The
Device Level Network
DeviceNet was originally developed by Rockwell
Automation and today, It is managed by the Open
Devicenet User organization (ODVA). Devicenet
is among the worlds leading device level networks
for industrial automation. DeviceNet is
a very popular network for time critical applications
based on Rockwell Automation technology. DeviceNet
offers robust, efficient data handling because
it is based on Producer/Consumer model. DeviceNet
is standardized in the international standard
series IEC 61158. DeviceNet devices are certified
for interoperability and conformance to the DeviceNet
standard by ODVA.
Provider/Consumer Communication
DeviceNet is a digital,
multi-drop network that connects and serves as
a communication network between industrial controllers
and I/O devices. Each device and/or controller
is a node on the network. DeviceNet is a producer-consumer
network that supports multiple communication
hierarchies and message prioritization. DeviceNet
systems can be configured to operate in a master-slave
or a distributed control architecture using peer-to-peer
communication. DeviceNet systems offer a single
point of connection for configuration and control
by supporting both I/O and explicit messaging.
DeviceNet also has the unique feature of having
power on the network. This allows devices with
limited power requirements to be powered directly
from the network, reducing connection points
and physical size.
DeviceNet uses a trunk-line/drop-line
topology that provides separate wire pairs
for both signal and power distribution.
Thick or thin cable can be used for either trunklines
or droplines. End-to-end network length varies
with data rate and cable thickness.
DeviceNet uses the Common Industrial
Protocol, called CIP, for its upper protocol
layers. CIP is strictly object oriented. Each
object has attributes (data) and services (commands)
and behavior (reaction to events). Two different
types of objects are defined in the CIP specification:
communication objects and application-specific
objects. Vendor-specific objects can also be
defined by product vendors for situations
where a product requires functionality that is
not in the specification.
Configuration with EDS-Files
During the setup phase of the DeviceNet network, the DeviceNet
Master Scanner must be configured with a special configuration tool such as Rockwell's
RSNetWorx or HMS´s NetTool. The configuration process is based on electronic
device data sheets (EDS-Files) which are required for each DeviceNet
device. EDS-Files are provided by the device manufacturers and contain electronic
descriptions all relevant communication parameter and objects of the DeviceNet
device.
HMS is an active member of the DeviceNet User Organization
and participates actively in the further standardization
of the DeviceNet technology. HMS offers a broad
range of certified DeviceNet products.
See
Anybus products supporting the DeviceNet network