56
SCAN-LAN VI
6.6 Noise
Impulse Noise is non-repetitive electrical spikes or pulses caused by external
electromagnetic fields. It is one of the primary causes of inconsistent
performance on unshielded twisted-pair networks.
The Noise test counts noise impulses (spikes) greater in amplitude than a
minimum threshold on an idle twisted-pair cable segment and provides
a report of the results.
Noise results for all selected cable types are compared to the IEEE 802.3
10BASE-T impulse noise specification. The default noise-threshold setting is
260 mV. Refer to
Chapter 9, Setup
, for information on how to change this
value.
The Noise test reports time duration of the test, average number of impulses
in the last second, peak number of impulses in any one second, and the time
of occurrence since the start of the test.
6.6.1 R
UNNING
N
OISE
The Noise test runs continuously until stopped by the user.
1. If testing a twisted-pair cable, connect one end of the cable under test to
the main unit and the other end to the remote unit. Set the remote unit’s
dial to REMOTE.
2. Set the main unit’s dial to EXTENDED FUNCTIONS. Scroll through the
list of functions until NOISE is highlighted.
3. Press ENTER to select the test. The test begins immediately. (Press the
arrow keys to change the cable test standard.)
F1
F2
F3
F4
Summary of Contents for SCAN-LAN VI
Page 2: ......
