Industrial Ethernet switches are specifically designed to meet the needs of flexible industrial applications, providing a cost-effective industrial Ethernet communications solution. The networking method focuses more on loop design. There are single-ring and multi-ring differences in the loop. There are also private loop protocols designed by various vendors based on STP and RSTP, such as RingOn, RingOpen open loop, FRP ring, and turbo ring.
The development of hubs has resulted in a device called an unmanaged switch. It enables routing of messages from one port to another, making them more intelligent than hubs. Unmanaged switches automatically detect the network speed of each network device. In addition, it has a function called "MAC Address Table" that recognizes and memorizes devices on the network. In other words, if port 2 receives a message with a specific identification code, then the switch will send all messages with that particular identification code to port 2. This intelligence avoids message collisions and improves transmission performance, a huge improvement over hubs. However, unmanaged switches cannot implement any form of communication detection and redundancy configuration.
The next generation of Ethernet connected devices is the managed switch. Compared to hubs and unmanaged switches, managed switches have more and more complex features and are much more expensive—typically three to four times as large as an unmanaged switch. Managed switches provide more functionality and are typically fully configurable through a network-based interface. It can automatically interact with network devices, and users can manually configure network speed and flow control for each port. Some old devices may not be able to use the automatic interaction feature, so manual configuration is indispensable.
Most managed switches also typically provide advanced features such as SNMP for remote monitoring and configuration (Simple Network Management Protocol), port mapping for diagnostics, VLANs for network device grouping (virtual local area network), The priority ranking function for ensuring the passage of priority messages, and so on. With a managed switch, you can set up a redundant network. With a ring topology, managed switches can form a ring network. Each managed switch can automatically determine the optimal transmission path and the alternate path, and automatically block the alternate path when the priority path is interrupted.