Programming manual M238 | 3 MB - BERGER - POSITEC

Default Task Configuration
Tasks
Default Task Configuration
For the Modicon M238 Logic Controller:
The MAST task can be configured in Freewheeling or Cyclic mode. The MAST
task is automatically created by default in Cyclic mode. Its preset priority is
medium (15), its preset interval is 20 ms, and its task watchdog service is
activated with a time of 100 ms and a sensitivity of 1. Refer to Task Priorities
(see page 39) for more information on priority settings. Refer to System and Task
Watchdogs (see page 38) for more information on watchdogs.
Designing an efficient application program is important in systems approaching the
maximum number of tasks. In such an application, it can be difficult to keep the
resource utilization below the system watchdog threshold. If priority reassignments
alone are not sufficient to remain below the threshold, some lower priority tasks can
be made to use fewer system resources if the SysTaskWaitSleep function is added
to those tasks. For more information about this function, see the optional SysTask
library of the system / SysLibs category of libraries.
NOTE: Do not delete or change the Name of the MAST task. If you do so,
SoMachine detects an error when you attempt to build the application, and you will
not be able to download it to the controller.
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