FUNCTIONAL AREAS

TM 11-5895-1012-10

ports. The Operations Center coordinates the tests,

der to isolate the fault(s) to specific areas and/or equip-

collects and analyzes the results, and directs remedial

actions as necessary.

(3) Unless there are definite indications of a major

abnormality the Operations Center normally does not

take immediate action to inquire about circuit condi-

tivate the supervisory alarms, and consist

tions, inasmuch as continuous inquiries by the Center

noise bursts in the circuit data error rates,

impedes the troubleshooting and fault correction ac-

channel levels. Usually, these problems are brought to

tions of the station Technical Controller and mainte-

the attention of the Technical Controller by the user.

nance personnel. The Operational Center is responsible,

The Technical Controller performs monitoring and

however, for investigating outages which have not

testing routinely, as circumstances permit. However,

been cleared after a reasonable period of time, or if no

when notified of degrading circuit conditions by the

explanation has been made by the remote stations or

user, other Technical Controllers, or maintenance per-

the cognizant master station, and for rendering assis-

sonnel, monitoring and testing of the degraded circuit

tance in restoring service.

e. Maintenance Personnel. After faults have been

located and identified, maintenance personnel are re-

sponsible for effecting necessary repairs and mainte-

in the Technical Control areas, provide a means of se-

nance in accordance with appropriate technical man-

quential access to circuits and groups between most of

uals pertinent to the particular item of faulty equip

the major equipment in the station.

ment.

b. Service Restoration. The Technical

must use every means at his disposal to

4-26. F u n c t i o n a l A r e a s

rupted service as expeditiously as possible. These

a. For purposes of fault isolation, a Technical Con-

means, when available, should be used in the following

trol Facility will fall into one of the following three

order of priority:

functional areas:

(1) If a spare channel is available, the Technical

(1) A Technical Control Facility which provides

Controller should patch the user circuit or group into a

the user with access to the Defense Communications

spare, while isolating and correcting the defective

System; i.e., the serving TCF.

equipment.

(2) A TCF which has voice frequency channel

(2) If a fault is identified within an item of equip

ment for which a standby or spare is available, the sub

breakout, but does not provide the user a direct access

to the DCS; i.e., a receive channel of one group is cross-

stitute equipment should be used to restore disrupted

connected to the send channel of another group..

service while the defective equipment is being re-

(3) A TCF in which the signals appear at a group

stored.

(3) During prolonged, or projected extended out-

or supergroup level, i.e., no vf channel breakout.

b. It is possible that a Technical Control Facility

ages, the Technical Controller should request alternate

routing instructions. Rerouting or pre-empting is ob-

could be involved in more than one functional area at

tained from a list in the station SOP.

one time, depending upon the circumstances at that

(4) As a last resort, the Technical Controller

particular time and station configuration.

should pre-empt lower priority circuits in order to re-

4-27. Troubleshooting Practices

store service for high priority users. Every circuit, in-

cluding switchboard trunks as well as allocated cir-

a. Fault Notification. Technical Controllers are

cuits, is assigned a priority of restoration which must

alerted to actual, or impending circuit outages by

be adhered to in channel restoration. Establishment of

means of alarm indicator displays, by notification

these priorities is performed on a worldwide basis by

from the user, of circuit deterioration or failure by a

the Defense Communications Agency.

distant Technical Controller, and as the result of test

C. Records and Reports. The Technical Controller

ing and monitoring.

who first determines that a fault exists or to whom a

(1) The supervisory alarm subsystems provide an

fault is reported by a user, is responsible for coordinat-

alarm when a failure occurs in various equipment and

ing the fault-isolation activities with distant station

systems at the DCS Station, such as single frequency

Technical Controllers, and is responsible for appro-

signaling equipment, ringers, multiplex systems, fuse

priate log entries and reports. When a fault has been

panels, or the dc power system. When alerted to an ab-

isolated, an explanation of the nature of the trouble

normal condition by an alarm, the Technical Control-

must be entered in the reporting station log, and the

ler and maintenance personnel must perform syste-

distant Technical Controller must be notified so that

matic step-by-step monitoring, or testing of the system

the entries for both stations coincide. All circuit out

segments into, through, and out of the station, in or

4-16