Developed by the US technology group Allen-Bradley, DeviceNet is one of the Fieldbus systems used in process automation. Together with ControlNet and EtherNet/IP, it forms a kind of protocol family. The common feature is that the Control and Information Protocol (CIP) is used as the application layer. On the lower layers, DeviceNet uses the specifications of the Controller Area Network (CAN) back, making it an inexpensive yet powerful technology. Its international standardization and dissemination are in the hands of the umbrella organization "Open DeviceNet Vendor Association" (ODVA). Communication in DeviceNet is subject to the publisher-subscriber model, which means that all bus participants in the network can be sender and receiver with equal rights. There is no clear distribution of roles based on the master-slave principle, as is known from PROFIBUS, for example, in DeviceNet.
The exchange of information occurs via two lines, CAN-L and CAN H, whereby the participants are switched in classic bus topologies. Since the available address range is from 0 to 63, the number of participants is limited to 64. However, the installation of repeaters makes it possible to segment a DeviceNet and thus create more complex structures.
DeviceNet analysis & diagnostic devices
Extensive measurement technology is no longer required to analyze the physical and logical quality of a DeviceNet. The compact CANBUSviewXL III diagnostic device is sufficient. It plugs into the measuring point via an adapter and thus integrates into the network without any reaction. The measuring points should be at the two ends of the segment. Here CANBUSview XL III can carry out a wiring test in offline mode and a signal test in online mode. The corresponding INspektor®, together with the network management software PROmanage® NT, is suitable for permanently monitoring CAN-based communication networks. They also allow for central network maintenance because this keeps the data of the installed INspektors together.