Terms And Definitions - Omron CJ2 Series Network Connection Manual

2. Terms and Definitions

Term
Node
Tag
Tag set
Tag data link
Connection
Originator and
Target
Tag data link
parameter
Explanation and Definition
Controllers and devices are connected to the EtherNet/IP network via the
EtherNet/IP ports. The EtherNet/IP recognizes each EtherNet/IP port
connected to the network as one node.
When a device with two EtherNet/IP ports is connected to the
EtherNet/IP network, the EtherNet/IP recognizes this device as two
nodes.
The EtherNet/IP achieves the communications between controllers or the
communications between controllers and devices by exchanging data
between these nodes connected to the network.
A minimum unit of the data that is exchanged on the EtherNet/IP network
is called a tag. The tag is defined as a network variable or as a physical
address, and it is allocated to the memory area of each device.
In the EtherNet/IP network, a data unit that consists of two or more tags
can be exchanged. The data unit consisting of two or more tags for the
data exchange is called a tag set. Up to eight tags can be configured per
tag set for OMRON controllers.
In the EtherNet/IP, the tag and tag set can be exchanged cyclically
between nodes without using the user program. This standard feature on
the EtherNet/IP is called a tag data link.
A connection is used to exchange data as a unit within which data
concurrency is maintained. The connection consists of tags or tag sets.
Creating the concurrent tag data link between the specified nodes is
called a "connection establishment ". When the connection is
established, the tags or tag sets that configure the connection are
exchanged between the specified nodes concurrently.
To perform tag data links, one node requests the opening of a
communications line called a "connection".
The node that requests opening the connection is called "originator", and
the node that receives the request is called a "target".
The tag data link parameter is the setting data to perform the tag data
link. It includes the data to set tags, tag sets, and connections.
2. Terms and Definitions
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