Built on the standard TCP/IP protocols, it utilizes long established Ethernet hardware and software to define an application layer protocol for configuring, accessing and controlling industrial automation devices.
EtherNet/IP classifies Ethernet nodes as predefined device types with specific behaviors. This allows for:
1.) Transfer of basic I/O data via UDP. For example: digital or analog I/O. (Implicit messaging)
2.) Uploading and downloading of parameters, setpoints, programs and recipes via TCP. (Explicit messaging)
3.) Polled, Cyclic and Change-of-State via UDP. For example RPI and COS in Allen Bradley's ControlLogix system.
4.) One-to-one(unicast), one-to-many(multicast), and one-to-all(broadcast) via TCP.
The EtherNet/IP application layer protocol is based on the Common Industrial Protocol (CIP) layer used in both DeviceNet, CompoNet and ControlNet. Building on these protocols, Ethernet/IP provides a seam-less integrated system from the Industrial floor to the enterprise network. An overview of the EtherNet/IP technology can be found here:
ODVA is the organization that supports network technologies built on the Common Industrial Protocol (CIP). These currently include the network adaptations of CIP—EtherNet/IP, DeviceNet and CompoNet—and major application extensions to CIP: CIP Safety, CIP Motion and CIP Sync. More information on the CIP technologies and standardization can be found here:
Subsequently, additional CIP profiles have been developed that also operate with EtherNet/IP, these include CIP Safety, CIP Sync (this embodies IEEE 1588) and CIP Motion.
EtherNet/IP was intended to be opened to the public, and at once it was suggested to publish the Level 2 source codes in sourceforge.net, but failed. Although freeware source code can now be downloaded from the ODVA's website at (registration required to access download)