2 ． Terms and Definitions 2. Terms and Definitions 2 Term Explanation and Definition Node 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. Tag 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. Tag set 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. Tag data link 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. Connection 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. Originator and Target 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 an "originator", and the node that receives the request is called a "target". Tag data link parameter 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. EDS file A file that describes the number of I/O points for the EtherNet/IP device and the parameters that can be set via EtherNet/IP.