The PDS-220Fx series is a family of Programmable Device Servers, also known as "Serial-to-Ethernet gateway”, that are designed for adding optical fiber connectivity to RS-232/422/485 devices. The fiber-optic communications permits transmission over longer distances than other forms of communications because of the signals travel along them with less loss and no crosstalk. It has following important features: Immunity to electromagnetic interference (EMI) — Motors, relays, welders and other industrial equipment generate a tremendous amount of electrical noise that can cause major problems with copper cabling.