Cabletron Systems THN-MIM Manual De Usuario

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INSTALLATION 
 
Page 2-3
The THN-MIM7593 does not report false collisions to the IRM. 
However, if a non-Cabletron Systems Ethernet device is connected 
to the segment, it is possible for false collisions to be generated. 
Non-Cabletron System devices should be thoroughly tested before 
using them with the THN-MIM7593.
 
2.2.3
Thick-net Segments
 
50 ohm Ethernet type coaxial cable must be used when making up 
thick-net cable segments.
Each thick-net cable segment connected to a THN-MIM module 
must be no longer than 500 meters (1640 feet) in length.
When making up networks requiring shorter cable runs, Ethernet 
standard length 23.4, 70.2, and 117 meter cable sections should be 
used. These cable sections may be connected together by a barrel 
connector to form a cable segment.
Use of non-standard cable lengths may result in impedance 
mismatches causing reflections to occur. These reflections may 
cause data errors.
A 50 ohm terminator must be connected to the far end of the thick 
segment.
A BNC to N-Series adaptor must be connected to the applicable 
BNC port to attach the thick-net segment to the module.
A maximum of 100 transceivers may be attached to a thick-net 
cable segment, and these transceivers must be at least 2.5 meters 
apart throughout the length of the cable. Transceivers should be 
placed on the black bands that run along the cable that are marked 
at 2.5 meter intervals.
For safety, only one end of a thick-net segment should be connected 
to earth ground. Connection to earth ground at more than one point 
on the segment may allow for the occurrence of dangerous ground 
currents. The BNC ports of the THN-MIM are connected to earth 
ground. This eliminates the need for grounding a thick-net 
segment connected to the module.