The ComNet TM FDX2HSD(M,S)(1,2)(EA,EB)/M data transceivers provide point-to- point or drop-and-repeat transmission of two independent simplex or duplex high-speed RS485 (2W) data signals over one optical fiber. The transceivers are transparent to data encoding allowing for broad-range compatibility. Models within this series are available for use with multimode or single mode optical fiber and feature built-in DIP switch-selectable bias and termination resistors for each data channel. Plug-and-play design ensures ease of installation requiring no electrical or optical adjustments. Each transceiver incorporates bi-color (Red/Green) indicating LEDs for monitoring proper system operation, including the location of fiber breaks. The FDX2HSD/M units are medium size surface mount modules, and they may be DIN-rail mounted by the addition of ComNet DIN rail adaptor plate (model DINBKT1, sold separately).