Ethernet

Ethernet is a family of networking technologies used for local area networks (LANs), characterized by its protocols, standards, and hardware. Invented by Robert Metcalfe and his colleagues at Xerox PARC in 1973, Ethernet began as a method to connect multiple computers within a single building or campus using coaxial cables.

Early Ethernet, standardized as IEEE 802.3 in 1983, provided speeds of 10 Mbps. Over time, it evolved to support faster data rates. In the 1990s, Fast Ethernet offered 100 Mbps, followed by Gigabit Ethernet with speeds of 1 Gbps, enhancing the capacity and performance of networked systems.

The 2000s introduced even higher speeds, with 10 Gigabit Ethernet becoming essential for data centers and high-performance applications. The most recent advancements include 25, 40, and 100 Gigabit Ethernet, catering to the growing demands for bandwidth and speed in cloud computing and data-intensive environments.

Today, Ethernet continues to evolve with the development of 400 Gigabit and Terabit-class Ethernet standards. Additionally, features like Power over Ethernet (PoE) allow devices to receive power and data over the same cable, simplifying network infrastructure.

Ethernet's scalability, reliability, and continual enhancement make it a cornerstone of modern networking, from small LANs to sprawling data center architectures.

The history of Ethernet in industrial communication dates back to the early 1980s and marks a significant evolution from its initial use in office environments and academic institutions to a cornerstone of industrial automation technology. It began to be experimented with in the manufacturing and process industries for data collection and supervisory control applications. Despite these early attempts, traditional industrial communication technologies such as serial communication protocols and fieldbus technologies like PROFIBUS remained dominant due to their proven reliability and determinism.

However, classic standard Ethernet is not suitable for industrial use as it does not offer deterministic communication, robustness, real-time capability and fault tolerance. Industrial environments require precise, predictable data transmission, resilience to harsh conditions and redundancy for continuous operation. Standard Ethernet could not meet these stringent requirements, which led to the development of specialized industrial Ethernet communication protocols such as PROFINET and EtherCAT in the 1990s. These protocols, released in the early 2000s, offer deterministic communication, enhanced environmental resilience, real-time data handling and built-in redundancy, ensuring reliable and efficient performance in demanding industrial applications.

The early 2000s witnessed an accelerated adoption of industrial Ethernet as the technology matured and gained acceptance within industrial circles. The introduction of gigabit Ethernet technologies provided higher data rates and greater bandwidth for demanding industrial applications. Industrial Ethernet switches, routers, gateways, and other network infrastructure components specifically designed for harsh industrial environments facilitated the deployment of Ethernet in industrial settings.

In recent years, Ethernet has become the de facto standard for industrial communication, powering critical infrastructure such as PLCs, HMIs, DCS, and SCADA systems. Its compatibility with Industry 4.0 initiatives and its ability to seamlessly integrate with emerging technologies such as IoT, cloud computing, and edge computing have further solidified its position as a key enabler of digital transformation in industrial sectors. Today, Ethernet continues to evolve to meet the evolving demands of Industry 4.0, with advancements such as Time-Sensitive Networking (TSN) and Industrial IoT (IIoT) capabilities driving innovation and efficiency in industrial communication.

Ethernet operates across two distinct layers of the OSI model: the physical layer and the data link layer. The physical layer is tasked with converting data frames received from the Data-link layer into bits of 1's and 0's for transmission over the network, highlighting its pivotal role in the actual data transmission process. This layer is also crucial for defining the electrical and physical specifications that allow devices to communicate over a network. It encompasses aspects like the layout of pins, voltages, cable specifications, and more, ensuring that data can be physically transmitted between devices.

Furthermore, at the Data Link Layer of the OSI model, Ethernet is responsible for the framing of data packets, error detection, and the management of physical addressing through Media Access Control (MAC) addresses. The Data Link Layer itself is divided into two sublayers: the Logical Link Control (LLC) and the Media Access Control (MAC) sublayers, each playing a distinct role in facilitating communication over the network. The LLC sublayer acts as an interface between the network layer above and the MAC sublayer below, handling error control, flow control, and frame synchronization. It encapsulates the network protocol data, which means that it adds control information to ensure proper communication between devices on the network. However, the MAC sublayer manages protocol access to the physical network medium. This includes controlling how devices on the network gain access to data and permission to transmit it. The MAC sublayer uses MAC addresses to ensure that data packets reach their intended destination on a local network segment.

Ethernet protocols offer two primary communication models that are prevalent: the Controller-Device model and Peer-to-Peer models. These models serve as the backbone for facilitating efficient and reliable data exchange within various industrial networks, including those utilizing Modbus TCP and EtherNet/IP protocols. Ethernet's support for a wide range of network topologies – including Star, Ring, Mesh, and Hybrid – underscores its adaptability and suitability for industrial communication. This versatility ensures that Ethernet can cater to the specific needs of diverse industrial applications, from simple setups to complex, interconnected networks.

