Classes, Instances and Attributes
Classes, Instances and Attributes
The CIP object model uses classes, instances and attributes to describe each device. Refer to
the following figure.
l
Class: a fixed collection of objects with each object having a fixed set of attributes. The
CIP object library contains three primary object classes: general use, application spe-
cific, and network specific.
l
Instance: an occurrence of a particular object (in other words, there can be more than
one occurrence of the same object but with different attribute values).
l
Attributes: a set of data values that describe an object instance (instance attributes).
They can also describe an object class (class attributes).
Device Address
Object 2
Instance 1
Object Class 2
Object 1
Instance 2
Object Class 1
Attribute 3
Attribute 2
Attribute 1
Object 1
Instance 1
Attribute 3
Attribute 2
Attribute 1
Classes, Instances, Attributes
The device description (class, instance, attributes) information is also contained in the Elec-
tronic Data Sheet (EDS) file, which is supplied by the equipment vendor (see EDS File on page
35).
For more details, see the ODVA.org website.
Moog Animatics Class 6 EtherNet/IP Guide, Rev. B
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