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TM 11-5895-878-14&P
Whenever such spare equipment is available, spare
coordinated  procedure,  the  plugs  should  be
circuits, which correspond to the DCA options in use at
simultaneously pushed all the way into the NORMAL-
'he station, may be established to permit rapid
THROUGH jacksets at two locations that constitute the
restoration X circuits by in-station patching.
end of the substitution path.
3-6. Patching Precautions
3-7. Reporting Patching Operations
a. Temporary Measure. The use of patchcords to
Patching operations which result in reconfiguration of
set up rearrange circuits is intended as a temporary
channels, re-routing of circuits, or cause interruption of
measure. Service restoration patches should be taken
service  must  generally  be  reported  to  higher
down as soon s the fault condition has been corrected.
headquarters. The specific reporting procedures to be
In some cases, circuit orders may be issued which
followed are contained in the current station SOP.
specify that patchcords be used to set up or rearrange a
a. Equipment Substitution. No operations reports
circuit to fill an emergency or temporary requirement.
are required for the substitution of equipment during
Such orders may specify, for instance, that circuits be
routine maintenance operations. A failure report must
established without delay by patching, and later be
be completed, however, if an equipment failure has
cross-connected at the IDF to make a permanent
occurred.
configuration. The patch is to be taken down as soon as
b. Group Patching.  Except as authorized in the
the normal circuit is arranged. The operational objective
current SOP, group patches may not be performed at
is to keep the jackfields as free of patchcords as
the site without prior coordination with, and approval of,
possible.
A multiplicity of patches in a jackfield
the CCOC and/or DCA following completion of the
frequently results in confusion as to the purpose and
group patching procedure.
authority of the patches, and whether they are still
c. Channel Substitution. The CCOC and/or DCA
required. To preclude such confusion, identification tags
must be informed when a circuit is transferred to a spare
should be attached to any patchcord setup which is to
channel, or to a channel of lower priority circuit. The
be left in place at the end of the technical controller's
notice should specify the time, circuit number, channel
duty shift.  The identification tag should contain the
designator, reason, and expected duration of the
following  minimum  information:
Circuit  number,
rearrangement. This report is normally submitted after-
terminal locations, using agency, mode of operation,
the-fact, since the technical controller must take
authority, and time to be taken down.
immediate action when patching is required to restore
b. Patching Technique and Sequence.
When
service.  When it is necessary to preempt a lower
patching -operational circuits, it is essential that
priority circuit to obtain a substitution channel, the using
interruption, or service outage resulting from the actual
agency must also be informed. When the circuit is
patching procedure, e kept to an absolute minimum
restored, the using agency and higher headquarters
duration. In most patching operations, it is possible to
must be notified.
limit the effect' on a VF circuit to a momentary click and
on a digital circuit to a few garbled characters.  This
3-8. Patching Operations Conducted at the
minimum effect can be realized, however, only when the
VF and Digital Patching Facilities
technical controller selects and follows the correct
a. General. The jackfields associated with the VF
sequence in inserting the plugs in the jacks. The order
patching facilities are used to gain access to signals in
in which this is done is important. Each of the many
the voice-frequency range (300 to 3400 Hz) and low
possible patching operations must be considered
level dc circuits for monitoring purposes, and to perform
individually to determine the optimum order of events in
circuit rerouting, test measurements, level adjustments,
the  patching  procedure.
Experienced  technical
and restoration of service by equipment substitution.
controllers always take a moment to think out the whole
Representative patching operations are given in b
patching procedure before plugging into the jacksets. In
below. The patch panels and jacks used are discussed
general, the spare or alternate signal path should be set
in chapter 2.  The patching operations are shown in
up first. The plugs should then be loosely set in the
figures 3-1, 3-2, and 3-3. Install control patches in red
proper NORMAL-THROUGH jacksets, located in the
circuits as required.
signal path of the circuit to be transferred. Finally, in a
b. Representative VF Patching Operations.
Objective
Situation
Procedure
Notes
At black patch jackfield  Test maintenance substitution
a. Place two patch cord
a. Identical procedures
(fig. 2-16), transfer of
of a. spare channel (No. 2)
plugs loosely into channel
required at both terminals
circuit to spare
for online (No. 5).
No. 2 RECLINE and
b. Procedures must be
channel (Fig. 3-2).
TRANS LINE jacks.
performed
b. Place plugs on other end
simultaneously.
of patch cords loosely into
channel No. 5 REC
EQUIP and TRANS
EQUIP jacks respectively.
3-3

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