FRONT PANEL BLOCK DIAGRAM DISCUSSION-CONT.

T.O. 31W2-2GSC24-2

TM 11-5805-688-14-1

NAVELEX 0967-LP-545-3010

5-161. When the SELF TEST switch is set to the on

5-162. When the DISPLAY RESET switch is pressed,

(up) position, all the diagnostic circuits on the cards in

error reset switch signal ERSTSW is applied to the ERD

the multiplexer set are placed in an error condition. The

card. The ERD card, in turn, generates error reset

self-test function does not affect the normal operation of

signals ERST, ERST-, DERRS, and DERRS that reset

the functional circuits in the multiplexer set. Self-test

the diagnostic circuits in the multiplexer set to their

switch signal STS is generated and applied to the

normal operating (no error) condition. Assuming that the

thermal control circuit on the front panel and to the ERD

multiplexer set is in a no-error condition, all front panel

card when the SELF TEST switch is set to the on (up)

indicators (except the POWER CONTROL ON indicator)

position. The thermal circuit, in turn, generates the lamp

should be out when the DISPLAY RESET switch is

enable signal that lights the TEMPERATURE indicator.

pressed and released.

The ERD card generates self-test signals ST1and

ST2that are applied to the cards in the multiplexer set to

5-163. The ERD card contains functional demultiplexer

place their diagnostic circuits in an error condition.

circuits as well as system diagnostic circuits as

When all the diagnostic circuits are in the error condition,

described in this paragraph. The ERD card generates

all indicators on the front panel should light. Should one

six of the seven remote alarm signals that are applied to

of the diagnostic circuits being tested malfunction, the

the rear panel, the three indicator enable signals that are

associated front panel indicator will be out to identify the

applied to the front panel, and the self-test and reset

faulty diagnostic circuit. Signal STS is applied to the

signals that are applied to the diagnostic circuits in the

ERD card when the SELF TEST switch is set to the off

multiplexer set. The signals applied to the ERD card in

(down) position. The ERD card, in turn, generates error

the diagnostic function, together with their associated

reset (mux) signals ERST and ERST-, and error reset

output signal functions, are listed below and are shown

(demux) signals DERRS and DERRS that reset the

on the block diagram in figure 5-10.

diagnostic circuits in the multiplexer set to their normal

operating (no error) condition.

Output Signal/Destination

Input Signal

Source

FAIL

Display Card

Remote card failure signal FAILC1/C2 to rear panel

Remote out of tolerance signal OOTC1/C2 to rear panel

LMOOT

Display Card

Remote link error rate signal LERRC1/C2 to rear panel

and link error rate signal LLER to front panel

LERR Internal

5-37