VAT 653 AQ Series, Инструкции по установке, эксплуатации и обслуживанию

Страница: 62 / 110

INSTALLATION Series 65
62/110 Edition 2019-06-05 982156EB
4.9 DeviceNet

interface
4.9.1 Introduction
The following Object Modeling related terms are used when describing services and protocol:
Object – An abstract representation of a particular component within a product.
Class – A set of objects that all represent the same kind of system component. A class is a generalization of an
object. All objects in a class are identical in form and behavior, but may contain different attribute values.
Instance – A specific and real (physical) occurrence of an object. For example: New Zealand is an instance of the
object class Country. The terms Object, Instance, and Object Instance all refer to a specific Instance.
Attribute – A description of an externally visible characteristic or feature of an object. Typically, attributes provide
status information or govern the operation of an Object. For example: the ASCII name of an object; and the
repetition rate of a cyclic object.
Service – A function supported by an object and/or object class (set, get, reset,…)
Object Model Terminology Example:
Class Instance Attribute Attribute Values
Human Mary Gender Female
Age 31
Jerry Gender Male
Age 50