14 Communications Performance and Communications Load
14-26
NJ/NX-series CPU Unit Built-in EtherNet/IP Port User’s Manual (W506)
You can find the maximum I/O response time from the total of (1) to (6) in the following figure.
• With unit version 1.03 or later, processing for tag data links is executed in the tag data link ser-
vice.
• With unit version 1.00 to 1.02, processing for tag data links is executed in the system services.
If a tag data link timeout occurs, reconsider the execution time for system services.
(1) Input ON Response Time
This is the delay time for the external input device from when the input occurs until the switch actu-
ally changes to ON and the time until the input data is stored in the memory area of the CPU Unit.
Refer to the input delay of each device for the input switch delay time. Also, one task period is
required until the data is stored in the memory area of the CPU Unit. Therefore, the input ON
response time is obtained as shown below.
Input ON response time = Input device delay time + Task period
14-3-4 Maximum Tag Data Link I/O Response Time
Example of data transfer processing over 3 task periods
(1)
(2)
(3)
Output
device
Input device
Transmission
path
Task period
Controller #2
processing
Tag data link
refresh period
Task period
Input
(4) Network transmission delay time
(1) Input ON
response time
(6) Output ON
response time
(5) Receive Data
Processing Time
(2) Send data
processing time
Data link processing (system
common processing 2)
Motion control
User program execution
I/O refreshing
Tag data link I/O response time
(3) RPI
Controller
#1
Controller
#2
Output
Example: Primary periodic task
Tag data link service
OI UP
G
MCOI UP
G
MCOI UP
G
MCOI UP
G
MC
OI UP
G
MC OI UP
G
MC OI UP
G
MC OI UP
G
MC OI UP
G
MC
MC
OI
UPG
OI UP
G
MC
Controller #1 processing
Tag data link service