Comparison between the hottest can bus and PROFIBU

  • Detail

Comparison of CAN bus and PROFIBUS bus

controller area net is a kind of field bus, which is mainly used for various process detection and control. Can was originally designed for vehicle monitoring and control by Bosch Company in Germany. At present, can has been gradually applied to other industrial control and has become an iso-11898 international standard

can bus has the following characteristics:

1 Can can be a peer-to-peer structure, that is, a multi host working mode. Any node on the network can actively send information to other nodes on the network at any time, regardless of the master and slave, and the communication mode is flexible

2. Nodes on the can network can be divided into different priorities to meet different real-time needs

3. Can adopts non-destructive arbitration technology. When two nodes transmit information to the network at the same time, the node with low priority will automatically stop sending, and network paralysis will not occur when the network load is heavy

4. Can can send and receive data in the form of point-to-point, point to multipoint and point to network. The communication distance is up to 10 km (5 kb/s) and the number of nodes can reach 110

5. Can adopts a short frame structure, with 8 effective bytes per frame. It has CRC verification and other detection measures, and the probability of data error is small. In case of serious error, the CAN node has the function of automatic shutdown, which will not affect the operation of other nodes on the bus

6. The communication medium adopts low-cost twisted pair, without special requirements, and the user interface is simple, which is easy to form a user system


process field bus (PROFIBUS) is based on the experience of German Ministry of science and technology in the development of industrial automation control technology in the 1980s, It is considered that in order for researchers to systematically study the effects of different heat treatment systems on the microstructure and properties of alloys, it is necessary to standardize and publicize the existing network protocols defined by each company to meet the needs of the development of distributed computer automatic control system in the 1990s. It makes the automatic control equipment produced by different manufacturers compatible with each other in network communication, which is conducive to the improvement of the overall standardization level. According to this requirement, it was listed as a national project in 1987 and organized 13 large companies, such as Siemens, AEG, abb, etc. and 5 research institutes to study and complete the German national industrial fieldbus agreement standard for immediate shutdown after more than 2 years of efforts. The standard number is din19245

profibus protocol consists of three main parts:

1 Pro Plus central bank's standard reduction PROFIBUS-DP: polling communication mode is adopted between master station and slave station to support high-speed circular data communication, which is mainly used for field level communication in manufacturing automation system

2. Profibus-PA: the power supply and communication data are transmitted in parallel through the bus. It is mainly used in explosion-proof occasions facing the intrinsic safety requirements in the process automation system

3. Profib us-fms: defines the communication model between master station and slave station, which is mainly used for workshop level data exchange in the automation system

Copyright © 2011 JIN SHI