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Industrial switches are different from civilian and commercial switches. They are not substantially different from other switches in the areas of transport layer, data link layer, and protocols when they are working. However, due to their unique office environment and work requirements, industrial automation switches have Many civil and commercial switches do not have the characteristics, it solves technical problems such as communication practicality, network safety factor, safety system and safety explosion-proof technology, and adopts some countermeasures suitable for industrial environments, such as moisture-proof and earthquake-proof move. Compared with ordinary switches, industrial switches mainly have two differences in function and performance: functionally, industrial Ethernet switches are closer to industrial network communication in function, such as communication and interconnection with various computer interfaces, and sinking of equipment. The real-time etc. of the rest and its machinery and equipment; the performance is mainly reflected in the difference of integrating the external environment monitoring system. In addition to many industrial environments such as: coal mines, ships and other particularly harsh environments, there are also environments with special requirements in the fields of EMI (electromagnetic compatibility), temperature, humidity, and antifouling. Among them, the influence of temperature on industrial computer equipment is the most common.
2. When to use industrial switches?
The industrial site must adopt a suitable industrial Ethernet switch instead of a cost-effective commercial switch. The importance of using an industrial switch in the industrial site can be clarified from the following levels.
Predictability Because the MAC layer protocol of the Ethernet interface is CSMA/CD, this contract causes conflicts on the Internet, and the ineffective measures are more obvious when the Internet load is too large. For an industrial Internet, if there are many contradictions, the data must be resent many times, which greatly increases the variability of inter-network communication. This type of variability from one place to another in an industrial control network necessarily produces a reduction in control system performance.
Practicality In industrial automatic control systems, real-time can be defined as the scalability of the reaction speed to something in the system. In other words, after an event occurs, the system must respond within an accurately predictable period of time. However, the practical requirements for information transmission in the industry are very strict, and data information is usually updated within tens of milliseconds. Also because of the CSMA/CD mechanism of the Ethernet interface, when a dispute occurs, the data message must be sent again. You can try 16 and then more. Obviously, this type of system for dealing with conflicts is at the cost of investing time. And once a disconnection occurs, even if it is only a few seconds, it may lead to the termination of the entire production and even equipment, life safety accidents.
Stability Because the Ethernet interface was not considered from the industrial network application at the beginning of its formulation. When it is used in industrial sites, extreme loads, severe impacts between wires, etc., all of these will inevitably lead to a decrease in its stability. In the working environment, the Industrial Internet must have good stability, recovery, and scalability. That is to ensure that when all components in an application system fail, it will not cause the application software, the computer operating system, and even the application system to crash and be paralyzed.