Task period: 10 ms
Example: Primary periodic task
To Controller #2
To Controller #2
Refreshing period
during RPI
10 ms
I/O refreshing
User program execution
Motion control
Send data
processing
Send data
processing
Task period × 2
Time required to transfer data from Controller #1: 2
0 ms
Task period: 10 ms
E
xample: Primary periodic task
RPI of 10 ms
R
PI of 20 ms
Task period × 2
(
1)
(2)
(1) (2)
Refreshing period
during RPI:
20 ms
Transmission
path
Transmission
path
Controller#1
Controller#1
Data link processing
(system common processing 3)
OI MC
UPG
OI
UPG
MC
Tag data link service
Tag data link service
OI MC
UPG
OI MC
UPG
OI MC
UPG
OI MC
UPG
OI MC
UPG
OI MC
UPG
OI MC
UPG
15-3-4
Maximum Tag Data Link I/O Response Time
You can calculate the maximum I/O response time by adding up the time of (1) to (6) in the following
figure.
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
15 Communications Performance and Communications Load
15-26
NJ/NX-series CPU Unit Built-in EtherNet/IP Port User’s Manual (W506)