UTP cable length measuring instrument feturing TI's interface circuits

Time Domain Reflectometry (TDR) diagnostic features of Ethernet physical transceiver chips are explored for evaluating their applicability for construction of an UTP-cable length-measurement and diagnostic instrument. The instrument is mainly intended as an aid during installation and for post-installation documentation. Dithering method is applied for length measurement to increase the resolution, based on physical patch-cable switchover and/or discrete component cable emulation and/or programmable delay-line delay-dithering. A practical experiment with length dithering using cable patches confirms the feasibility of the idea.