Ethernet technology has branched out into several specialized variants, each tailored to meet the unique demands of industrial environments, as follows:

• Ethernet/IP
• PROFINET
• Modbus TCP
• Ethernet POWERLINK
• EtherCAT
• CC-Link IE

Ethernet offers several advantages for industrial communication, making it a preferred choice for connecting devices and systems in industrial automation and control environments:

• Interoperability

  Based on globally recognized standards, Ethernet ensures interoperability and compatibility among diverse devices and systems from various manufacturers. This standardization streamlines the integration and deployment of industrial Ethernet networks, mitigating the complexities and expenses associated with proprietary communication solutions.

• Flexibility

  Ethernet's support for various network topologies—including star, ring, and tree configurations—offers unparalleled flexibility in designing networks tailored to specific industrial applications and requirements. Protocols such as PROFINET and Ethernet/IP further contribute to this flexibility, accommodating a wide range of data types, communication modes, and network architectures to meet the diverse needs of industrial use cases

• Reliability

  Industrial Ethernet components are engineered to withstand the rigors of harsh environments, ensuring the durability and continuous operation required for mission-critical applications. Features like ring topologies, dual power supplies, and device-level redundancy bolster network reliability and fault tolerance, minimizing downtime and safeguarding against operational disruptions.

• Security

  Ethernet networks address these challenges through advanced security features such as VLANs, access control lists (ACLs), encryption, and authentication mechanisms. These measures fortify industrial networks, protecting the confidentiality, integrity, and availability of sensitive data and systems.

• Cost-effectiveness

  The widespread availability and affordability of Ethernet hardware components—such as switches, routers, and cables—make it a financially viable option compared to proprietary industrial communication technologies.

Industrial Ethernet is rapidly gaining traction across all industrial sectors, and it is poised to increasingly replace traditional fieldbuses due to its superior performance, scalability, and flexibility. Unlike traditional fieldbuses, which often rely on proprietary protocols and have limited data rates, Industrial Ethernet leverages communication protocols, enabling significantly higher data transfer speeds and extended network reach. This standardization leads to enhanced interoperability among devices from different manufacturers and supports seamless integration within complex automated systems. Furthermore, Industrial Ethernet provides robust real-time communication, crucial for time-sensitive industrial processes, and it can easily accommodate expanding network requirements as industries grow and evolve. Its ability to support a wide range of industrial applications while maintaining high reliability and low latency makes Industrial Ethernet the preferred choice for modern industrial automation and control systems.

The growing influence of the Industrial Internet of Things (IIoT) further underscores the importance of IP-based industrial communication. As more devices become interconnected through IIoT, the demand for efficient and scalable communication networks capable of handling vast amounts of data is escalating. Industrial Ethernet, with its IP-based infrastructure, meets these demands by enabling seamless data exchange and real-time monitoring across diverse devices, from sensors to high-end processing units. The adoption of IP-based communication facilitates remote access, predictive maintenance, and advanced analytics, driving operational efficiency and innovation. As industries continue to embrace the digital transformation driven by IIoT, the reliance on IP-based Industrial Ethernet will only intensify, solidifying its role as the backbone of modern industrial communication and paving the way for intelligent, interconnected industrial ecosystems.

Hilscher offers a wide range of products for industrial communication in Industrial Ethernet networks. The netX technology and the multiprotocol-capable SoCs (System on Chips) based on it are at the forefront. These can be integrated into industrial components - such as controllers, sensors or actuators - as highly integrated communication interfaces. Thanks to the associated firmware, which can be loaded onto the chip as required for the required protocol stack, Hilscher supports component manufacturers and automation specialists in the development of flexible solutions for use in a wide variety of Industrial Ethernet networks – for example for PROFINET, EtherCAT, EtherNet/IP, CC-Link IE or Ethernet POWERLINK.

Based on the netX communication controllers, Hilscher developed different embedded modules and the PC and fieldbus cards of the cifX family (which are available in all common form factors - from PCI and PCIe to the smallest multiprotocol-capable PC cards on the automation market in M.2 format). These communication interfaces already include the necessary chip peripherals and are therefore faster to integrate.

In addition, gateways, switches and network and communication diagnostic devices support the smooth operation of fieldbus networks.

Next to conventional Industrial Ethernet systems, Hilscher's components for industrial communication networks also support the most common fieldbus protocols - such as PROFIBUS, Modbus, CC-Link or DeviceNet.

The portfolio is rounded off by the netFIELD ecosystem for Managed Industrial IoT. From the edge gateway to the cloud platform for centralized container management, netFIELD offers everything you need to develop modern applications in line with Industry 4.0.