Omron NJ Series

5 Designing Tasks
5-26
NJ-series CPU Unit Software User’s Manual (W501)
The processing for tag data links is separated in multiple processes. This processing is performed in
the tag data link service, the system services, and the tasks. The following example shows the process-
ing that is performed for the tag data links when the built-in EtherNet/IP port on the CPU Unit is used.
 Flow of Tag Data Reception Processing
• The tag data link service reads the tag data from the received tag sets.
• If a refreshing task is set, the task writes the values of the tag data to the variables that are
assigned to the tags.
• If a refreshing task is not set, a system service writes the values of the tag data to the variables
that are assigned to the tags.
 Flow of Tag Data Transmission Processing
• If a refreshing task is set, the task reads the values of the tag data from the variables that are
assigned to the tags.
• If a refreshing task is not set, a system service reads the values of the tag data from the variables
that are assigned to the tags.
• Then, in the tag data link service, the tag set is created from the tag data and the tag set is sent.
5-2-8 Processing Performed in and Execution Timing of the Tag Data
Link Service
Processing Performed in Tag Data Link Service
Received
tag set
Tag data
link service
Reads the
tag data.
Task set as
refreshing task
Tag data
Tag data
Refreshing task
is specified.
Refreshing task
is not specified.
Writes values
to variables.
System service
Writes values
to variables.
Tag set
is sent.
Tag data
link service
Creates the
tag set.
Tag data
Tag data
Refreshing task
is specified.
Refreshing task
is not specified.
Reads values
from variables.
System service
Reads values
from variables.
Task set as
refreshing task