Ethernet technology supports virtually all network protocols, making it widely used in data information networks. It boasts advantages such as high transmission speed, low power consumption, ease of installation, good compatibility, high openness, and support for a wide range of devices. In recent years, with the development of network technology and the increasing demands for network functionality in the industrial control field, Ethernet is gradually entering the industrial control field, forming a new type of Ethernet control network technology. The openness of industrial Ethernet provides unparalleled advantages in the seamless integration of industrial control networks and enterprise information networks.
Ethernet boasts advantages such as high transmission speed, low power consumption, ease of installation, and good compatibility. Because it supports virtually all popular network protocols, it is widely used in commercial systems. In recent years, with the development of network technology, Ethernet has entered the control field, forming a new type of Ethernet control network technology. This is primarily because industrial automation systems are developing towards distributed and intelligent control, making open and transparent communication protocols an essential requirement.
The introduction of Ethernet technology into the industrial control field has yielded significant advantages: 1. Ethernet is a fully open and fully digital network, allowing devices from different manufacturers to easily interconnect according to network protocols; 2. Ethernet enables seamless connection between industrial control networks and enterprise information networks, forming a fully open network for integrated enterprise-level management and control, as shown in Figure 2; 3. Low hardware and software costs, as Ethernet technology is already very mature, and hardware and software supporting Ethernet are highly valued and widely supported by manufacturers, with a variety of software development environments and hardware devices available for users to choose from; 4. High communication speed, as enterprise information systems expand in scale and become more complex, the demand for information is also increasing, sometimes even requiring the transmission of audio and video data. Currently, 10M and 100M Fast Ethernet are widely used, Gigabit Ethernet technology is gradually maturing, and 10G Ethernet is under research, with speeds much faster than current fieldbuses. 5. It has great potential for sustainable development. In this era of rapid information change, the survival and development of enterprises will largely depend on a fast and effective communication management network. Information technology and communication technology will develop more quickly and maturely, thereby ensuring the continuous development of Ethernet technology.
Ethernet's entry into industrial control also presents several challenges, primarily: 1. Real-time issues: Ethernet's CSMA/CD media access control method is inherently not real-time. Multiple nodes on a single bus compete for the bus, waiting for it to become available. This method struggles to meet the real-time requirements of industrial control, representing a technological bottleneck for Ethernet's entry into industrial control. 2. Adaptability and reliability to industrial environments: Ethernet is designed for office environments, requiring anti-interference capabilities and aesthetics to meet the demands of industrial settings. 3. Application layer protocols suitable for industrial automation control: Current application layer protocols defined in information networks do not adequately address the data structures and characteristics of real-time communication between field devices in industrial process control. Therefore, a unified application layer standard is needed. 4. Practical and network security: Practical safety must be considered if industrial Ethernet is used in hazardous environments such as flammable or explosive locations. Furthermore, because industrial Ethernet uses the TCP/IP protocol, it is vulnerable to network security threats, including viruses, unauthorized intrusions by hackers, and unauthorized operations. 5. Quality of Service (QOS) Issues: With the advancement of technology, the signals at the factory control layer are no longer limited to simple digital and analog quantities, but also include audio and low-resolution video signals. The network should be able to appropriately guarantee the real-time requirements according to different user needs and different content.
With the continuous development of network technology, the above-mentioned problems have been completely or partially resolved. 1. In recent years, high-speed switching Ethernet technology has emerged, using full-duplex communication, which can completely avoid the collisions in CSMA/CD and can easily implement priority mechanisms to ensure maximum utilization of network bandwidth and the best real-time performance. It completely avoids the potential inefficiencies of CSMA/CD, master-slave, tokens, etc.; 2. For network equipment manufacturers in different industrial environments, they have adopted special anti-interference measures to make them more suitable for industrial needs; 3. In terms of application layer protocols, users can add or remove TCP/IP protocol stacks as needed, and also need to develop network protocols that are more in line with industrial requirements; 4. Equipment manufacturers provide equipment adapted to industrial environments, using well-sealed, robust, and shock-resistant Ethernet equipment and connectors to address substantive security issues; multiple security mechanisms such as user passwords, data encryption, and firewalls are used to strengthen network security management, but solutions for network security issues in industrial automation control still need to be carefully studied; 5. With the improvement of network speed and the further improvement of network protocols, QoS issues have also been resolved.
Industrial Ethernet control systems offer significant advantages over other control systems, enabling their application across a wide range of industrial control fields. With the deepening research into integrated circuits, industrial Ethernet, and embedded Internet technologies, the era of Ethernet-based industrial control networks is fast approaching, becoming the most open industrial control network architecture. This new network system, echoing the development of fieldbuses in Ethernet, represents a revolution in traditional industrial control networks and will undoubtedly bring new possibilities to the industrial control field. However, in certain areas, such as automotive control systems and CNC machine tools, industrial Ethernet is unsuitable due to harsh operating conditions and high requirements for real-time performance and reliability. Current trends indicate that industrial Ethernet's entry into the field control level is undeniable. However, at least for now, it is unlikely to completely replace fieldbuses as the sole standard for real-time control communication. Existing fieldbuses will continue to exist for a considerable period, with the most likely scenario being the development of a hybrid control system where multiple networks coexist.
Disclaimer: This article is a reprint. If it involves copyright issues, please contact us promptly for deletion (QQ: 2737591964). We apologize for any inconvenience.
