SECTION IV DEMULTIPLEXER CARDS FUNCTIONAL OPERATION

T.O. 31W2-2GSC24-2

TM 11-5805-688-14-1

NAVELEX 0967-LP-545-3010

level error signal from the timing or data diagnostic

5-390. Composite OR Gate and Latch Circuits.

circuits applied to OR gate U19 sets the latch to the error

condition through OR gate U17-6 and AND gate U20-3.

5-391. Latch U20, U23 generates diagnostic reference

timer card error signal MRT when an error is detected or

5-393. When the system is in the self-test mode, self-

when self-test signal ST2is applied to the card. Latch

test signal ST2inhibits AND gate U20-3 to prevent any

U20, U23 is reset by signal ERST from the front panel as

simulated error inputs from OR gate U17-6 from setting

previously described.

latch U20, U23. Signal ST2forces the diagnostic circuits

to generate high-level inputs to AND gate U17-8 when

5-392. The three retriggerable one-shot multivibrators

the card diagnostic circuits are operational. AND gate

(U10-9, U15-6, and U1510) are normally held in

U17, in turn, sets latch U20, U23, thus generating signal

conduction by timing signals T3600A and T4800A and

MRT-. When the SELF TEST switch on the front panel

system clock signal Ro. An error condition (loss of signal)

is set to the off (down) position, signal ST2goes high

to any one of the multivibrators causes the appropriate

(diagnostic enable) and signal ERST resets latch U20,

multivibrator's duty cycle to expire and set latch U20,

U23 to its no error state.

U23 through OR gate U17 and AND gate U20. A high-

SECTION IV

DEMULTIPLEXER CARDS FUNCTIONAL OPERATION

Common Cards

Paragraph

5-394. INTRODUCTION.

Seq card

5-460

5-395. This section contains the block diagram and

GC/DM card

5-463

detailed circuit discussions for each of the card types

OEG card

5-468

used in the demultiplexer. The detailed circuit discussion

FS card

5-472

for each card follows the associated card-level block

ERD card

5-535

diagram discussion. The following cards are described

in this section.

5-396. SMOOTHING BUFFER (SB) CARD.

Channel Cards

Paragraph

5-397. GENERAL. The SB card is a channel option

SB card

5-396

card that may be used to service one data output

NBSB card

5-419

channel with its associated timing. The SB card function

TD card

5-426

is basically the complement of the RCB card function

VD card

5-444

performed in the multiplexer. Functionally, the SB card

demultiplexes one channel of data out of the high-speed

data stream from the far-end multiplexer.

5-103