Omron NJ Series

5 Designing Tasks
5-12
NJ-series CPU Unit Software User’s Manual (W501)
Note The processes in each cell in the above table are executed in the order of description.
Periodic Tasks That Control I/O
Note The processes in each cell in the above table are executed in the order of description.
Processing Processing contents
System common processing 1 • Processing for exclusive control of variables in tasks (when accessing
tasks are set)
• Data trace processing (sampling and trigger checking) is performed.
User program execution • Programs assigned to tasks are executed in the order that they are
assigned.
System common processing 2 • Processing for exclusive control of variables in tasks (when refreshing
tasks are set)
• Processing for variables accessed from outside of the Controller is per-
formed to maintain concurrency with task execution (executed for the
variable access time that is set in the Task Settings).
• If there is processing for EtherNet/IP tag data links and refreshing tasks
are set for the tags (i.e., variables with a Network Publish attribute), vari-
able access processing is performed.
Processing Processing contents
I/O refreshing Output data
processing
• Output refresh data is created for Output Units that refresh I/O.
• If forced refreshing is set, the forced refreshing values are reflected in the
output refresh data.
Refreshing • This process exchanges data with I/O.
Input data
processing
• Input refresh data is loaded from Input Units that refresh I/O.
• If forced refreshing is set, the forced refreshing values are reflected in the
input refresh data that was read.
System common processing
1
• Processing for exclusive control of variables in tasks (when accessing
tasks are set)
• Data trace processing (sampling and trigger checking) is performed.
User program execution • Programs assigned to tasks are executed in the order that they are
assigned.
System common processing
2
• Processing for exclusive control of variables in tasks (when refreshing
tasks are set)
• Processing for variables accessed from outside of the Controller is per-
formed to maintain concurrency with task execution (executed for the vari-
able access time that is set in the Task Settings).
• If there is processing for EtherNet/IP tag data links and refreshing tasks are
set for the tags (i.e., variables with a Network Publish attribute), variable
access processing is performed.
User
program
execution
Refreshing
System
common
processing 2
System
common
processing 1
Input data
processing
Output data
processing
Control processing
I/O refreshing
* The Controller will pause the
execution of a periodic task in
order to execute a task with a
higher execution priority.
Task execution time (varies)
Task period (fixed)
*
*