USB to RS232 Hub manufacturers take you to understand how the Hub is classified by structure and function
USB to RS232 Hub Manufacturers tell you that by structure and function, hubs can be divided into three categories: unmanaged hubs, stackable hubs and chassis hubs. (1) Unmanaged hubs. USB to RS232 Hub Manufacturers tell you that the simplest hubs provide a central network connection via an ethernet bus, wired together in a star. This is called an unmanaged hub and is only used in very small networks of up to 12 nodes (in rare cases, more). Unmanaged hubs do not have management software or protocols to provide network management functions. Such hubs can be passive or active. Active hubs are used more.
(2) Stacked hubs. USB to RS232 Hub Manufacturers tell you that stackable hubs are slightly more complex hubs. The most notable feature of a stackable hub is that 8 repeaters can be directly connected to each other. This allows the network to be expanded simply by adding hubs and connecting them to the already installed hubs, which is inexpensive and easy to implement.
(3) Chassis hub. USB to RS232 Hub Manufacturers tell you that a chassis hub is a modular device into which many types of modules can be inserted on its backplane circuit board. Some hubs have redundant backplanes and power supplies. Also, some modules allow users to replace failed modules without shutting down the entire hub.
USB to RS232 Hub Manufacturers tell you that the backplane of the hub prepares multiple buses for the plug-in modules, and these plug-in modules can adapt to different segments, such as Ethernet, Fast Ethernet, Fiber Distributed Data Interface (FDDl) and Asynchronous Transfer Mode (ATM). Some hubs also contain bridges, routers, or switching modules. Active chassis hubs may also have retiming modules to correlate with amplified data signals.
The above is the USB to RS232 Hub manufacturer's introduction and analysis of how the Hub is classified by structure and function, hope it helps you.