Advantages of Industrial Ethernet in industrial automation

Industrial Ethernet definition and more – explained in a nutshell

Different types of switches play a central role in modern Industrial Ethernet networks. According to the Industrial Ethernet definition, components such as an Industrial POE switch or industrial switch must be reliable, robust, and durable. Such an Industrial Ethernet switch must connect machines, sensors, PLCs, and other devices reliably and over a long period of time. A classic industrial Ethernet switch, for example, is specially designed for use in harsh industrial environments. It is also characterized by its ability to support different industrial Ethernet protocols such as PROFINET, EtherCAT, or EtherNet/IP.

Particularly important here is the ability to prioritize the transmission of time-critical data packets so that real-time Ethernet applications function reliably. Typical areas of application are manufacturing plants, production lines, or robot systems in which many devices must be networked and synchronized simultaneously.

A special subtype is the industrial PoE switch, which, in addition to data transmission, also supplies power via the same cables – i.e., supports Power over Ethernet (PoE). This allows cameras, sensors, or HMI panels to be powered directly without additional power lines. Industrial PoE switches are also designed for harsh environments and support prioritization and deterministic communication.

The term industrial switch is a general collective term for switches that have been specially developed for industrial Ethernet. In practice, industrial switches are often used as a synonym for industrial Ethernet switches, but can also refer to older or manufacturer-specific models. An industrial switch is characterized by its resilience, long service life, and high flexibility. They also support ring or line topologies to prevent network failures.

Overall, it is clear that industrial Ethernet switches, industrial PoE switches, and industrial switches form the central infrastructure of modern industrial Ethernet networks. They ensure that control systems, sensors, actuators, and IT systems communicate reliably with each other, processes run synchronously, and networks can be expanded flexibly.

Differences between conventional Ethernet and Industrial Ethernet

Conventional Ethernet in classic office or IT networks is based on IEEE 802.3 and is primarily designed for high bandwidth. Latencies play a rather minor role and lost packets can simply be resent. However, these characteristics are insufficient in industrial applications. Since control commands, sensor data, and actuator commands must be transmitted within precisely defined time windows, the requirements for latency-free transmission are much higher. This feature plays an important role, especially in synchronized robot axes, Ther-CAT PLC systems, or complex production lines.

Industrial Ethernet offers decisive advantages here:

Real-time Ethernet ensures deterministic data transmission, low latencies, and high reliability. On the hardware side, industrial-grade components such as industrial PHY, robust industrial Ethernet cables, RJ45 and IEC 63171-6 connectors, and industrial switches are used, which operate stably even under extreme environmental conditions. Standard Ethernet does not offer this.

Another distinguishing feature is the prioritization of data packets. Industrial switches enable VLANs, QoS, and the preferential transmission of time-critical data. This is crucial in drive technology, where delays can lead to production errors. Deterministic transmission guarantees the advantages of industrial Ethernet, such as short response times, high reliability, and stable communication.

In addition, industrial Ethernet allows hybrid and highly flexible network topologies to be set up. This means that line, star, and ring structures can be easily combined, creating redundant transmission paths for critical data packets. This also increases resilience to failures or external attacks and ensures that manufacturing processes can continue uninterrupted even if individual components fail or malfunction.

Industrial Ethernet protocols (Industrial Ethernet)

Industrial Ethernet and Industrial Ethernet protocols define the communication standards, cycle times, and synchronization mechanisms between devices and manufacturing components. They are at the heart of modern automation in industrial environments and are crucial for real-time Ethernet. We have listed the globally relevant representatives in the field of industrial Ethernet below

PROFINET (Industrial Ethernet Profinet) is the leading industrial Ethernet standard, particularly in Europe and Asia. PROFINET supports RT and IRT modes and enables deterministic communication between controllers, sensors, and actuators. PROFINET is therefore ideal for complex production lines and can also use different topologies. In addition to star and line topologies, PROFINET also supports ring topologies. The difference between the two modes is that RT is used in standard applications, while IRT is used for time-critical axes or motion control systems.

EtherCAT (EtherCAT PLC) is a highly deterministic protocol that enables cycle times of less than 100 microseconds and thus operates with virtually no latency. It is therefore preferred for use in drive technology and synchronized robot axes. EtherCAT transmits data while the data packets “flow” through the devices, which significantly minimizes latency. This allows, for example, several hundred axes to be controlled in real time and with virtually no delay.

EtherNet/IP is based on CIP and offers soft real-time performance. It is widely used internationally and is ideal for heterogeneous production lines that require IT integration. It offers flexibility and is well suited for production facilities that have a mix of standard PLCs and modern devices.

Modbus TCP is simple, interoperable, and cost-effective. It is often used in sensor and actuator controls. For smaller machines or older systems that do not require high cycle times, Modbus TCP is a solid choice.

SERCOS III and POWERLINK Ethernet are protocols designed for extremely deterministic communication—deterministic means that data packets in networks reach their respective destinations within a specified, predictable time frame (also known as latency). This is one of the main reasons why these protocols are often used in synchronized production lines and motion control systems. Cycle times are often in the microsecond range, and multiple axes can be controlled simultaneously.

BACnet IP and HART-IP are designed for building automation. BACnet/IP is primarily used for building automation, while HART-IP is used for process automation. They integrate air conditioning, lighting, security, and energy management systems into a network. These protocols also demonstrate the advantages of industrial Ethernet, as data can be transmitted reliably and with low latency.

