Graphical Tdr - Pockethernet Manual

Graphical TDR

This features allows you to measure the imperfections of a cable along its
whole length or a section of it. A short electrical pulse is sent down the cable,
which is reflected from imperfections (short circuits, split pairs, impedance
mismatches, open ends) or absorbed by proper termination (another ethernet
port). The cable is measured from its beginning until the distance that is set
by the slider. For a distance up to 30 meters / 100 feet, a high-resolution plot
is conducted. The maximum distance is 300 meters / 1000 feet.
On the plot graphics, the horizontal axis shows the distance, while the
vertical axis shows any reflections of the initial test pulse. The 4 color lines
correspond to the 4 wire pairs in the cable according to the TIA settings.
Short circuits show up as a negative reflection, open ends as a positive one,
while with a proper termination the graph is completely flat.
Small imperfections in the +/- 10 range can be caused by cable extenders or
patch panels, which can be conveniently detected by this feature.
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