Calculating Guidelines For The Real Processing Times Of Tasks; A-2-1 Calculating The Average Real Processing Times Of Tasks; Calculating The Average Real Processing Times Of Tasks - Omron NJ-series User Manual

A-2 Calculating Guidelines for the Real
Processing Times of Tasks
This section describes how to calculate guidelines for the average real processing times of tasks on
paper.
You must use the physical Controller to check the real processing times of tasks and task execution
times. For details, refer to 5-3 Task Design Methods and I/O Response Times.
Precautions for Safe Use
The execution times in the physical Controller depends on the logic operations that are per-
formed in the user program, the presence of communications commands and data links, on
whether data tracing is performed, and on other factors.
Before starting actual operation, you must test performance under all foreseeable conditions on
the actual system and make sure that the task periods are not exceeded and that suitable com-
munications performance is achieved.
Additional Information
Periodic tasks will be interrupted for the execution of tasks with higher execution priorities. The
real processing time of a task does not include the time for which the task is interrupted. It is the
task execution time that gives the actual time from when the task is started until it is finished,
including the interrupted time. For a detailed description of the differences between the real pro-
cessing times of tasks and the task execution times, refer to Meaning of the Task Execution Time
and the Real Processing Time of the Task on page 5-50.
A-2-1

Calculating the Average Real Processing Times of Tasks

The average real processing time of a task is the total of the I/O refresh processing time, user program
execution time, motion control processing time and common processing time.
Average real processing time of task = I/O refresh processing time + User program execution time +
The following processing is performed.
Processing
I/O refresh processing
User program execution
Motion control processing
NJ-series CPU Unit Software User's Manual (W501)
Motion control processing time + Common processing time
Processing contents
I/O is refreshed for CJ-series Units
(Basic I/O Units, Special I/O Units, and
CPU Bus Units) and EtherCAT slaves.
• Programs assigned to tasks are exe-
cuted in the order that they are
assigned.
• Motion control commands from the
user program are executed.
• Motion control outputs are processed.
Appendices
Priority-17
Primary Priority-16
and prior-
periodic periodic
ity-18 peri-
task task
odic tasks
Performed. Performed. Not per-
formed.
Performed. Performed. Performed.
Performed. Not per- Not per-
formed. formed.
A-13