DeviceNet – designed for factory automation

DeviceNet, trademarked by ODVA, is mainly used in factory automation as a communication network between controllers (e.g. PLCs) and industrial I/O devices (e.g. limit switches, sensors, drives, displays, and operator interfaces) as well as electrical drives and human machine interfaces (HMI). It is based on the Classical CAN data link layer. Therefore, it is a producer-consumer network approach that supports multiple communication hierarchies and message prioritization. DeviceNet supports master/slave as well as peer-to-peer communication. DeviceNet is internationally standardized in IEC 62026-3.

Devices are distributed along a DeviceNet network in a trunk-line/drop-line topology. Up to 64 nodes may be connected to a single network segment. This means that a CAN high-speed transceiver compliant to ISO 11898-2 needs to drive up to 64 modules. DeviceNet supports arbitration bit-rates of 125 kbit/s at 500 m, 250 kbit/s at 250 m, and 500 kbit/s at 100 m for the thick trunk cable. DeviceNet specifies the cables (thick trunk, thin trunk, and flat trunk cable) and connectors (e.g. mini-style, micro-style). Some cables may supply device power along the same cable as the communication cable.

The DeviceNet data link layer complies with ISO 11898-1. However, only the Classical CAN protocol is allowed and CAN remote frames must not be used.

On the upper layers (OSI layer 5 to 7), DeviceNet uses the Common Industrial Protocol (CIP), which is specified by the ODVA. CIP is also used by other network technologies supported by ODVA. CIP-based networks provide connectivity in heterogeneous communication systems.

ODVA – the user association

Allen-Bradley (now owned by Rockwell Automation) originally developed DeviceNet, which is layered on top of the CAN (Controller Area Network) protocol. In order to promote the use of DeviceNet worldwide, Rockwell Automation adopted the "open" concept and decided to share the technology with third party vendors. Hence, it has been managed by the ODVA since 1995, a global organization located in North America. ODVA maintains the DeviceNet specifications and supports the internal standardization in IEC. In addition, ODVA ensures compliance to the DeviceNet standards by providing a conformance testing service. Conformance testing is obligatory.