The VCT technology enables end users to remotely diagnose the quality and characteristics of the attached cable. With this feature it is possible to detect and report potential cabling issues such as cable opens, cable shorts, and impedance mismatches. The distance of the fault can be reported within one meter.
VCT can only be started if the corresponding adapter does not have a link up. If the link is up, DSP (Digital Signal Processor) is activated and reports the length of the cable.
To start VCT, proceed as follows:
The test is executed.
Depending on the result of the test, different states of the cable pairs, the distances (length) to the possible faults, and the test status are listed.
The following states of a cable pair are possible after VCT has been executed:
VCT reports the distance to the incorrect impedance in meters.
Copyright Marvell 2003