ISPSoft User Manual The execution of the freewheeling task continues since the high-priority cyclic task request has not arrived. The cyclic task interrupts the freewheeling task execution and the controller executes the cyclic task because of the arrival of the high-priority cyclic task request during the execution of the freewheeling task. The controller continues to execute the part of the low-priority freewheeling task, which has not been executed yet when the execution of the cyclic task is completed. When the execution of the freewheeling task is completed, the controller executes the system processing due to no other task request.
When the system processing is completed, the execution of the freewheeling task continues due to no high-priority cyclic task request.
Executing mixture of three tasks (Event, Cyclic and Freewheeling task) Task execution time Priority High Task trigg ered by e ve nt ( ) P rio rit y 1 condition met 9 finished Task executi on tim e Task execution time Task execution time Fre ewh eelin g task ( ) Priority 2 2 4 5 6 Task execution finished Task execution condition met Task execution finished 10 12 Task execution condition met Task execution finished Task execution condition met Task execution condition met Cyclic task (Priority 3) Low Syst em p ro cessing When the conditions for execution of the freewheeling task and cyclic task are both met, the freewheeling task is executed first because the priority of the freewheeling task is higher.
The cyclic task execution starts when the freewheeling task execution is completed. When the cyclic task execution is completed, the controller executes the system processing due to no other task request. The freewheeling task is executed when the system processing is completed. When the freewheeling task execution is completed, the controller executes the system processing due to no other task request. The freewheeling task is executed when the system processing is completed. The freewheeling task execution continues because the freewheeling task has a higher priority than the cyclic task although the execution condition for the cyclic task is met.
And the cyclic task waits to execute. 5-10 The event task has not been triggered IO User program 8 Task execution tim IO User program Pause User program IO User program 1 IO User program IO User program Time interva l between tasks Time interval between tasks User Pause IO program 7 11 Task execution Task execution condition met finished System n g processi ween tasks Time interval between Pause IO User program ng pr Pause IO User program ng System ocessi Syste m oce ssi System ocessi