Distribution Frames

TM 11-5895-1012-10

and type of orderwire circuits required at TCF's vary

made to provide transmission security. The criteria are

from site to site as dictated by station size, mission,

based on the concept of separation of red and black cir-

and location.

cuitry within the TCF and the DCS Station. In order to

accomplish this separation, there are two separate

2-21. Station

distribution frames provided. One to carry the red cir-

a. Types. Different types of cabling are necessary

cuits and the other to carry the black circuits.

for interconnection of the various equipment and key-

(1) Red Frame. The red frame is used to make

ing lines with the Primary and Equal Patch Bays

crossconnections between red circuits, patch panels,

as well as the transmission media equipment and sub-

and equipment, Red circuits are those circuits which

scribers.

carry or are cleared to carry, clear text, classified

(1) Voice frequency lines generally use appropri-

traffic. The red frame has a horizontal aide and a

ate sizes of shielded, single pair wires.

vertical side like any other combined distribution

(2) Direct current keying lines use individually

frame. Termination blocks are mounted on both tides

shielded pairs.

of the red frame. The vertical side is used to terminate

(3) Standard power cables are used to distribute

equipment, such as relay center equipment (send and

primary power to equipment

receive); the clear side of the COMSEC devices (send

(4) Coax and twinax are used for high speed data

and receive); the red side of battery isolation relays

MODEMS.

(send and receive); and for red circuit control, switch-

b. Routing. Cables are usually installed in one or a

ing, or monitoring devices. The horizontal side is used

combination of the following four methods; overhead

to terminate the red patch panels and the positive and

inclosed ducts, overhead open racks, cellular flooring,

negative rectifiers used to furnish battery. If any

traffic-carrying circuits which are approved for

and floor trenches.

c. Shielding. Prevention of mutual interference be-

handling clear text classified traffic without COMSEC

devices are in use, the lines will be connected to the

tween circuits that carry dc keying signals and circuits

vertical side of the red frame. The cables which are

that carry vf signals is accomplished by shielding the

dc keying circuits. Whenever feasible, separate racks

used to connect the items listed above to the red frame

or ducts should be used for each type of circuit.

are permanently connected to the left side of the ver-

tical blocks and to the bottom side of the horizontal

2-22. Distribution Frames

blocks. Cross-connections are made as required to con-

a. All in-station lines, equipment and channels, plus

nect battery, equipment, patch panel jack appear-

ances, and COMSEC devices together to form a circuit.

external cable pairs, terminate on a distribution

(2) Black Frame. The black frame is used to make

frame. A main distribution frame is used for terminat-

cross-connections between black circuits, patch panels,

ing outside lines and an intermediate distribution

lines and equipment. Black circuits are those circuits

frame is used to terminate in-station lines. However,

which carry encrypted traffic or unclassified, clear

in the interest of simplification and conservation of

text traffic. The black frame is the same configuration

apace it is common practice to use a combined distri-

as the red frame, having a horizontal side and a verti-

bution frame within the Technical Control Facility.

cd side. The horizontal side is used to terminate the

The distribution frame is made up of vertical and

audio and dc patch panels of the TCF and the positive

horizontal terminating blocks. The vertical blocks,

and negative battery supplies. The vertical side is used

used for terminating outside lines, are provided with

to terminate the following items: all landlines, both

protective devices to shield the cables and associated

audio and dc; the black or encrypted side of COMSEC

equipment from high voltages surges. The horizontal

devices; the black side of battery isolation relays; and

blocks are used to terminate the in-station cabling.

any black circuit control, switching, or monitoring de-

Cross connections are made on the distribution frame

vices used in the TCF. The various items are cross-con-

to obtain the desired circuitry.

nected as required to form the desired circuitry.

b. Jack appearances, in the Primary and Equal

Level Patch Rays, are terminated on the combined

2-23. Power Facilities

distribution frame as are the equipment associated

a. General. Each Technical Controller must be

with collocated facilities.

aware of power facilities used to provide primary and

c. Temporary arrangements of circuits and equip-

auxiliary, and emergency lighting power at the DCS

ment can be provided in the patch bays with the use of

Station. A detailed discussion of power facilities and

patch cords. However, all permanent changes should

equipment is given in paragraphs 2-24 through 2-28.

be made on the combined distribution frame in order

b. Primary Power. The term primary power is used

to minimize the requirements for patch cords in use at

at DCS Stations to denote the primary ac power source

any time in the Technical Control Facility.

to the DCS Station under normal operating conditions.

d. All cable runs and equipment connections are

2-27