LANTEK User Manual - Ideal Industries

Chapter 3
Structured Cable Field Calibration and Testing
Headroom Test
The Headroom measurement is a mathematical analysis of the data already existing
from previous tests. The calculated value is the sum of the Power Sum ACR test
(Power Sum ACR of the worst pair after the attenuation for that pair has been
normalized to 100 meters or 328 feet) and the additional margin between the worst
case PS NEXT and the limit for PS NEXT.
Headroom provides a simplified means of reporting the margin available in a single
cable run which will support an application with error-free performance. It also gives
an indication of additional margin which may be achieved through the utilization of
“enhanced” cable and connectors and careful installation practices.
Figure 3-22: Headroom Test Screen
Headroom Errors
The Headroom number, reported in dB, characterizes the worst-case margin found in
a single cable run. A large number is desirable, since it indicates a strong signal and
little noise interference. The pass/fail limit for Headroom is the same as Power Sum
ACR.
ANALYZE TEST SETUP
1. If the LANTEK tester has not been calibrated in the past 7 days, perform a field
calibration.
2. Configure the tester as required.
3. Select the Cable Type.
4. Disconnect the cable to be tested from all network equipment.
5. Connect adapters and patchcords to both the Display and Remote Handsets using
the connectors.
6. Connect the Display Handset patchcord to one end of the link and the Remote
Handset patchcord to the opposite end.
Note: Refer to Permanent and Channel Link testing for details regarding typical
connections.
7. Press ON/OFF to power up the Display Handset.
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