I/O Response Time In Tag Data Links; Timing Of Data Transmissions - Omron CJ1W-EIP21 Operation Manuals

12-3 I/O Response Time in Tag Data Links

Additional Information
This section provides information on the EtherNet/IP Unit. The data processing times for the
built-in EtherNet/IP ports on the NJ501-@@@@/NJ301-@@@@ NJ-series CPU Units,
CJ2HCPU6@- EIP CPU Units, and CJ2M-CPU3@ CPU Units are different. For details, refer to 7-
4 Tag Data Links with Models Other than NJ-Series CPU Units.

12-3-1 Timing of Data Transmissions

The following diagram shows the timing of tag data link transfers between the EtherNet/IP Unit and the
CPU Unit. Data is transferred during I/O refresh processing for the task that is set as the refreshing
task.
Data received.
Controller
Processing
You can set either of the following types of tasks as the refreshing task.
• Primary periodic task
The primary periodic task has the highest execution priority. It executes processes with high speed
and high precision.
• Periodic tasks
Periodic tasks are executed during the time between executions of the primary periodic task.
You do not need to specify a refreshing task for tags that use an AT specification. Data is transferred for
these tags during the primary periodic task. The task during which to perform tag data link processing is
specified for each tag. Set the refreshing task on the Sysmac Studio for each variable you want to set
as a tag. Refer to the Sysmac Studio Version 1 Operation Manual (Cat. No. W504) for details on setting
refreshing tasks.
CJ-series EtherNet/IP Units Operation Manual for NJ-series CPU Unit (W495)
12 Communications Performance and Communications Load
Primary periodic task
I/O refresh
Refreshing
System common
processing 1
Data exchange
processing
Controller task period
Control processing
Execution of
programs
Data exchange processing
12
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