Why is it necessary to use industrial loop switches in industrial sites?

1, the industrial site environment is harsh

Because Ethernet in the design of the beginning, not from the industrial network application. When it is used in industrial sites, to deal with extreme working conditions, more serious inter-line influence, etc., these will certainly cause its stability to decrease. In the production environment, the industrial network must have relatively good stability, recovery, and scalability. That is, to ensure that the failure of any component of a network system will not cause the crash and breakdown of applications, operating systems, and even network systems.

Industrial Ethernet switches are designed in consideration of the complex situation of the industrial site, so as to better meet the industrial environment and give full play to the role of industrial switches.

The environment of the industrial site is more extreme than the usual environment, at least in the vibration, moisture, temperature will be worse than the usual environment, the design of the ordinary switch does not resist the ability to exist in the industrial environment, the ordinary switch can not work in such a harsh environment for a long time, often prone to failure, but also increase the maintenance cost, Commercial switches are generally not recommended to be used in industrial environments. In order to enable switches to be used in such harsh environments, switches adapted to such environments are produced. The reliability of industrial switches includes power failure, port interruption, alarm output by relays, redundant dual DC power input, active circuit protection, automatic circuit breaker protection of overvoltage and undervoltage. (Reliability varies slightly depending on the model)

The difference in function mainly refers to: industrial switches are closer to industrial network communication in function, such as interconnection with various fieldbuses, redundancy of equipment and real-time equipment, etc.; The characteristic difference is mainly manifested in the different parameters of the external environment. Industrial environment not only has a lot of such as: coal mines, ships and other very harsh environment, but also in EMI (electromagnetic compatibility), temperature, humidity and dust proof and other aspects of the environment has special requirements. The influence of temperature on industrial network devices is the most extensive.

2. The Ethernet network is overloaded

Because the Ethernet MAC layer protocol is CSMA/CD, this protocol promotes the existence of contradictions on the Internet, especially when the network load is too heavy, more obvious. For an industrial network, if there is a large number of contradictions, it must be repeated data information, which greatly increases the uncertainty of network communication. In industrial control network, this kind of uncertainty from one place to another will inevitably lead to the reduction of system control performance.

3. Strict real-time performance of industrial data

In industrial control systems, real-time can be defined as the predictability of the system's response time to an event. After an event has occurred, the system must respond within a time frame that can be accurately predicted. However, in the industry, the real-time standard of data information transmission is very strict, and the update of data information is often realized within tens of ms. Also because of the CSMA/CD mechanism on Ethernet, when a conflict occurs, the data must be re-uploaded for up to 16 times. It's not hard to see that such conflict resolution mechanisms come at a cost of time. And if there is a loss of line, even for a few seconds, it can lead to the termination of the entire production or even the safety of equipment and life.