Devices that convert data between the serial and Ethernet interfaces allow engineers to take advantage of the best of two worlds. The "serial world" is the world of sensors, actuators, modems, and basic RS-485 networks that transmit data between devices and computers. The "Ethernet world" is the world of NICs (Network Interface Cards), the Internet, and open protocols used to whisk information from host to host.

The transformation between the serial and Ethernet interfaces takes place at the electronic signal and network protocol levels, such as in the transformation of data from the RS-232 format into a format suitable for a TCP/IP network. Carrying out such a transformation requires Device Server technology, in which a Device Server is a smart, standalone device with an embedded operating system and CPU that is large enough to contain its own operating system and the requisite software protocols, such as the TCP/IP stack. A Device Server also comes equipped with the required hardware interfaces, such as RS-232, RS-422, and RS-485 ports. The device server can transfer, and even process data between the serial and Ethernet interfaces to carry out pre-defined tasks.

Ethernet, and in a broader context, the Internet, have been adopted by the automation industry as its main communication backbone. By using open technologies, such as TCP/IP and Ethernet, control devices can be networked more quickly and with greater ease. Since most LANs are also connected to the Internet, this type of serial-to-Ethernet solution gives devices a data transmission outlet to any Internet host in the world.