Black Box SCAN-LAN VI, Manual

Page: 37 / 172

35
CHAPTER 4: Autotest
3. Press SAVE (F4) or ENTER at any time to save the Autotest results.
4. Press GRAPH (F2) to view a graphic display of the test results.
5. Press SEND (Fl) to send the results to the Remote Unit.
6. Press ESC to exit View.
4.3.1 L
INK
P
ERFORMANCE
S
CREEN
The Link Performance screen provides additional cable performance information.
This screen displays Headroom (HR) and the Power Sum Attenuation to Crosstalk
Ratio (PS-ACR) for all four wire pairs.
H
EADROOM
Headroom (HR) is displayed in decibels (dB) and indicates the measured
difference between actual cable performance and current Category 5 standards. A
high dB value for Headroom indicates a level of performance better than Cat 5.
4.3.2 P
OWER
S
UM
ACR
Power Sum Attenuation to Crosstalk Ratio (PS-ACR) is displayed two ways. The
column ACR=10 dB indicates the frequency at which the pair tested had an ACR
value of 10 dB. This is generally accepted to be the usable bandwidth of the cable
while still having enough signal strength to guarantee low data-transmission error
rates. The column ACR=0 dB indicates the frequency at which ACR measured
zero. This zero point is considered the absolute maximum usable bandwidth of
the cable.
F1
F2 F3 F4
LINK PERFORMANCE
1,2
3,6
4,5
7,8
22.9dB
15.8dB
16.5dB
22.6dB >250MHz
151.8MHz
165.3MHz
>250MHz
HR ACR=10dB ACR=0dB
SAVE SEND
>250MHz
>250MHz
>250MHz
>250MHz