Omron CP - PROGRAMMING MANUAL 05-2007 - Page 92

59
Using Tasks Section 2-2
Note At least one cyclic task must be in READY status in each cycle. If there is not
cyclic task in READY status, the Task Error Flag (A295.12) will turn ON, and
the CPU Unit will stop running.
Tasks and the
Execution Cycle
A cyclic task (including an extra cyclic task) that is in READY status will main-
tain that status in subsequent cycles.
Cyclic task 1
Cyclic task 2
Cyclic task 3
Cyclic task 1
Cyclic task 2
Cyclic task 3
Cyclic task 0
Cyclic task 1
Cyclic task 2
Cyclic task 3
Cyclic task 0
Cyclic task 3
Cyclic task 0
1) Task 0 will be
in READY
status at the
start of opera-
tion.
Other tasks will re-
main in Disabled
status.
2) Task 1 will go to
READY status if A is
ON, and tasks 2 and
3 will remain on
Disabled status.
READY status
Standby status/Disabled status
3) Task 0 will go to
Standby status if D
is ON.
Other tasks will remain in
their current status.
Example: Cyclic Task
Cyclic task 0
(READY status
at the start of
operation)
Cyclic task 1
Cyclic task 2
Cyclic task 1
Cyclic task 2
Cyclic task 1
Cyclic task 2
READY status
READY status
READY sta-
tus at the
start of op-
eration
READY
status
TKON(820)