CJ2 CPU Unit Software User's Manual - CIP ETI

5 Understanding Programming Tasks and the Execution CycleA cyclic task (including an extra cyclic task) that is in READY status will maintain that status in subsequentcycles.TASK ONinstructionCyclic task 1Cyclic task 2READYstatus atthe start ofoperationREADYstatusCyclic task 1Cyclic task 2READYstatusREADYstatusA cyclic task that is in STANDBY status will maintain that status in subsequent cycles. The task willhave to be turned ON using a TASK ON instruction in order to switch from STANDBY status toREADY status.TASK OFFinstructionTASK ONinstructionCyclic task 1Cyclic task 2STANDBYstatusREADYstatusCyclic task 1Cyclic task 2STANDBY statusREADY statusIf a TASK OFF instruction is executed for its own task, the task will stop being executed where theTASK OFF instruction is executed, and the task will change to STANDBY status.Task 2TKOF 2Task execution willstop here and thetask will change toSTANDBY status.Cyclic Task Numbers and the Execution Cycle• If task m turns ON task n and m > n, task n will go to READY status at the next cycle.Example: If task 5 turns ON task 2, task 2 will go to READY status at the next cycle.• If task m turns ON task n and m < n, task n will go to READY status in the same cycle.Example: If task 2 turns ON task 5, task 5 will go to READY status in the same cycle.• If task m places task n in STANDBY status and m > n, will go to STANDBY status the next cycle.Example: If task 5 places task 2 in STANDBY status, task 2 will go to STANDBY status the nextcycle.• If task m places task n in STANDBY status and m < n, task n will go to STANDBY status in thesame cycle.Example: If task 2 places task 5 in STANDBY status, task 5 will go to STANDBY status in thesame cycle.5-18 CJ2 CPU Unit Software User’s Manual