Elaboration of eight major fieldbuses
1. Foundation Fieldbus (Foundation Fieldbus FF) Foundation Fieldbus is a protocol that was developed through the merger of two industry initiatives: the ISP agreement involving over 80 companies, including Yokogawa, ABB, Siemens, and Invensys, and the WorldFIP initiative led by Honeywell with more than 150 companies in Europe and other regions. This merged standard has become widely adopted in process automation due to its robust design and strong development potential. The protocol follows a simplified version of the ISO/OSI model, consisting of four layers: physical, data link, application, and user. It comes in two variants—H1 for low-speed communication (31.25 Kbit/s, up to 1900 m) and H2 for high-speed communication (1 Mbit/s or 2.5 Mbit/s, up to 750 m or 500 m). H1 supports bus power and intrinsic safety, while H2 allows for twisted pair, fiber optic, and wireless transmission. The signal encoding used is Manchester coding, ensuring reliable data transfer. 2. CAN (Controller Area Network) Developed by Bosch in Germany, CAN is a widely used protocol in discrete control systems. It has been standardized by the ISO and is supported by major semiconductor companies like Intel, Motorola, and NEC. The protocol operates at the physical and data link layers, using a short frame structure that enables fast transmission and strong noise immunity. It supports multi-master operation with non-destructive arbitration, allowing devices to prioritize communication. CAN can operate over distances up to 10 km at 5 kbps, and it can reach speeds of up to 1 Mbps. It is commonly used in automotive, industrial, and embedded systems due to its reliability and simplicity. 3. LonWorks LonWorks was developed by Echelon Corporation and later supported by Motorola and Toshiba. It uses the full seven-layer ISO/OSI model and employs an object-oriented design approach, making network configuration easier through the use of network variables. It supports multiple media, such as twisted pair, coaxial cable, fiber optics, and infrared, and offers data rates from 300 bit/s to 1.5 Mbit/s. Its maximum communication distance is 2700 meters at 78 Kbit/s. The LonTalk protocol is embedded in Neuron chips, enabling applications in building automation, home systems, security, and industrial control. 4. DeviceNet DeviceNet is an open-standard, low-cost network solution designed for device-level communication. Based on CAN technology, it provides transmission rates between 125 Kbit/s and 500 Kbit/s and can support up to 64 nodes per network. It uses a producer/consumer communication model, allowing devices to broadcast information efficiently. One of its key advantages is the ability to connect or disconnect devices without disrupting the network. The Open DeviceNet Vendor Association (ODVA) oversees its development and standardization. 5. PROFIBUS PROFIBUS is a fieldbus standard developed in Germany and Europe, covering three main types: DP (for high-speed data), FMS (for message-based communication), and PA (for process automation). It supports various topologies, including master-slave and multi-master configurations. The protocol can transmit at speeds ranging from 9.6 Kbit/s to 12 Mbit/s, with distances up to 1200 meters at lower speeds and 200 meters at higher speeds. Repeaters can extend the network to 10 km. It is widely used in industrial automation and supports both twisted pair and fiber optic cabling. 6. HART HART stands for Highway Addressable Remote Transducer and was originally developed by Rosemount. It allows digital communication over existing analog wiring, serving as a bridge between traditional analog systems and modern digital networks. HART operates at three layers: physical, data link, and application, and supports both point-to-point and multicast communication modes. It can be powered via the bus, meeting intrinsic safety requirements. HART is often used in conjunction with handheld programmers and host systems, offering flexibility in industrial environments. 7. CC-Link CC-Link, short for Control & Communication Link, was introduced in 1996 by Mitsubishi Electric and has since gained significant market share in Asia. It supports high-speed communication at 10 Mbit/s, making it ideal for real-time control applications. The protocol simplifies wiring and improves noise resistance, making it suitable for industrial settings. CC-Link covers both control and sensing layers, and it was recognized as a national standard in China in 2005, further boosting its adoption. 8. WorldFIP WorldFIP originated in Europe and was later split into two parts after merging with the ISP initiative to form Foundation Fieldbus. The European part remains independent, with a strong presence in France, where it holds around 60% of the market. It features a single-bus architecture that supports diverse applications without the need for gateways or bridges. WorldFIP is known for its compatibility with IEC61158 standards and its ability to integrate with other protocols like FF HSE, offering transparent connections and technical extensions. Other notable fieldbuses include P-Net, developed by Process-DataA/S and used in agriculture and food industries, and SwiftNet, which is popular in aerospace applications. These technologies continue to evolve, shaping the future of industrial communication and automation. Single Phase Voltage Stabilizer single phase voltage stabilizer zhejiang ttn electric co.,ltd , https://www.ttnpower.com