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12.3.2 Accuracy
When properly terminated, the WIREMAP reports the approximate cable length (in meters) for each of the
four cable pairs A, B, C, and D, the operation range being between 7 and 140 meters with 5-meter
accuracy.
Cable Termination
Proper termination of the CAT 5/6 cable requires 100-ohm differential impedance between the positive
and negative cable terminals. The IEEE 802.3 standard allows for a termination of as high as 115
Ohms or as low as 85 Ohms. If the termination falls outside of an accepted termination range, it will
be reported as anomalous by the WIREMAP cable diagnostics.
Open or shorted states on each of the cable pairs (A, B, C, D) are also recognized and their location
determined with 8-meter accuracy.
Coupling Between Cable Pairs
Shorted wires, improper termination, or high crosstalk resulting from an incorrect wire map can cause
anomalous coupling between cable pairs. All these conditions can prevent the PHY from establishing a
link at any speed.
The WIREMAP feature can correctly identify a cross-pair short location up to 100 meters with 10-
meter accuracy.
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