Serial hubs expand serial ports to multiple ports and allow connectivity of multiple serial devices such as industrial instruments, point-of-sale (POS) terminals, and barcode printers.

Serial hubs support many different serial communication protocols including RS232, RS422, and RS485. Users can connect hubs in serial to expand a network and provide easy connectivity for plugging in other devices. Hubs plug into serial ports on the computer and provide four or more ports for peripherals. The peripherals themselves may also contain hubs. For example, a monitor may have a built-in USB hub in order to provide a convenient desktop location for plugging in other devices. USB hubs are commonly available with 4 or more ports.

Serial hubs may contain a serial adapter, which can be used to connect a USB serial connection to a computer that provides 4 or more rs232 serial connections.  Serial hubs can be used in many different applications. Serial hubs can be designed for versatile support of applications in industrial automation, process control, manufacturing, and across a broad range of commercial operations including retail POS, hospitality, back office, medical, and security systems.  Serial hubs may be designed to operate at different speeds; older standards such as RS232 and RS485 networks may be limited to slower speeds, while newer standards like USB serial devices may be able to operate at much higher speeds.

Some serial hubs have the ability to operate wirelessly allowing the connection of serial devices over a distance without the connection of wires.  While some serial hubs may operate transparently without requiring support software installation, others may require the installation of drivers to operate.  Serial hubs are sometimes used in conjunction with other serial devices such as a serial adapter or a serial server.  These devices convert between different network protocols to allow the use of serial devices across a wider range of networks.

Serial hubs should adhere to Electronic Industries Association (EIA) standards for RS232, RS422 and RS485 for data communication.