4 PLC configuration
4.1 Task configuration
Processing of the project can be controlled via tasks. Each task can be
assigned with a range of programs which should be run during execution of
the task..
The task is defined by a name, a priority and a type which defines under
which conditions a task starts. Priority and task conditions determine the
sequence in which the tasks are to be processed.
You can select "cyclical" or "event-triggered" as the task condition. A cyclical
task is restarted after the set interval time has elapsed. An event-triggered
task is only started when the event occurs. You can also link system events
such as "Start", "Stop" or "Reset" with the execution of a program.
The task priorities can be parameterized with a value from 0 to 31 where 0 is
the highest priority and 31 is the lowest priority.
In principle the output image is written onto the physical outputs before
every task is called and the map is read by the inputs (updating of the input/
output map). The task is executed thereafter. In addition, all system activities
are carried out before or after the task call. This includes for example, com-
munication with the XSOFT-CODESYS-3 or Online changes.
Updating of the input/output image by multiple tasks is described in the Sec-
tion “Multi-tasking” on Page 77.
All IEC tasks, including those with the highest priority can be interrupted by
an interrupt or an event controlled task.
Time monitoring (Watchdog) can be activated for each task.
Following is an example used to illustrate the PLC-specific settings.
Creating a task (example)
First create the cyclic task “Basic” with the assigned program “Basic_prog”.
Then you can add the event-triggered "Param" task with the "Param_prog"
program. In the program “Basic_prog” an event is programmed which
invokes the “Param” task.
The following steps are necessary in order to create a task:
• Add a task
• Define the program call
• Create the program
￫
For a detailed task configuration description, please refer to the
manual for programming PLCs with XSOFT-CODESYS-3
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