Fluke DSP-2000, DSP-100 user manual Next Test, Items on the Next Results Screen Description

DSP-100/2000

Users Manual

NEXT Test

The NEXT test measures the crosstalk between cable pairs. This crosstalk value is expressed as the difference in amplitude (in dB) between the test signal and the crosstalk signal. NEXT is measured from the main-unit end of the cable over a frequency range defined by the selected test standard.

If the NEXT test fails, you can use the TDX analyzer to locate the source of the crosstalk on the cable.

The first NEXT screen displays the cable pairs tested, the worst-case NEXT margin, and the test result for each set of pairs.

To see detailed results for the cable pairs, use DUto highlight the pairs; then press @View Result. Table 3-4 describes the items on the NEXT results screen.

Item

Pairs

Result

NEXT

Frequency

Limit

Margin

Table 3-4. Items on the NEXT Results Screen

Description

The cable pairs relevant to the results.

The overall result for the NEXT test. A PASS result indicates that the NEXT between the cable pairs was higher than the specified NEXT for the selected test standard. A FAIL result indicates that the NEXT was lower than specifications.

The worst-case NEXT. Worst-case NEXT is the measured NEXT value that is closest to falling below specifications. If the NEXT falls below specifications, the value displayed is the value that falls the farthest below specifications.

The frequency where the worst-case NEXT value is measured.

The lowest NEXT value acceptable for the worst-case frequency.

The difference between the worst-case NEXT value and the limit. A positive number means that the measured NEXT value is higher than the limit (PASS). A negative number means that the NEXT is lower than the limit (FAIL).

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