Fluke DSP-2000 - Manual (Page 65)

Autotest
Autotest Results for Twisted Pair Cable
3
3-17
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
D U to highlight a pair; then press @ View Result. Table 3-8
describes the items on the RL results screen.
Table 3-8. Items on the RL Results Screen
Item Description
Pair The cable pair relevant to the results.
Result 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.
RL 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.
Frequency The frequency where the worst-case RL occurred.
Limit The specified limit for RL at the worst-case frequency. The limit is defined by the
test standard selected.
Margin 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.