OPC UA enables standardized communication between machines, controllers, and IT systems. It can be used across manufacturers and facilitates the integration of production data into analysis or cloud systems. In Industry 4.0 environments, OPC UA is the central building block for networking production and IT.

Physical Ethernet interfaces (industrial PHY)

The physical layer of an industrial Ethernet network is implemented using industrial PHY and industrial Ethernet cables. It forms the basis for industrial Ethernet advantages such as low latency, high reliability, and stable communication.

SPE (Single Pair Ethernet) enables data to be transmitted over a single pair of wires. This reduces cable installation and effort, saves costs, and also enables use in confined or difficult-to-access areas. SPE is ideal for sensor networks, field devices, and machine components that do not require high data rates but do require precise real-time Ethernet communication.

Important industrial Ethernet connector types

RJ45 is the standard connection for devices that do not require extreme environmental conditions. This connector type is also widely used by end customers in the private sector. Ethernet switches, PCs, WLAN routers, TV sets, and NAS devices usually have one or more connection sockets for RJ45 connectors.

IEC 63171-6 connectors are shielded and robust, making them suitable for IIoT (Industrial Internet of Things) and Industry 4.0. They are available in protection classes ranging from IP20 to IP6X. They are suitable for hazardous areas, e.g., with IP67.

M12 D/X: These connectors are robust, vibration-proof, waterproof, and are often used in industrial-grade systems.

Industrial PHY (Physical Layer Transceiver) is the physical layer or transmitter/receiver that transmits signals between devices. PHY ensures error correction, high signal quality, and stability even under extreme conditions. Together with industrial Ethernet cables and connectors, such a PHY module forms the basis for deterministic industrial Ethernet protocols and real-time Ethernet.

Which Ethernet variants for which applications?

As already mentioned in this guide, not every Ethernet variant is suitable for every task. While some applications primarily require a high data rate, others depend on short response times or maximum robustness. Accordingly, different Ethernet variants have become established in industry, depending on the sector and requirements. Classic Ethernet according to IEEE-802.3 usually forms the technological basis for all Ethernet Industrial solutions. Typical applications for this industrial Ethernet protocol are the connection of operator stations, industrial PCs, and visualization systems. Industrial Ethernet goes a big step further here. It specifically applies the Ethernet principle to the requirements of industrial environments. Not only do components such as robust switches, special cables, and durable connectors have to be suitable for industrial use so that Ethernet can function reliably even under harsh conditions. As already mentioned, industrial Ethernet PROFINET is one of the most commonly used industrial Ethernet protocols.

This industrial Ethernet protocol is ideal for classic automation tasks with programmable logic controllers. In automotive manufacturers' production lines, for example, PROFINET handles communication between the PLC (programmable logic controller), sensors for product detection, and actuators (e.g., valves, conveyor belts, motors in packaging machines). The cycle times of a PROFINET are short enough to control processes stably, while at the same time the network can be expanded flexibly. The situation is different, however, for applications that place particularly high demands on synchronism and dynamics. This is where EtherCAT comes into play. This protocol was developed specifically for motion control and drive technology. A typical example is a packaging machine in which several servo drives must work synchronously to precisely position, cut, or seal products. EtherCAT makes it possible to update the positions of all axes almost simultaneously, resulting in very smooth motion sequences. EtherCAT is also frequently used in robotics, for example in articulated robots whose joints must work in precise coordination with each other.

EtherNet/IP has established itself particularly in internationally oriented industrial plants, especially in North America, where close integration of automation and IT is required. Typical application scenarios are process plants in which controllers, frequency converters, and operating devices communicate with each other via EtherNet/IP. At the same time, production and machine data are continuously transmitted to central data acquisition systems to enable monitoring, analysis, and optimization. While the real-time requirements for this Ethernet industry variant are comparatively moderate, the easy integration of devices from different manufacturers plays a central role.

Modbus TCP is an open Ethernet variant that is particularly impressive due to its low complexity and high compatibility. In practice, it has an application in energy and building management systems. For example, energy meters, temperature or pressure sensors are connected to central control systems via Modbus TCP in order to regularly query and evaluate data.

SERCOS III is a real-time Ethernet protocol that is used in particular in drive technology and high-precision machine tools. In CNC milling or turning machines, SERCOS III ensures that spindles, axes, and other mechanical components are precisely synchronized.

POWERLINK Ethernet is also frequently used in classic mechanical engineering, e.g., in packaging or assembly systems. POWERLINK ensures that all participants in the network communicate with each other synchronously and receive control commands at precisely defined times.

TSN is currently used primarily in pilot projects and new systems, e.g., in modular production systems in the automotive industry. There, control data, diagnostic data, and IT data are transmitted via a common network without the different data streams influencing each other. Special Ethernet variants for building and process automation also have clear areas of application. BACnet IP, for example, is used in large industrial or office buildings to control heating, ventilation, and air conditioning systems. HART-IP is found in the process industry, for example in chemical plants, where measuring devices such as pressure or flow meters are connected via Ethernet. In both cases, the focus is on reliability, standardization, and long-term maintainability, rather than strict real-time requirements. In summary, it can be said that the choice of the appropriate Ethernet variant always depends on the specific application. While standard Ethernet and simple Industrial Ethernet solutions are ideal for data communication and visualization, highly deterministic protocols such as EtherCAT, SERCOS III, or POWERLINK are used where movements and processes must be precisely synchronized. PROFINET and EtherNet/IP bridge the gap between classic automation and modern IT integration. With TSN, a future is also emerging in which different requirements can be combined on a common Ethernet infrastructure.