Omron NJ Series User Manual

5 Designing Tasks
5-10
NJ-series CPU Unit Software User’s Manual (W501)
The relationship between CPU Unit operating modes and tasks is given in the following table.
Precautions for Correct UsePrecautions for Correct Use
• Even if the execution condition for an event task is already met when you change the operating
mode to RUN mode, the event task will not be executed. An event task is executed only when
its execution condition changes from not met to met during RUN mode.
• Even in RUN mode, an event task is not executed if there is a major fault level error.
 Primary Periodic Task
The primary periodic task has the highest execution priority. It executes processes with high speed
and high precision.
In every period, this task performs system common processing, I/O refreshing, user program execu-
tion, and motion control. Unlike periodic tasks, the primary periodic task performs motion control
processing (MC).
Tasks and Operating Modes
Task Specification
Primary periodic task • These tasks are executed in both RUN mode and PROGRAM mode.
• The user program is executed only in RUN mode.
Periodic tasks
Event tasks Event tasks are executed only in RUN mode.
The Processing Performed in Each Task
*1: Task period The CPU Unit executes tasks in this fixed period. This is a preset, fixed time.
*2: Task execution time This is the actual time it takes from the point that the execution condition is
met until execution is completed.
Processing Processing contents
I/O refresh-
ing
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 process-
ing 1
• Processing for exclusive control of variables in tasks (when accessing tasks are
set)
• Motion input processing is performed.
*1
• Data trace processing (sampling and trigger checking) is performed.
• Event task condition expressions are judged.
User program
execution
Refreshing
Output data
processing
System
common
processing 2
Motion control
System
common
processing 1
Input data
processing
Control processing
I/O refreshing
Task period
*1
= Primary period (fixed)
Task execution time
*2
(varies)

Omron NJ Series Specifications

General

Program Capacity	Up to 128 MB
SD Card Slot	Yes
Power Supply Voltage	24 VDC
Motion Control	Yes
USB Ports	1
Operating Temperature	0°C to 55°C
Communication Interfaces	Ethernet/IP, EtherCAT, USB
Safety Function	Optional
Storage Temperature	-20°C to 75°C
Communication Ports	USB
Dimensions	Varies by model
Weight	Varies by model