The Fiber Options Series 243D System supports high-quality, simultaneous transmission of video one-way and two-way transmission of control-data signals such as RS232, RS422, RS485, TTL, Manchester (or biphase), and relay/contact closure. These systems incorporate LED status indicators which greatly ease installation by pro v i ding a quick visual indication of system operation. Incorporating AGC circuitry, the systems require no field adjustments either at installation or periodically thereafter. These links may be ordered either as standalone units in a 502R Miniature Enclosure, or rack versions for mounting in Fiber Options' Series 515R Card Cage System or Series 517R Racking System, each unit occupying two rack slots.