Fluke CableAnalyzer DSP-4100, Руководство пользователя

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DSP-4000 Series
Users Manual
B-6
Equal Level Far End Crosstalk (ELFEXT)
The difference between the FEXT and the attenuation of the disturbed wire pair (in dB).
Good cabling performance corresponds to high ELFEXT values, which result when FEXT
is much higher than attenuation.
Ethernet
A local area network protocol using Carrier Sense Multiple Access with Collision
Detection (CSMA/CD). Ethernet is available with four cabling alternatives: thin coaxial,
standard (thick) coaxial, twisted pair, and fiber optic. This protocol uses 10 Mb/s baseband
transmission and is defined by the IEEE standard 802.3.
Far-End Crosstalk (FEXT)
The amount of coupling loss (in decibels) occurring when a signal generated at one end of
one cable pair is received as crosstalk at the other end of another cable pair. Higher FEXT
levels correspond to better cabling performance.
Flash Memory
Computer memory that requires no power to maintain its contents, yet, unlike ROM, can
be reprogrammed while installed in a system.
Foil-Screened Twisted Pair (FTP)
See Screened Twisted Pair.
Hardware Flow Control
A hardware method of controlling data flow between two devices. The receiving device
tells the sending device to start or stop data transmission by sending control signals on a
cable wire that is dedicated to flow control signals.
HDTDR

High-definition time domain reflectometry. A technique used for finding cabling faults and
measuring cabling length and characteristic impedance. A test pulse applied to the cabling
is reflected by impedance discontinuities along the cabling (such as a short or an open).
The cabling’s characteristics are determined by timing the duration between the test pulse
and the reflection and analyzing the shape of the reflected pulse.