No. 1 Crossbar and Crossbar Tandem Systems

and and

System System

be be

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the the

be be

better better

Crossbar Crossbar

employed employed

made made

the the

• •

1 1

of of

equipment equipment

in in

could could

appearance appearance

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metal metal

also also

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~_.~ ~_.~

Crossbar Crossbar

originating originating

offered offered

required required

one one

SYSTEMS SYSTEMS

1 1

both both

The The

lines lines

its its

overall overall

senders senders

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system system

pulsinfi pulsinfi

No. No.

subscribers subscribers

for for

gave gave

precious precious

SDR. SDR.

developed developed

Crossbar Crossbar

TERM. TERM.

TANDEM TANDEM

the the

own own

1 1

disadvantages disadvantages

Crossbar Crossbar

this this

times times

1 1

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.._.;;;.._~~==---r-, .._.;;;.._~~==---r-,

was was

of of

system; system;

7 7

using using

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7-1. 7-1.

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frames frames

No. No.

I I

complete complete

that that

revertive revertive

PBX PBX

by by

No. No.

Diagram Diagram

of of

view view

has has the the

CROSSBAR CROSSBAR

to to

System System

7.1 7.1

connections; connections;

and and

Figure Figure

control control

CHAPTER CHAPTER

on on

MKR. MKR.

some some

AND AND

ORIG. ORIG.

Block Block

each each

outgoing outgoing

areas, areas,

completing completing

in in

changes. changes.

expected expected

path path

line line

instance, instance,

SYSTEM SYSTEM

and and

markers markers

OFFICE OFFICE

common common

call call

Crossbar Crossbar

simplified simplified

traffic; traffic;

panel panel

was was

shown shown

a a

For For

1 1

SDR. SDR.

the the

SUBS. SUBS.

A A

overcome overcome

CROSSBAR CROSSBAR

number number

in in

it it

characteristics characteristics

is is

ORIG. ORIG.

equipment equipment

talking talking

1 1

Simplified Simplified

to to

No. No.

also also

CROSSBAR CROSSBAR

incoming incoming

in in

with with

shorter shorter

s_ubscriber s_ubscriber

1 1

NO. NO.

7-1 7-1

is is

Since Since

The The

maintenance. maintenance.

System. System.

without without

largely largely

terminating terminating

both both

NO. NO.

each each

GENERAL GENERAL

Figure Figure

connections. connections.

terminating terminating

arrangement arrangement

transmission transmission

for for System System

function function

to to

and and 7.1 7.1

contacts contacts added added

system system

used used

Panel Panel

possible possible

mid-1930's mid-1930's A. A.

Main Main

Frame Frame

the the

Frame Frame

link link

side side

Crossbar Crossbar

of of

1 1

The The

Frame Frame

R·PTY R·PTY

Frame Frame

classes: classes:

CALL.• CALL.•

Frame Frame

frames. frames.

Frame Frame

Extension Extension Crossbar Crossbar

-Sw.-Vert. -Sw.-Vert.

SYSTEMS SYSTEMS

No. No.

Sender Sender

Group Group

Equipment Equipment

1 1

means means

terminating terminating

Connector Connector

a a

Connector Connector

Frame Frame

Sender Sender

Marker Marker

Link Link

Trunk Trunk

Link Link

(vertical (vertical

for for

Frame Frame

general general

No. No.

(Col. (Col.

Frame Frame

L.D.F. L.D.F.

the the

Frame Frame

TANDEM TANDEM 7-2. 7-2.

crossbar crossbar

provided. provided.

Group Group

two two

to to

Relay Relay

cross-connecting cross-connecting

Link Link

Choice Choice Junctor Junctor

Distributing Distributing

major major

the the number number

Frame Frame Frame Frame

provides provides

also also

Incoming Incoming

Terminating Terminating

Incoming Incoming

Terminating Terminating

circuit circuit

into into

Figure Figure

to to

for for

Connector Connector

SW. SW.

the the M·2. M·2.

