What are the Technologies of Industrial Ethernet Switch?

Industrial switch is also known as industrial Ethernet switch, which is used in the industrial Internet, industrial digital intelligent control field Ethernet communication equipment.

Because of the standard TCP / IP network, its openness, wide application and high performance and reliability, Ethernet communication technology has become the main communication standard in the field of industrial control. In this article, ATO industrial automation will introduce sommething about 3 technologies of industrial Ethernet switch.

• Pass-through technology. Once the switch understands the destination address of the data packet, it sends the data packet to the destination port. Typically, when the first six bytes of a packet are received, the switch already knows the destination address and can decide which port to forward the packet to. The advantages of the pass-through technology are fast forwarding rate, reduced delay and improved overall throughput. The disadvantage is that the switch starts to forward data before it has fully received and checked the correctness of the packet. In this way, when the communication quality is not high, the switch will forward all the complete packets and error packets, which actually brings a lot of junk packets to the whole network, and the switch will be misunderstood as a broadcast storm. In a word, the pass-through technology is suitable for the network environment with better link quality and fewer error packets.
• Store-and-forward technology. It requires the switch to decide how to forward the packets after all of them have been received. This allows the industrial switch to check packet integrity and correctness before forwarding. Its advantage is that there is no incomplete packet forwarding and the potential unnecessary data forwarding is reduced. Disadvantages: The forwarding rate is slower than that of the direct forwarding technology. Therefore, storage and forwarding technology is more suitable for the network environment with common link quality.
• Time delay technology. Switch delay refers to the interval between the time when a data packet is received from an industrial switch and the time when the data packet is copied to the destination port. There are many factors that affect the latency, such as forwarding technology and so on. Switches with the pass-through technology have fixed delays. This is because a direct-through switch determines the forwarding direction only according to the destination address, regardless of the overall size of the packet. Therefore, its delay is fixed, depending on the rate at which the switch interprets the destination address in the first six bytes of the packet. The switch using store-and-forward technology can only forward the packet after receiving the complete packet, so its delay is related to the packet size.