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10. Appendix D: DeviceNet Objects
10.1. Introduction to the Gateway’s DeviceNet Objects
The LUFP9 gateway’s software has been developed in accordance with the Object Modelling from the
DeviceNet protocol. This model leads to a method used for addressing the gateway’s data, known as
Attributes,
made up of four separate values:
c the node address (MAC ID), d the Object’s class identifier (Class ID), e the
Instance Number (Instance ID) and f the Attribute Number (Attribute ID). An address made up in this way is
known as a “
Path”. The Connection by Explicit Messaging, for example, uses paths of this sort to exchange data
from one point to another on a DeviceNet network.
Address Min. – max. Description
Node 0 – 00 063
This field allows you to address one subscriber out of the series of subscribers on a
DeviceNet network using its MAC ID.
Class 1 – 65 535
All objects sharing the same characteristics belong to the same class, characterized by its
Class ID.
Instance 0 – 65 535
The instances represent the various objects from one class. All instances from one class
share the same behaviours (1) and the same attributes, but each of them has its own set of
values for these attributes. When a subscriber creates an instance (instantiation), he assigns
a unique Instance ID, which allows the other DeviceNet subscribers to have individual
access to it.
Attribute 1 – 00 255
Each attribute represents one of the characteristics of the Instances belonging to the same
class. It is assigned some sort of value (byte, unsigned integer, character string, etc.) in
order to supply information about the subscriber’s status or to make settings on the
subscriber’s behaviours (1).
N.B. To access the attributes of an object’s base class, you need to use Instance 16#00
when entering the full path. e.g. To access the “Revision” attribute from the “Identity Object”
class for DeviceNet subscriber no. 4, you will need to use the following path:
“16#04 • 16#01 • 16#00 • 16#01”.
(1) The behaviours designate actions taken by a DeviceNet object in response to particular events.
10.2. List of the Gateway’s DeviceNet Objects
Class ID
Required
Instances Interfaces
Identity object 16#01 Yes 1 Message router
Message router 16#02 Yes 1 Explicit message connection
DeviceNet object 16#03 Yes 1 Message router
Assembly object 16#04 No 2 (1) I/O connections or Message router
Connection object 16#05 Yes 4 (2) I/O connections or Explicit messages
Acknowledge handler object 16#2B No 1 I/O connections or Message router
I/O data input mapping object 16#A0 No 1 Message router
I/O data output mapping object 16#A1 No 1 Message router
Diagnostic object 16#AA No 1 Message router
(1) One input area and one output area are created in the gateway’s memory.
(2) The four instantiated connections are as follows:
c Explicit Connection, d Polled Command/Response,
e Bit Strobed Command/Response and f Change-of-State / Cyclic. The last three connections are of the
“I/O Connection” type.