What is Industrial Ethernet – Solutions and Protocols
1. Switching technology: This involves an effective collision domain division mechanism within a shared local area network (LAN). Switches connect different areas, reducing collisions and transmission errors. This minimizes collisions and improves system determinism.
2. High-speed Ethernet: The occurrence of collisions is related to the load; the greater the load, the greater the probability of collisions. Increasing the communication speed of Ethernet can reduce the network load.
3. IEEE 1588 time synchronization mechanism
IEEE 1588 defines a Precision Synchronization Protocol (PTP) for precise clock synchronization in measurement and control networks, relating to network communication, local computation, and distribution. This protocol is not exclusive, but it is particularly well-suited for Ethernet-based technologies, achieving microsecond-level accuracy. It uses a time stamping mechanism to synchronize local time. Even when synchronization control signals fluctuate during network communication, its accuracy remains satisfactory. This makes it especially suitable for Ethernet-based systems. By adopting this technology, the Ethernet TCP/IP protocol can operate in high-precision network control systems without major modifications. Its accuracy in area buses far exceeds that of existing systems. Furthermore, using Ethernet TCP/IP-based network technology at all levels of an enterprise offers significant advantages.
What is Industrial Ethernet - Fieldbus Analysis
Currently, there are approximately forty types of fieldbuses in the world. These fieldbuses are mostly used in process automation, medical fields, manufacturing, transportation, defense, aerospace, agriculture, and building applications. Current industrial bus networks can be classified into three categories: 485 networks, HART networks, and Fieldbus networks.
01, 485 network
RS485/MODBUS is a popular industrial networking method, characterized by its simplicity and ease of implementation, and the abundance of instruments that support RS485. Instrument manufacturers are increasingly switching to RS485/MODBUS for the simple reason that RS485 adapters are not only inexpensive but also come in a wide variety of types. At least in the low-end market, RS485/MODBUS will remain the primary industrial networking method.
02. HART Network
HART, proposed by Emerson, is a transitional bus standard. Its main feature is the superposition of digital signals on top of 4-20 mA current signals. However, the protocol is not truly open; access is only available through Emerson's foundation, which incurs a fee. HART technology is primarily monopolized by a few large foreign companies. While some domestic companies have been developing it in recent years, they haven't yet reached the level of their foreign counterparts. Many smart meters now come with HART cards supporting HART communication. However, in China, this functionality isn't widely used for networked device monitoring; at most, it's used for parameter setting via handheld devices. In the long run, due to HART's low communication speed and difficulties in networking, the application of HART meters is expected to decline.
What is Industrial Ethernet? - Key Points for Promotion
What is driving the adoption of Industrial Ethernet?
The immense success of Ethernet solutions over traditional fieldbuses is primarily due to the excellent bandwidth and speed of Power over Ethernet (PoE), as well as the outstanding flexibility and cost-effectiveness resulting from a large, established product ecosystem. Furthermore, Ethernet is a familiar technology that first entered office LANs decades ago.
Another major driver of Ethernet adoption is the rise of the Industrial Internet of Things (IIoT). The sheer scale of the IIoT and its countless devices and IP networks are pushing hardwired transmitters and serial fieldbuses to their limits. This trend can be seen, for example, in the evolution of the HART family of protocols.
More specifically, the widespread adoption of WirelessHART means that many dynamic variables used for measurement are now exchanged by the devices themselves, rather than the movement of single variables in many traditional automation protocols. Mapping all these numbers in Modbus RTU registers would be a slow and arduous task. Serial-based protocols such as Modbus RTU are also unsuitable for managing smart devices, which is becoming increasingly important for the IIoT.
