FRONT PANEL BLOCK DIAGRAM DISCUSSION-CONT.

T.O. 31W2-2GSC24-2

TM 11-5805-688-14-1

NAVELEX 0967-LP-545-3010

detected.

The TEMPERATURE indicator in the

when an overheating condition occurs in the power

ALARMS group lights when an overtemperature

supply. When the signal is applied to the thermal control

condition is detected in the power supply.

Three

circuit inhibit power supply signal IPSE is generated to

switches in the TEST CONTROL group and the POWER

turn off the power supply. At the same time, the thermal

CONTROL switch are also mounted on the front panel.

control circuit generates a lamp enable signal that lights

the TEMPERATURE indicator on the front panel and

5-156. When the POWER CONTROL switch is set to

generates remote temperature signals (TEMPC1/C2)

ON, ac power is applied to the power supply and to the

that are applied to the rear panel.

blower fan in the multiplexer set.

The POWER

CONTROL ON indicator lights when the power supply is

5-160. When the LAMP TEST switch is pressed during

on. The incoming ac power is applied through a circuit

normal operation, all the indicators on the front panel

breaker and the POWER CONTROL switch.

light. The lamp test function does not affect the

operation of the functional circuits in the multiplexer set.

5-157. High-level signals LDCRD, LMOOT, LMCDR,

When the LAMP TEST switch is pressed, lamp test

LDTIM, and LMTIM are the enable signals from the

signal LT is generated and the signal initiates the

display card that light the DEMULTIPLEXER CARD,

following functions:

MULTIPLEXER OUT OF TOL, MULTIPLEXER CARD,

LOSS OF DEMUX TIMING, and LOSS OF MUX TIMING

The POWER SUPPLY indicator lights.

indicators on the front panel as shown in figure 5-10.

The LOSS OF FRAME A and LOSS OF FRAME B

b. The thermal

control

circuit

lights

the

indicators are enabled by signals LLOFA and LLOFB

TEMPERATURE indicator.

from the ERD card. The LINK ERROR RATE indicator is

enabled by signal LLER from the ERD card. The error

c. The two 7-segment decoder/ drivers enable

conditions that the indicators represent are listed in table

the FAULT LOCATION numerical display to show 88.

4-1.

d. The display card generates indicator enable

5-158. The card location of a faulty card is presented on

signals that light the LOSS OF MUX TIMING, LOSS OF

the FAULT LOCATION numerical display on the front

DEMUX

TIMING,

MULTIPLEXER

CARD,

panel. The card address for the faulty card is contained

MULTIPLEXER OUT OF TOL, and DEMULTIPLEXER

in signals TA0 and TA1 that contain the tens count 0, 1,

CARD indicators.

or 2, and signals UAO, UA1, UA2, and UA3 that contain

the units digit that is between 0 and 9. The incoming

e. The ERD card generates indicator enable

card address signals from the display card are applied to

signals that light the LOSS OF FRAME A, LOSS OF

7-segment decoder/driver logic circuits, which produce

FRAME B, and LINK ERROR RATE indicators.

the outputs that enable the appropriate numerical

readout from the units and tens numerical display.

When the LAMP TEST switch is released, all indicators

(except the POWER CONTROL ON indicator) return to

5-159. Overtemperature signal HOT-generated and

their normal off state, assuming that the multiplexer set

applied to the thermal control circuit on the front panel

is in a no-error condition.

5-36