In the field of IIoT, industrial switches are key devices that connect field devices such as sensors, actuators, PLCs, and other devices with broader networks such as intranets or the Internet. Their choice is crucial. Precise selection of industrial switches can not only ensure the stability and efficiency of the network, but also facilitate subsequent maintenance and management. The following are professional recommendations for purchasing industrial switches based on different application scenarios:

1. Consider industry norms and certification
   The requirements for industrial switches may vary from industry to industry. For example, in high-risk situations such as rail transit or the petrochemical industry, products that meet the corresponding industry certification specifications should be selected. These certifications usually represent the reliability and safety of the product in that field.

2. Analyze the work environment
   Temperature and humidity, EMC electromagnetic compatibility, protection level: Industrial switches usually need to work in extreme environments, so their ability to adapt to extreme temperature and humidity, electromagnetic compatibility, and protection level should be considered. For example, some switches may have a protection level of IP40 or higher, as well as EMC industrial level 4 protection performance, which enables stable operation in harsh environments.

Power supply and redundancy design: For application scenarios that require continuous operation, such as intelligent manufacturing production lines or municipal water supply and drainage systems, switches with dual power redundancy design should be considered to ensure network operation can be maintained in the event of power failure.

3. Determine the communication rate and port requirements
   Choose the appropriate switch port speed based on business requirements, such as 100M, 1G, or 10G. At the same time, it is necessary to calculate the required number of RJ45 interfaces and fiber interfaces, and consider possible future expansion requirements. For example, in the intelligent manufacturing scenario where a large amount of data needs to be transmitted, gigabit or 10 gigabit ports may be more appropriate.

4. Selection between network management type and non-network management type
   Network management switch: Provides rich network management functions, such as ring redundancy, VLAN division, traffic control, and so on. It is suitable for scenarios with complex network architectures and requiring fine management, such as large factories or data centers.

Non-managed switch: Plug and play, simple configuration, suitable for scenarios with simple network architecture and no need for complex management, such as small workshops or offices.

5. Consider communication protocols and data conversion capabilities
   The industrial IoT gateway usually has a protocol conversion function, which can convert the communication protocols of different industrial devices into a unified standard format. When selecting a switch, it should also be considered whether it supports the required communication protocol and whether it has data filtering, preprocessing, and encryption functions.

6. Pay attention to edge computing capability
   For application scenarios that require fast response, such as real-time control in smart manufacturing or environmental monitoring in agricultural greenhouses, switches with edge computing capabilities should be considered. These switches can process data close to the data source, reducing the burden on cloud processing and improving response speed.

7. Brand and Cost-effectiveness
   When choosing an industrial switch, you should also consider the brand and cost performance. Well-known brands usually have more reliable product quality and better after-sales service. At the same time, the most cost-effective product should be selected according to budget and demand.

8. Practical cases and application experience
   Refer to the switch selection cases of other similar application scenarios to understand the performance and stability in actual applications. This helps to more accurately select switches that suit current needs.

Accurate selection of industrial switches requires comprehensive consideration of industry standards, working environment, communication rate, port requirements, network management functions, communication protocols, edge computing capabilities, brand and cost-effectiveness, as well as practical cases. Through comprehensive analysis and evaluation, the most suitable industrial switch for the current application scenario can be selected to ensure the stability and efficiency of the network.