What Is EtherNet/IP: A Comprehensive Guide

EtherNet/IP is a widely used industrial Ethernet standard that allows devices to communicate over an Ethernet network. This comprehensive guide will provide you with a deep understanding of EtherNet/IP, its technical aspects, benefits, and how to implement it in your network.

Understanding the Basics of Ethernet/IP

EtherNet/IP is an open industrial network protocol that uses Ethernet communication as a backbone for industrial automation applications. It enables devices from different manufacturers to easily communicate with each other - namely, programmable logic controllers (PLCs) and other automation equipment.

It primarily adopts the CIP protocol (Common Industrial Protocol) to standard Ethernet, allowing users to be able to utilize Ethernet in their industrial networks. A widely used protocol, it is estimated to have about 30% of the industrial ethernet market today, and is particularly popular in the United States.

The History and Evolution of Ethernet/IP

In the 1990s, the ControlNet International organization started the development of EtherNet/IP. They and the ODVA (a global standards development organization and membership association) formed a JTA (joint technology agreement) for EtherNet/IP at the turn of the 21st century - in 2009, the protocol become one of the standards in the ODVA protocol portfolio that the organization oversees.

How Ethernet/IP Works

EtherNet/IP uses a client-server architecture that allows devices, such as programmable logic controllers (PLCs) and other industrial devices, to exchange data over an Ethernet network. This client-server model ensures efficient and reliable communication between devices.

EtherNet/IP follows the OSI model (Open Systems Interconnection), commonly used for network communication. For the upper layers of the OSI model (levels 5, 6 & 7), EtherNet/IP uses the CIP protocol, which provides a consistent framework for data exchange between devices. CIP defines a set of rules and conventions that devices must follow to communicate effectively. It ensures that devices can understand each other's messages and interpret the data being exchanged - this occurs due to CIP having an object oriented design.

EtherNet/IP combines CIP with the most common Ethernet standards - such as the Internet Protocol suite and IEEE 802.3, mainly for the protocols' transport, network, data link and physical layers. Additionally, it leverages the UDP protocol (User Datagram Protocol) for transporting I/O messages.

The Technical Aspects of Ethernet/IP

In this section we dive deeper into some of the features and some of the core underlying technical details behind EtherNet/IP.

Key Features of Ethernet/IP

EtherNet/IP boasts several key features that make it a popular choice for industrial applications. One of its standout features is high-speed data transfer. With EtherNet/IP, data can be transmitted at incredibly fast speeds, ensuring efficient communication between devices.

Real-time performance is another important feature of EtherNet/IP. It allows for the immediate exchange of data, enabling real-time control and monitoring of industrial processes. This is crucial in industries where timing is critical, such as manufacturing or robotics.

Another advantage of EtherNet/IP is its multicast support. This means that a single message can be sent to multiple devices simultaneously, reducing network traffic and improving efficiency. Multicast support is particularly useful in scenarios where data needs to be distributed to multiple recipients, such as in a factory setting.

EtherNet/IP supports a wide range of data types, including simple data types like integers and floats, as well as more complex data structures. This flexibility allows devices to exchange different types of data, enabling them to work together seamlessly.

In addition to data exchange, EtherNet/IP also provides mechanisms for device discovery, configuration, and diagnostics. These features make it easier for devices to join the network, configure their settings, and troubleshoot any issues that may arise.

EtherNet/IP has two types of network connections: explicit and implicit. As EtherNet/IP uses TCP/IP, it supports the ability to manage client-server types of transactions between devices or nodes (which can be any IP address) - this is known as explicit messaging.

Equally, EtherNet/IP also supports TCP/UDP, which enables real-time messaging by being able to multicast (messaging a number of destination/host addresses). UDP is connectionless (and smaller in size compared to TCP), and since the data is pre-defined at the time the connection is established, processing is reduced at runtime. This is ideal for implicit messaging, where EtherNet/IP uses UDP to transfer real-time I/O data rapidly, critical for manufacturing & control operations. The use of UDP also allows the protocol to support polled, cyclic and change-of-state monitoring for more flexible data transmission options.

Ethernet/IP vs. Traditional Ethernet

While Ethernet/IP is based on traditional Ethernet technology, there are some key differences between the two. Ethernet/IP adds industrial-specific functionality to Ethernet, allowing it to meet the unique requirements of industrial automation.

Traditional Ethernet is primarily designed for general-purpose networking and communication. It is widely used in office environments and home networks. However, it may not provide the necessary features and performance required in industrial settings.

Ethernet/IP, on the other hand, is specifically tailored for industrial applications. It incorporates features such as real-time performance, multicast support, and integration with other protocols to meet the demands of industrial automation. These enhancements make Ethernet/IP a reliable and efficient choice for industries that rely on precise and timely communication between devices.

In conclusion, Ethernet/IP offers a range of key features that make it a popular choice for industrial applications. Its high-speed data transfer, real-time performance, multicast support, and seamless integration with other Ethernet-based protocols make it an ideal communication protocol for industries that require reliable and efficient communication between devices.