什么是現場總線？

現場總線（Fieldbus）是20世紀80年代末、90年代初國際上發展形成的，用于現場總線技術過程自動化、制造自動化、樓宇自動化等領域的現場智能設備互連通訊網絡。它作為工廠數字通信網絡的基礎，溝通了生產過程現場及控制設備之間及其與更高控制管理層次之間的聯系。它不僅是一個基層網絡，而且還是一種開放式、新型全分布控制系統。這項以智能傳感、控制、計算機、數字通訊等技術為主要內容的綜合技術，已經受到世界范圍的關注，成為自動化技術發展的熱點，并將導致自動化系統結構與設備的深刻變革。現場總線設備的工作環境處于過程設備的底層，作為工廠設備級基礎通訊網絡，要求具有協議簡單、容錯能力強、安全性好、成本低的特點：具有一定的時間確定性和較高的實時性要求，還具有網絡負載穩定，多數為短幀傳送、信息交換頻繁等特點。由于上述特點，現場總線系統從網絡結構到通訊技術，都具有不同上層高速數據通信網的特色。

目前國際上有40多種現場總線，但沒有任何一種現場總線能覆蓋所有的應用面，按其傳輸數據的大小可分為3類：傳感器總線（sensorbus），屬于位傳輸；設備總線（devicebus），屬于字節傳輸；現場總線，屬于數據流傳輸。下面讓我一起去認識主要的幾種總線。

What is a fieldbus?

Fieldbus (Fieldbus) is the international development in the late 1980s and early 1990s, which is used for field intelligent equipment interconnection communication network in the field of fieldbus technology process automation, manufacturing automation, building automation and other fields. It is the basis of the digital communication network of the factory, which communicates the connection between the production process site and the control equipment and the higher control management level. It is not only a basic network, but also an open and new fully distributed control system. This integrated technology with intelligent sensing, control, computer, digital communication and other technologies as the main content has received worldwide attention, become a hot spot in the development of automation technology, and will lead to profound changes in the structure and equipment of automation systems. The working environment of fieldbus equipment is at the bottom of the process equipment. As a basic communication network at the factory equipment level, it requires simple protocol, strong fault tolerance, good security and low cost. It has certain time certainty and high real-time requirements, and it also has the characteristics of stable network load, mostly short frame transmission and frequent information exchange. Because of the above characteristics, the fieldbus system has the characteristics of different high speed data communication networks from the network structure to the communication technology.

At present, there are more than 40 kinds of fieldbuses in the world, but no fieldbus can cover all applications, according to the size of its transmission data can be divided into three categories: sensorbus (sensorbus), which belongs to bit transmission; Device bus (devicebus), which belongs to byte transmission; Fieldbus, which belongs to data stream transmission. Let me go to know the main bus.