Information Technology Reference
In-Depth Information
gender such as the male/female or jack/plug arrangement of most cabling systems.
These Data Connectors are mounted in a flush-mount plate at the workstation out-
let and in a patch panel (called a distribution panel) at the wiring closet, but are oth-
erwise identical in function to those used on cable ends. The distribution panel
typically contains 64 mounting positions for Data Connectors that terminate the end
of the station cables. It is customarily mounted on free-standing 19-inch rails. The
distribution panel also contains strain reliefs for the station cables. Data connector-
style cables, made using Type 6 cable, are used for patch cords in the wiring closet.
The connection at the workstation is a cable with a Data Connector at one
end and, at the other end, an appropriate connector for the particular equipment
to be connected. By simply terminating the cable with an appropriate connector,
the IBM cabling system can actually support quite a variety of data communica-
tions equipment, including coax, twinax, RS-232, and Token-Ring or Ethernet. In
the case of Token-Ring, a 9-pin d-shell connector is the appropriate connector at
the workstation.
The workstation's Token-Ring interface is 150 ohms, as is the STP station cable,
so no matching balun is needed. At the wiring closet end, many MSAUs are equipped
with Data Connector ports and use an ordinary Data Connector patch cable.
At the workstation location, the telecommunications outlet is composed of a
faceplate and a regular Data Connector, which terminates the station wire. Type 1
wire terminates in a single Data Connector, while Type 2 wire terminates in one
Data Connector and one telephone jack connector. Both connectors are designed to
clip into the faceplate. The IBM system offers two basic styles of faceplates. A Type
1 faceplate has a single Data Connector position, while Type 2 also includes a posi-
tion for an 8-pin RJ-45 style modular connector for telephone use. Conveniently, the
Type 1 outlet is used with Type 1 cable, and likewise, the Type 2 outlet with Type 2
cable. Both faceplates are available in surface mount as well as flush mount options.
Figure 3.4 shows a typical workstation outlet for use with Type 2 cable. Other ven-
dors offer Data Connector outlets in several other connector combinations.
The cable and connectors have a matching color code to make wiring simple.
However, the cable has a thick insulation and shielding that complicates the termi-
nation process in comparison to other types of twisted pair wire. This is undoubt-
edly why even the station cables are often terminated directly into a Data
Connector, rather than a punchdown arrangement, as is conventional twisted pair
wire. Cable is available in both plenum and nonplenum ratings and must be placed
appropriately. Termination of the Data Connector is described in Chapter 9.
The cabling system also includes Type 5 fiber-optic cable. The fiber and con-
nectors are basically the same as with other wiring methods. Termination and
descriptions of fiber-optic cable are described elsewhere in this topic.
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