User guide

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OMNIScanner User Guide
ACR/Bandwidth
Attenuation to Crosstalk Ratio (ACR) is an indication of how much larger
the received signal is compared to the Near End Crosstalk (NEXT) on the
same pair. ACR is calculated from the measured NEXT and Attenuation.
The ACR value is computed at each measured Attenuation frequency. The
worst case ACR is reported for each pair combination.
Bandwidth is a measure of the usable frequency range of the link under
test. For most networks, this is the highest frequency at which the signal
can easily be distinguished from background noise. Depending on the
selected Autotest, the worst pair to pair ACR is typically 3dB.
In the ACR screen the Bandwidth is displayed at the
top of the screen. The pair combinations are located
in the column on the left side, followed by the mea-
sured ACR, the ACR limit, and the frequency. The
result for each pair combination is tagged with a
PASS or FAIL indicator.
Press or to toggle between ACR
results for OMNI Scanner and OMNI Remote .
Press (Graph) to view the graph for the
currently highlighted pair combination. The values for
Attenuation and NEXT are shown at the top of the
screen. Attenuation and NEXT graphs are displayed
for the frequency indicated by the cursor position.
Press (Pairs) to view Attenuation/NEXT graphs for other pair
combinations.
Press ESC to exit the ACR screen.