Information Technology Reference
In-Depth Information
FIGURE 3.3
The Data Connector. (Courtesy of Hubbell Premise Wiring, Inc.)
IBM cabling system installations consist of a series of interconnected wiring
closets with star wiring to each workstation location. As we mentioned, either STP
or UTP pairs or a combination are contained in each station cable. The STP station
pairs are terminated in a Data Connector at each end. The Data Connectors have no
TABLE 3.3
IBM Cable System Cable Types
31BM Type
Pairs
AWG
Impedance
Shielding*
Rating
Type 1
2
22
150 ohms
e/f
o/b
Plenum
Type 2
2
22
150 ohms
e/f
o/b
Plenum
4
22
600 ohms
†
No Plenum
Type 3
4
24
150 ohms
No
Plenum or
nonplenum
Type 4
Not used
Type 5
2 fibers
100/140 µm
850 nm
No
Plenum
Type 6
2
26
105 ohms
e/f
o/b
Nonplenum
Type 7
Not used
Type 8
2-flat
23
150 ohms
e/f
o/b
Nonplenum
Type 9
o/b Plenum
*e/f = foil shield, each pair; o/b = overall braid shield †Impedance at 1 kHz, rather than 0.250 to 2.3 MHz.
NOTE: A-suffix cables are rated at higher frequencies than original 20 MHz rating cables (e.g., Type 1A is tested to
300 MHz).
2
26
105 ohms
e/f
