What should be noted when purchasing industrial switches?

The industrial switch market is a mix of good and bad, with varying product quality. Therefore, when choosing a switch, it is necessary to consider several perspectives in order to ultimately determine the highest quality product. So, what should be noted when purchasing industrial switches? Let's take a look together.

1. Reliability

In industrial environments, reliability is undoubtedly the most important factor.

The factors that need to be considered include the hardware's tolerance to the working environment, such as the operating temperature range, EMC electromagnetic compatibility, installation, and power supply method. Industrial Ethernet devices differ from commercial Ethernet devices in that they generally adopt a compact design and rail installation method that is more suitable for on-site cabinet installation. To avoid equipment damage caused by rotating component failures, hardware equipment with no fan design should also be selected. In the parameter description of the product, there should be a detailed description of the working temperature range and electromagnetic compatibility. And accompanied by proof of relevant admission standards. After selecting reliable and stable hardware, attention should also be paid to the various redundancy methods that switches can provide, as well as fast fault diagnosis and recovery.

2. Security

Due to the openness of Ethernet, we have to consider the factor of network security when building automated networks. When selecting devices, users should choose switches with VLAN functionality to facilitate the division of network functions. Through VLAN partitioning, we can group and isolate devices within the network based on functionality, avoiding malicious human damage or misoperation. At the same time, users can use the 802.1x function in the switch to authorize and license devices that need to access the network, in order to distinguish between legitimate and illegal users.

3. Compatibility

Industrial Ethernet switches and other components of industrial Ethernet should be able to communicate using the standard TCP/IP protocol. Under no circumstances should there be any incompatibility issues between industrial Ethernet devices and commercial Ethernet devices. Industrial Ethernet devices should have corresponding capabilities and compatibility with different industrial fieldbus solutions. At present, the protocols for industrial switch component ring networks vary among manufacturers. In order to consider expansion and compatibility, users should also choose devices with MRP medium redundancy ring protocols, laying a foundation for future network expansion work. This protocol standardizes the ring network protocol, allowing devices of different brands to connect together to form a ring network.

4. Real time performance

The response time and jitter that the system can tolerate vary greatly in different application environments. Data frames in automated networks experience a certain delay every time they are forwarded from one device to another. Therefore, when choosing an industrial Ethernet switch, the first thing to consider is the port delay of the switch during the data frame forwarding process. In a standard factory automation control system, the system can tolerate a response time of no more than 10 milliseconds. In order to control the cumulative delay of data frames from the top to the bottom of the system, when selecting a switch, it should be noted that the switch port delay value should not exceed 10 microseconds.

5. Other

According to the actual application requirements, when choosing an industrial Ethernet switch, it is also necessary to pay attention to other commonly used functions. For example, QoS priority queues that differentiate between different business data priorities, or port mirroring functions that facilitate network fault diagnosis.

However, it should be noted that switches with more functions are not necessarily suitable for every application environment. The use of a large number of three-layer switches in the control layer and even the field layer greatly increases costs, while also damaging the application characteristics of industrial Ethernet. Users should choose appropriate features and purchase appropriate devices according to their needs to avoid unnecessary waste.

At the on-site level, industrial switches only need to provide port connections and there is no need to use complex network devices. At the control layer, it is generally necessary to select network managed switching units that support ring network functions to build redundant ring networks and provide effective diagnostic methods. For the connection of various control units, enhanced network management switches can be used to provide redundant connections and perform VLAN partitioning. When it is necessary to connect to the information layer network, complex devices such as layer three switches should be used.