The maximum number of tasks you can define for the Modicon M218 Logic Controller are:
oTotal number of tasks = 7
oCyclic tasks = 3
oFreewheeling tasks = 1
oEvent tasks = 2
oExternal Event tasks = 4
NOTE: The total number of Freewheeling task, Cyclic tasks, and Event tasks must not be greater than 3.
Special Considerations for Freewheeling
A Freewheeling task does not have a fixed duration. In Freewheeling mode, each task scan starts when the previous scan has been completed and after a period of system processing (30% of the total duration of the Freewheeling task). If the system processing period is reduced to less than 15% for more than 3 seconds due to interruptions by other tasks, a system error is detected. For more information, refer to the System Watchdog.
NOTE: You may wish to avoid using a Freewheeling task in a multi-task application when some high priority and time-consuming tasks are running. Doing so may provoke a task Watchdog Timeout.
