Patching Precautions - TM-11-5895-1012-100079

TM 11-5895-1012-10

equipment is available, spare circuits, which corre-

channels, rerouting of circuits, or cause interruption of

spond to the DCS options in use at the station, may be

service must generally be reported to higher headquar-

established to permit rapid restoration of circuits by

ters. The specific reporting procedures to be followed

in-station patching.

are contained in the current station SOP.

a Equipment Substitution. No operations reports

4-18. Patching Precautions

are required for the substitution of equipment during

a. Temporary Measure. The use of patchcords to set

routine maintenance operations. A Failure Report

up or rearrange circuits is intended as a strictly tem-

must be completed, however, if an equipment failure

porary measure. Service restoration patches should be

has occurred.

taken down as soon as the fault condition has been

b. HF Patching. Except as authorized in the current

cleared. In some cases, circuit orders may be issued

SOP, group patches may not be performed in the

which specify that patchcords be used to set up or rear-

multiplex ares without prior coordination with, and

range a circuit to fill an emergency or temporary re-

approval of, the DCA and ACC. Notice must be fur-

quirement. Such orders may specify, for instance, that

nished to the DCA and ACC following completion of

circuits be established without delay by patching, and

the HF patching operation.

c. Channel Substitution. The DCA sad ACC must be

later by cross-connected at the frame to make a per-

informed when a circuit is transferred to a spare chan-

manent configuration. The patch is to be taken down

as soon as the normal circuit is arranged. The opera-

nel, or to a channel of lower priority circuit. The notice

tional objective is to keep the jackfields as free of

should specify the time, circuit number, channel desig-

patchcords as possible. A multiplicity of patches in a

nator, reason, and expected duration of the rearrange-

ment. This report is normally submitted after-the-fact,

jackfield frequently results in confusion as to the pur-

since the Technical Controller must take immediate

pose and authority of the patches, and whether they

action when patching is required to restore service.

are still required. To preclude such confusion, identifi-

When it is necessary to preempt a lower priority cir-

cation tags should be attached to any pat&cord setup

cuit to obtain a substitution channel, the using agency

which is to be left in place at the end of a Technical

must also be informed. When the circuit is restored,

Controllers duty shift. The identification tag should

the using agency and higher headquarters must be

contain the following minimum information: circuit

notified.

number, terminal locations, using agency, mode of

operation, authority, and time to be taken down.

4-20. Patching Operations Condu

b. Patching Technique and Sequence. When patch-

the VF Patching Facilities

ing operational circuits, it is essential that interrup-

a. General. The jackfields associated with the VF

tion, or service outage resulting from the actual patch-

patching facilities are used to gain access to signals in

ing procedure, be kept to an absolute minimum dura-

voice-frequency (300 to 3400 Hz) circuits for monitor-

tion. In most patching operations, it is possible to limit

ing purposes, and to perform circuit rerouting, test

the effect on a VP circuit to a momentary click, and on

measurements, level adjustments, and restoration of

a TTY circuit to a few garbled characters. This mini-

service by equipment substitution. Representative

mum effect can be realized, however, only when the

patching operations are given in b, c, and d below. The

Technical Controller selects and follows the correct se-

patch panels and jacks used are discussed in Chapter 2.

quence in inserting the plugs in the jacks. The order in

The patching operations are shown in figures 4-1

which this is done is important. Each of the many pos-

through 4-3.

sible patching operations must be considered individu-

NOTE

ally to determine the optimum order of events in the

The patching operations described below do

patching procedure. Experienced Technical Con-

not take into consideration the extension of

trollers always take a moment to think out the whole

E&M signalling leads through a patch panel.

patching procedure before plugging into the jacksets.

Where there is a signalling lead extension,

In general, the spare or alternate signal path should

use additional patch cords to transfer over all

be set up first. The plugs should then be loosely set in

portions of the circuit.

the proper NORMAL-THROUGH jacksets, located in

the signal path of the circuit to be transferred. Finally,

b. Transfer of a Circuit to a Spare Multiplex

in a coordinated procedure, the plugs should be simul-

Channel (fig. 4-1). The situation requires, for test or

taneously pushed all the way into the NORMAL

maintenance purposes, that the user assigned to

THROUGH jacksets at two locations that constitute

channel 5, be transferred to channel 2. This patch is

the end of the substitution path.

made at the equal level patch panel (fig. 2-15) and the

procedure is the same for Station A and Station B.

4-19. Reporting Patching Operations

(1) Place two patch cord plugs loosely into channel

Patching operations which result in reconfiguration of

2 REC LINE and TRANS LINE jacks.

4-6