What is the difference between DeviceNet and EtherNet/IP?

DeviceNet is built over a CAN (Controller Area Networking) with bit-wise arbitration, devices transmit their messages concurrently, unlike most technologies where one node transmits and others are waiting their turn. Every device that concurrently transmits its bits can send the messages until it realizes a higher priority message is on the bus.

DeviceNet is perfect for applications where there is a linear node topology. It uses CIP, exactly like EtherNet/IP, but over a CAN physical layer.

There are a few advantages that CAN is providing to DeviceNet:

• 100% of the bus line utilization due to bit-wise arbitration
• DC Power over the network cables
• Simple and cost-effective components
• More adaptable to censors and actuators, with simplicity and ease of use

EtherNet/IP requires more powerful hardware and more sophisticated networks tasks. The speed is way higher but in the end, is almost always limited by the device's computing power (not the switch or wire speed).

One of the bigger problems or questions for DeviceNet is - will the vendors continue to provide support for it or only focus on protocols that operate on Ethernet standards? If this happens, all of the vendors will have to drop DeviceNet from use and focus on Ethernet components.

The other big problem that DeviceNet might face is the cost of the components - as fewer devices are made for an aging technology, the prices will go up. Ethernet is continually getting less expensive and industrial Ethernet is no longer different than the physical later in the commercial Ethernet networks.