Test-Um NT750 - Manual (Page 16)

LanScaper
TM
6.0 INTERPETING CABLE TEST RESULTS -
Definition of Errors -
Short
Miswire
from to
reverse pair
Split Pair
The PASS icon will be on if the cable has all
pins properly connected per T568A/B. Neither icon will be on if the cable is cross-over (uplink)
cable. The FAIL icon will be on if there is any other condition. See Figure 6.1, Examples of
Wiring Errors.
The three classes of faults discussed below are in order of severity. The
severity has to do with the ability of a more severe error to mask lower severity errors. For
example, if there is a short in the cable, miswires and splits pairs may not be detected for the pairs
involved in the short fault.
- The pair has a low resistance connection from one wire of the pair to the other wire of the
pair, to any other wire in the cable or the shield. A short while testing with a remote is indicated by
the FAIL icon being on and flashing x's in the appropriate pin position of the second line of pin
numbers plus one or more error message lines listing all the pins shorted together. In the single-
ended test mode, the error messages only are displayed.
- A wire or both wires of a pair are not connected to the correct pins at the other end of the
cable. While testing with a remote, the wire map shows the pin numbers line 1 (main) line
2 (remote). A is a special case of a miswire in which the pair is wired to the correct
pair of pins or to another designated pair of pins, but the two leads are reversed. In single-ended test
mode, these types of errors are not detectable.
- A split pair is an error in the twisting of the wires together within the cable. The cables
generally are made up of eight wires twisted together in 4 pairs. These 4 pairs are designated as
pairs by the wiring standards and are intended to carry a signal and its return. 1&2, 3&6, 4&5 and
7&8 are the pairs designated by T568A/B for a RJ45 jack or plug. A cable can be wired with
correct continuity but not with correct pairing. This most often happens when the cable is
terminated consistently at both ends, but in the wrong order. A dynamic or AC test is required to
detect this type of error.
While testing with a remote, the
pin numbers on the second line of the wire map with split pairs flash and an error message is
displayed listing the pin numbers of the pairs involved in the error. In the single-ended test mode,
the error message is displayed.
If the only error is a split pair error, the cable has correct continuity. If
cross talk is not a concern, as in flat satin cable, the cable is good.