In the asynchronous mode

TM 11-5820-695-35

the cable is half-baud; this signal is converted to full

Mnemonic

Meaning

baud for radio transmission (fig. 5-32, waveforms B and

CTFL............................ Cable-to-radio traffic failure

CVC∅I ......................... Cable voltage controlled os-

E). In the radio-to-cable direction, the signal from

Receiver, Radio R-1467(P)/GRC-144(V) is full baud;

cillator modulation

this signal is converted to half-baud for cable

DCSPCM ..................... Cable sliced pcm data

transmission (fig. 5-38, waveform A and D).

DP ............................... Data pulse

FP ................................ Phase pulse

(3.1) In the asynchronous mode, Radio Set

FRCX ........................... Pcm/orderwire/dc

FRCX∅W..................... Orderwire/dc

AN/GRC-144 transmits and receives information in a

48-channel or 96-channel pulse code modulation

FRPCM ........................ Pcm/orderwire

system. In this mode the "to cable" (TOCX) and "from

FRFAIL ........................ From radio pcm failure

cable" (FRCX) signals are similar to the corresponding

MARY .......................... MAJOR ALARM SUMMARY

signals in the synchronous mode, except that bipolar

N2304 .......................... 2304 KHz Cable-to-radio clock

signal coding at a bit rate of 4.9152 MHz (1 baud is

NCLK ........................... Narrow clock (CTIM inverted)

N∅R ............................ To cable signal normal

203.45 nanosec) is used for the pcm component of the

signal. The cable signals (TOCX and FRCX) are

Np ................................ Negative pulse

∅W .............................. Orderwire

transmitted at the same pulse width and pulse rate for

∅WI ............................. Orderwire In

both 48-channel and 96-channel data rates When

operating at the 96-channel data rate, a 1/2-baud pulse

PP................................ Positive pulse

is transmitted for each binary 1 and succeeding pulses

R2304 .......................... 2304 kHz radio-to-cable clock

are alternately positive and negative (bipolar); when

R4608 .......................... 4608 kHz radio-to-cable clock

operating at the 48-channel rate, two 1/2-baud bipolar

RCFAIL ........................ Radio comparator failure

pulses (one of each polarity) are transmitted for each

RFFL............................ Radio-to-cable functional failure

binary 1. No pulses are transmitted for binary 0. The

RPCM .......................... Retimed pcm

waveforms for the asynchronous mode pcm signals are

RPFAIL ........................ Radio digital processor failure

illustrated in figure 2-1.1. The "to radio" (TRPCM) and

RRIFAIL ....................... Radio receiver interface failure

"from radio" (FRPCM) signals are similar for both

RRM ............................ Radio repeater mode

RR∅W ......................... Radio recovered orderwire

synchronous and asynchronous modes of operation;

they are full baud binary and are transmitted at either

RRPCM........................ Radio repeater pcm

the 48- or 96-channel data rate, as selected.

RRPFAIL...................... Radio repeat pcm failure

RSPCM........................ Reshaped pcm

(4) The basic signal mnemonics used in digital

RTFL............................ Radio-to-cable traffic failure

RVC∅I ......................... Radio voltage controlled os-

data modem 1A12 block diagram descriptions are listed

in the following chart As used on the diagrams, and in

cillator modulation

the descriptions the mnemonics have a prefix 1 for logic

TC1.............................. Test control 1-not used

one or 0 for logic zero to indicate the active logic state

TC2.............................. Test control 2-not used

of the signal at the point The mnemonics listed in the

T4608 .......................... 4608 kHz cable-to-radio clock

chart do not have the prefix 1 or 0, as the basic meaning

TEST ........................... Not in cable-loopback-mode

T∅CX........................... To cable

of the mnemonic Is the same for either prefix. Thus,

1RRIFAIL (output pin 10, fig. 5-36) means that logic

TRPCM ........................ To radio pcm

one at this point indicates a radio receiver interface

XCPCM ........................ Cable traffic

failure. ONOR (output pin F, fig. 5-38) means that logic

zero at this point indicates a radio traffic failure.

(5) Digital data modem 1A12 contains plug-in

components listed in paragraph 2-4a and associated

Mnemonic

Meaning

chassis-mounted connectors and components.

For

BP................................ Full baud data pulse

synchronous operation, plug-in components 1A12A1,

BP∅W ......................... Bypass orderwire

1A12A2, and 1A12A3 are used exclusively m the cable-

CCEX∅W .................... Cable extracted orderwire

to-radio function; plug-in components 1A12A7, 1A12A8,

CCFAIL ........................ Cable comparator failure

1A12A9, 1A12A10 and 1A12A11 are used exclusively in

CC∅WIN ..................... Cable orderwire in

the radio-to-cable function Plug-in components 1A12A4,

CCR∅W ...................... Cable receive orderwire

1A12A5, and 1A12A6 provide circuits for both functions.

CCT∅.......................... Cable transmit orderwire.

These statements apply also to asynchronous operation

CFFL............................ Cable-to-radio functional failure

with the corresponding asynchronous reference

CLPCM ........................ Cable loopback pcm

designations used. Subparagraphs b and c below

CP ............................... Clock pulse

describe the main signal paths in digital data modem

CRFAIL ........................ Cable regenerator failure

1A12. Functional block diagram descriptions of the

CRLFAIL ...................... Cable-to-radio logic failure

cable-to-radio and radio-to-cable circuits of digital data

CSPCM........................ Cable sliced pcm

Change 6 2-8.1