Terms And Definitions - Omron CK5M Series Connection Manual

Terms and Definitions

Terms
Node Controllers and devices are connected to an EtherNet/IP network through EtherNet/IP ports.
EtherNet/IP recognizes each EtherNet/IP port connected to the network as a node.
This means that a connected device that has two EtherNet/IP ports is recognized as two nodes.
EtherNet/IP achieves communications between Controllers, or communications between a Con-
troller and devices, through data exchange between the nodes connected to the network.
Tag The minimum unit of data that can be exchanged over an EtherNet/IP network is called tag. A tag
is defined as a network variable name or physical address and allocated to the memory area of
each device.
Tag set In an EtherNet/IP network, data can be exchanged in a data unit that is composed of two or more
tags. A data unit that is composed of two or more tags for the purpose of data exchange is called
tag set.
Tag data EtherNet/IP supports cyclic exchange of tags and tag sets between nodes without the need for a
link user program. This function is called tag data link.
Connec- The unit of data exchange is called connection. A connection is composed of tags and tag sets.
tion Opening a synchronous tag data link between specified nodes is called "establishing a connec-
tion." Once a connection is established, the tags and tag sets that compose the connection are
exchanged synchronously between specified nodes.
Connec- There are two connection types for tag data link connections. They are multicast connection and
tion type unicast (point-to-point) connection. Multicast sends a single output tag set in a packet to multiple
nodes. On the other hand, unicast sends a single output tag set to each node individually. This
means that multicast allows a single output tag set to be sent to multiple nodes with less communi-
cations load.
Originator To perform tag data link communications, one node makes a request to open a communications
and target line called "connection."
The node that requests to open a connection is called "originator", whereas the node that is re-
quested to open a connection is called "target". The data that is communicated by these nodes is
called "originator variables" and "target variables", respectively.
Tag data In tag data link settings, tag data link parameters refer to a set of setting data that consists of "tag
link pa- settings", "tag set settings", and "connection settings".
rameters
RPI An abbreviation for Requested Packet Interval. Represents a data refresh period set for each con-
nection between originators and targets on an EtherNet/IP network.
EDS file EDS (Electric Data Sheet) is a text-based file that provides device-related information to a pro-
gramming software.
You can use EDS files provided by EtherNet/IP device manufacturers to easily configure connec-
tions.
Power This is computer software that is used to configure the PMAC, create user programs, and perform
PMAC IDE monitoring.
PMAC is an abbreviation for Programmable Multi-Axis Controller.
CK3E/CK3M/CK5M Series EtherNet/IP Connection Guide (O903)
Descriptions and Definitions
Terms and Definitions
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