Wizard DP Extender
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Page 42
Appendix D. Link cable interference protection
While the Category rating (e.g. CAT 5e, CAT 6a, etc.) determines the electrical performance of a cable, another vital part of the
overall cable specification is its protection from interference. As cabling distances and data rates increase, so too does the suscep-
tibility to interference, from both external and internal sources.
Proximity to other electromagnetic sources are the main external threat and these can be subdued using overall screening that
surrounds all four of the cable pairs. However, interference is also possible from neighbouring twisted pairs within the same cable
and this can be just as hazardous to data integrity. Such
crosstalk
is countered by shielding each cable pair separately.
Within each Category rating, you can specify different combinations of external screening and internal shielding to suit the envi-
ronment into which the link is being placed. Please see the section
Tips for achieving good quality links
for suggested com-
binations.
Interference protection codes
Interference protection is now classified in the following manner:
Name
Overall
Pair
Screening Shielding
U/UTP
û
û
F/UTP
ü
û
U/FTP
û
ü
S/FTP
ü
ü
or S/STP
or PiMF
U/UTP
F/UTP
U/FTP
S/FTP
S/STP
PiMF
Pair shielding
Overall screening
Outer sheath
General cable anatomy
where
U
= unshielded
F
= foil shielding
S
= braided shielding
PiMF
= Pairs in Metal Foil
Overall
screening
Pair
shielding
Twisted
Pair
U / UTP
