3Com 3CDSG10PWR User Guide - Page 210

210 CHAPTER 18: MANAGING DEVICE DIAGNOSTICS ■ Cable Fault Distance - Indicates the distance in meters from the port where the cable error occurred. ■ Last Update - Indicates the last time the port was tested. Configuring Cable Diagnostics The Diagnostics Page contains fields for performing tests on copper cables. Cable testing provides information about where errors occurred in the cable, the last time a cable test was performed, and the type of cable error which occurred. The tests use Time Domain Reflectometry (TDR) technology to test the quality and characteristics of a copper cable attached to a port. When performing cable tests consider the following: ■ During the tests, ports are in the down state. ■ The minimum cable length resolution is one meter, so if the cable is shorter than 1 meter the test will display "no cable". ■ An open cable or a 2-pair copper cable will display a cable fault distance of 0. ■ The maximum cable length is 120 meters.