Fluke DSP-100, DSP-2000 user manual Return Loss RL, Items on the RL Results Screen Description

Autotest 3

Autotest Results for Twisted Pair Cable

ACR@REMOTE

The ACR@REMOTE test is identical to the ACR test, except that the ACR values are calculated using NEXT@REMOTE values.

Return Loss (RL)

The RL test measures the difference between a test signal’s amplitude and the amplitude of signal reflections returned by the cable. The results of the RL test indicate how well the cable’s characteristic impedance matches its rated impedance over a range of frequencies.

The first RL results screen shows the cable pairs tested, the worst-case RL margin, and a PASS or FAIL result for each pair. To see detailed results for the cable pairs, use DUto highlight a pair; then press @View Result. Table 3-8 describes the items on the RL results screen.

Item

Pair

Result

RL

Frequency

Limit

Margin

Table 3-8. Items on the RL Results Screen

Description

The cable pair relevant to the results.

The overall result for the RL test. A PASS result means that the measured RL is lower than the specified limit for the selected test standard. A FAIL result means that the measured RL is higher than specified limit.

The worst-case return loss. Worst-case RL is the measured RL value that is closest to exceeding specifications. If the RL exceeds specifications, the value displayed is the value that exceeds specifications by the greatest amount.

The frequency where the worst-case RL occurred.

The specified limit for RL at the worst-case frequency. The limit is defined by the test standard selected.

The difference between the worst-case RL and the Limit. A positive number means that the worst-case RL is better than the limit. A negative number means that the worst-case RL exceeds the limit.

3-17