Lenze PLC Designer PLC Designer (R3-1) - Manual (Page 772)

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General Editors
770 DMS 4.1 EN 03/2011 TD29
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13.16 Task Editor
13.16.1 Task Configuration
The Task Configuration defines one or several tasks for controlling the processing of an
application program. Thus it is an essential resource object for an application and must
be available in the Devices window.
In contrast to »PLC Designer« 2.3 the tree structure of the Task Configuration is not
viewed and handled within the editor window, but is integrated in the resources tree
in the Devices window. It is an obligate resource object for each application and can be
added via the Add Object command.
At the topmost position of a task configuration tree there is the entry " Task
configuration". Below there are
t he currently defined tasks, each represented by the
task name. The POU calls of the particular tasks are not displayed in the task
configuration tree.
The task tree can be edited (tasks can be added, copied, pasted or removed) by the
appropriate commands usable for the devices tree. For example for adding a new task
use command 'Add Object' .
The particular tasks can be configured in the Task Editor dialogs which additionally
provide a monitoring view in online mode. The options available for a task
configuration are target-specific.
Abb. 420 Task Configuration in Devices Tree below an Application
A Task is a time unit in the processing of an IEC program. It is defined by a name, a
priority and by a type determining which condition will trigger the start of the task.
This condition can be defined by a time (cyclic, freewheeling) or by an internal or
external event which will trigger the task; for example the rising edge of a global
project variable or an interrupt event of the controller.
For each task you can specify a series of program POUs that will be started by the task.
If the task is executed in the present cycle, these programs will be processed for the
length of one cycle.
The combination of priority and condition will determine in which chronological order
the tasks will be executed.
For each task you can configure a watch dog (time control); the possible settings
depend on the target system.
Additionally there is the possibility to link System events (for example Start, Stop,
Reset) directly with the execution of a project POU.
In online mode the task processing can be monitored.