The RTXM228-551 850nm VCSEL 10Gigabit Transceiver is designed to transmit and receive serial optical data links up from 8.5 Gb/s to 10.51875 data rate over multimode fiber. The Transceiver is compliant with FC-PI-4, 10G FC, IEEE 802.3ae, SFF-8432, and applicable portions of SFF-8431. The transmitter converts serial CML electrical data into serial optical data. An open collector compatible Transmit Disable (Tx_Dis) is provided. When TX_DIS is asserted High, Transmitter is turned off. The receiver converts serial optical data into serial CML electrical data. An open collector compatible Loss of Signal is provided. The RX_LOS signal indicates insufficient optical power for reliable signal reception at the receiver. Digital diagnostics functions are available via a 2-wire serial interface, as specified in SFF-8472.