USB DVI Optical Fiber KVM Extender (600m). The CE680 is a DVI Optical KVM Extender that overcomes length restrictions of standard DVI cables by using fiber optics to send high definition audio, video and control signals over longer distances. The CE680 can transmit KVM DVI signals very long distances - up to 600 m away from the source. The extender takes audio/video streams from the local source and serializes the data to pass it over a single 3.125 Gbps optical link, for resolutions up to 1920 x 1200 @ 60Hz, 24-bits, with picture perfect quality