TX and RX are short for Transmit (TX) and Receive (RX). They refer to how data moves in a network. TX (Transmit): This is the port or process that sends data out of the device. Single-fiber media converters, also known as BiDirectional (BiDi) converters, are designed to transmit and receive data over a single strand of fiber. In fiber optics, data travels from the Tx port of one device to the Rx port of another, forming a two-way communication path. The transmitter (TX) is responsible for converting electrical signals into optical signals, which are then transmitted. A fiber optic transceiver (also called an optical transceiver) is a compact module that both transmits and receives data signals through optical fibers.