Omron SYSMAC CJ1W-EIP21 - Manual (Page 407)

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Appendix D
CIP Message Communications
This appendix describes CIP message communications.
The basic concepts of CIP message communications are described in this appendix from CIP Object on
page 381 through Example of CIP Message Creation on page 386. Read these sections to improve your
understanding of CIP message communications.
CIP Object
Object Model
In the CIP (Common Industrial Protocol) system, each device is modeled as a group of “Objects.” An Object
abstractly represents a related group of the device’s data values.
When accessing the device from the outside, access an Object.
An Object represents the abstracted device function, processing, and the resulting data.
A request from the outside of Object, such as Read Data, is called “Service.”
Data belonging to the Object is called “Attribute.”
The actual entity of Object is called “Instance” or “Object Instance.”
When Object is generalized, it is called “Class.” For example, “Japan” is one of Instances (Object Instances) of
Class “Nation.”
Object
Object
Object
Device
Service Data
Processing
Object Instance
Attribute
External request
(Example. Read, Write)
Data
Data
Data