Owner's manual

Publication 2098-RM001C-EN-P – August 2002
2-4 Programming Reference
Object Addressing
The Media Access Control Identifier (MAC ID) is the common basis for
logically addressing separate physical components across DeviceNet.
The MAC ID is a unique integer assigned to each DeviceNet node that
distinguishes it specifically from among other nodes on the same
network. The MAC ID often is referred to as the node address. Each
MAC ID is further identified with the following address components:
Figure 2.2
Node Objects
Component Description
Class ID The Class ID is a unique integer value assigned to each Object Class
accessible from the network. The Ultra3000 supports an 8-bit Class ID.
Instance ID The Instance ID is a unique identification assigned to an Object Instance
that identifies it among all Instances of the same Class.
It is also possible to address the Class itself by utilizing the Instance ID
value zero (0). The Ultra3000 supports an 16-bit Instance ID.
Attribute ID The Attribute ID is a unique identification assigned to a Class Attribute
and/or Instance Attribute.
MACID#1 MACID#2
Instance
Object
MACID#4
MACID#3
DeviceNet Network
Class #5
#1
Instance
Object
Class #3
#1
Instance
#2
Object
Class #5
Instance
#1
Attribute #1
Attribute #2
MACID#4:
Object Class #5
Instance #2
Attribute #1
DeviceNet Node 1 DeviceNet Node 2
DeviceNet Node 3 DeviceNet Node 4