LNK-IRS93 series is an industrial grade RS232/RS485/RS422 to fiber optic converter which converts a standard RS232/RS485/RS422 signal to a fiber optic link as to extend the signal up to 2Km on multimode fiber and 80Km on single mode fiber. The use of optical fiber communication solves the problems of electromagnetic interference, ground ring interference and lightning damage. It greatly improves the reliability, security and confidentiality of data communication, and can be widely used in various industrial control, process control, Stage Lighting Control and traffic control occasions.