7 Tag Data Link Functions
7-12
NY-series Industrial Panel PC / Industrial Box PC Built-in EtherNet/IP Port User’s Manual (W563)
To maintain the concurrency of data in a tag data link, you must set a refreshing task for each network
variable that is assigned to a tag.
•
Maintain concurrency in the tag data in a tag set.
•
The timing of updating network variables that are assigned to tags is synchronized with the execution
period of the program that accesses the network variables.
Additional Information
A refreshing task maintains concurrency of the value of a global variable from all tasks that
access that global variable. This is achieved by specifying a single task that can write to that
global variable and not allowing any other task to write to that global variable. For details on
refreshing tasks, refer to the
NY-series Industrial Panel PC / Industrial Box PC Software User’s
Manual
(Cat. No. W558).
Maintaining Concurrency in the Tag Data in a Tag Set
To maintain concurrency in the values of multiple tags in a tag set, the tags (variables with a Net-
work Publish attribute) must satisfy the following four conditions.
(1) The tags must be assigned to the same tag set (connection).
(2) A refreshing task must be set for the network variables assigned to the tags, and the
refreshing task must be the same for all tags in the tag set.*
(3) The variable access time set for each task must be set to a higher value than is
required to transfer the tag data. Refer to
13-3-3 Relationship between Task Periods
for details on the variable access time and data transfer.
* If you set a refreshing task for a network variable, you must set a variable access time to allocate
enough time to access the network variable from outside of the Controller.
•
Setting Refreshing Tasks for Tags (Network Variables)
Concurrency of the tags in the tag set is maintained.
7-1-7
Concurrency of Tag Data Link Data
NJ/NX-series Controller
NY-series Controller
Connection
Tag data links updated.
Refreshing task
Refreshing task
EtherNet/IP
10
10
10
Value of variable
100
10
100
10
100
10
Value of variable
Variable
c
Variable
b
Variable
a
Variable
c
Variable
b
Variable
a
Tag set
Variable
f
Variable
e
Variable
d
Tag set
The values of the
tags in the tag set
are refreshed at
the same time.
Summary of Contents for Sysmac NY512-1300
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