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TM 11-5895-878-14&P
equipment should be used to restore disrupted service
channel or group is not operating satisfactorily, the
while the defective equipment is being restored.
station technical controller proceeds in the following
(3) During prolonged, or projected extended
out-ages,  the  technical  controller  should  request
(1) He determines if a single channel, a group
alternate routing instructions. Rerouting and preempting
of channels, or the entire area is affected.
is obtained from a list in SOP.
(2) The  controller  isolates  the  area  of
(4) As a last resort, the technical controller
should preempt lower priority circuits in order to restore
(3) He then endeavors to restore service as
service for high priority users. Every circuit, including
quickly as possible by selecting the most expeditious of
switchboard trunks as well as allocated circuits, is
the following methods: By substituting in-station spare
assigned a priority of restoration which must be adhered
equipment of identical configuration by patching to a
to in channel restoration.
Establishment of these
spare channel between stations (figs. 3-1 through 3-3)
priorities is performed on a worldwide basis by the
and/or by requesting that station maintenance personnel
Defense Communications Agency.
perform the necessary testing and equipment repairs.
c. Records and Reports. The technical controller
(4) In the event that the malfunction involves
who first determines that a fault exists or to whom a
a priority channel, and service cannot be restored
fault is reported by a user, is responsible for
expeditiously by the above methods, he preempts a
coordinating the fault isolation activities with distant
channel from the lowest priority user by patching.
station controllers, and he is responsible for appropriate
b. Single Channel. When it is determined that a
log entries and reports. When a fault has been isolated,
single voice channel is unserviceable, the station
an explanation of the nature of the trouble must be
technical controller takes the following action:
entered in the reporting station log, and the distant
(1) If the fault notification has been received
technical controller must be notified so that the entries
from a connected subscriber, the controller should check
for both stations coincide. All circuit outages must be
the local subscriber loop to determine the serviceability
recorded on the appropriate station logs, regardless of
of the subscriber terminal equipment and of the
the duration of the outages time or the cause of the
transmission facilities between the subscriber and the
fault. Specific instructions for reporting of stations are
station.  If it is found to be unserviceable, he should
contained in Standard Operating Procedures. Trouble
notify station maintenance personnel.
reports (work orders) must be prepared for each
(2) If the subscriber loop is determined to be
equipment or circuit failure. This work order will notify
functional, he should check the serviceability of the in-
maintenance of the faulty or substandard equipment.
station circuit path, including a check made in
Only by-strict adherence to this procedure can proper
conjunction with microwave personnel, of the multiplex
records be maintained. Prompt, efficient repair of faulty
channel modem assigned to the circuit.
If any
equipment often depends upon the completeness and
component is found to be unserviceable, he should
accuracy of the symptoms described on the written work
change cable pairs or request microwave personnel to
restore service.
d. Catastrophic Failure.  Normally, the technical
(3) If the in-station circuit path is determined
controllers keep the CCOC and DCA informed of
to be serviceable, the controller should request that the
anticipated or existing service failures or degraded
technical controller, at the next station where the circuit
conditions which are beyond the local capability to
appears, check the serviceability of the subscriber
restore within a tolerable delay or outage time period. In
circuit within its station.  The fault isolation mission
an exceptional case, a catastrophic failure condition
should be continued, as necessary by coordination with
may be encountered in which the alarm indicator display
other technical controllers until the fault has been
may depict a number of simultaneous alarms or provide
isolated and corrected.
an indication of a second major alarm condition within
the same station before the first alarm has been cleared.
(4) If the malfunction occurred at a distant
In these cases, the SOC may provide alternate routing
station or between station, he directs and assists the
instructions, or other solutions, as applicable.
distant technical controller in the restoration of the
circuit, as requested.
c. Multichannel.  When it is determined that an
3-11. Fault Isolation Procedures
entire group of 12 channels or supergroup of 60
a. General. The technical controller must keep in
channels  is  unserviceable,  the  station  technical
mind that the fault isolation procedures which follow
controller should take the following action:
serve only as a guide for efficient technical control
operations and do not represent a rigid sequence of
(1) In conjunction with the station microwave
steps which must be followed to solve a problem. The
personnel, he should check the serviceability of the
site SOP should be adhered to if not in agreement with
station multiplex terminal equipment associated with the
the following.  The technical controller is urged to
affected circuits.  If any component is found to be
bypass any unnecessary steps in order to achieve the
defective, he should restore service in accordance with
most expeditious fault location and service restoration.
the service restoration guidelines (SOP). In the event
When an equipment alarm is activated, a fault notice is
that a spare group or supergroup is not available to
received from a user, or routine checks indicate that a
correct the deficiency

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