Line Line

Block Block

Number Number

Terminating Terminating

Incoming Incoming

Terminating Terminating

CROSSBAR CROSSBAR

frames frames

Connections Connections

are are

in in

M·l M·l

(LDF), (LDF),

7.2 7.2

used used

AND AND

"line" "line"

.5 .5

pairs pairs

PRIMARY PRIMARY

directory directory

link link

divided divided

is is

Frame Frame

VERTICAL VERTICAL

shown shown

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R R

any any

L/NI< L/NI<

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Frames Frames Frame Frame

standpoint standpoint

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line line

cable cable

Link Link

T T

to to

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(MDF) (MDF)

Frame Frame

LINE LINE

Connector Connector

may may

CROSSBAR CROSSBAR

Frame Frame

the the

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1 1

LDF) LDF)

trunk trunk

Group Group

Equipment Equipment

permits permits

Sender Sender

traffic traffic

Frame Frame

H H

NO. NO.

Line Line

Distributing Distributing

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Frame Frame

Link Link

Junctor Junctor

a a

frames frames

side side

assigned assigned

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This This

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7 7 -

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Extension Extension

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From From

v v

to to

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system system

CH. CH.

Line Line

District District Subscriber Subscriber

District District

Originating Originating

Figure Figure

Frame Frame

LDF) LDF)

horizontal horizontal

cross-connecting cross-connecting

Distributing Distributing subscriber subscriber

marker. marker.

The The

Originating Originating

Originating Originating Subscriber Subscriber

Office Office

District District

Line Line dial dial ·- CH. 7 MQ. 1 . CllOSSBAl. AID ' ClOSSIAI. TANDEM SYSTEJIS

The equipeat re~;r.edto coaplete a call aacl. the path of a call th.roulh · . Mo. l Crossbar Sys tea e41,uipaent fraaes is sh·o1101.1J1. F1.gure 7- 3.

-·' t.-=...•=:--.. -· ~-=---· -.. ~--=-·

Pisure 7·3 Major Ro. 1 Crossbar Fraaes

B. PRAMHEQUIPMEHT 1.. Liae Link. The liae link fraae is used for both originating and terauatl.ll.l calls. It coJtD.e.cts the custo•ers liaes • which are assigned. to verticals of the

7.3

of of

ten ten

. .

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per per

as as

the the

abbreviation abbreviation

hour. hour.

SYSTEMS SYSTEMS

0 0

II II

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L.IN£.:S L.IN£.:S

load load

has has

primary primary

traffic traffic

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lines lines

length length

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7-4. 7-4.

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switches switches

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known known

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.. ..

TANDEM TANDEM

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Since Since

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vertical vertical

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junctors junctors lines: lines:

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CROSSBAR CROSSBAR

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Call-Second Call-Second

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. .

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primary primary

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NO. NO.

Figure Figure

added added additional additional

called called horizontal horizontal

for for

horizontal horizontal

ten ten

switches, switches,

used used

single single

connect. connect.

both both

crossbar crossbar

verification verification

horizontal horizontal

line line

lines lines

time time

characteristics, characteristics,

has has for for The The

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going going

primary primary

. .

~~ ~~

7 7 -

No·rc.sr..l No·rc.sr..l

. . CH. CH. CH. 7 - NO. 1 CROSSBARAND CROSSBARTANDEM SYSTEMS

On service orders each line assignment will carry a location number for the line on the line link frame just as it does in the manual office (panel and jack)~in the panel office (line group and terminal), and in the crossbar unit (column, switch, and vertical). For example, 0152 means column 01, switch 5 and vertical 2, illustrated in Figure 7-5.

I I 9 I I I : i i

7 I ,. I I I I I ! i I

II I ~ h7l I ! . I i ,. I I I I ! z I I I I ! I I : I 0 I ! : oo 0/ 02 0.3 0~ OS COL.I./.1'-fAI No

Figure 7-5 Service Order Number 0152.

Each line link frame has associated with it a "control circuit" whose function it is to recognize a calling line, choose an idle line link and assist in the selection of an idle district junctor and to operate the necessary selecting and holding magnets for connecting these paths together. On a terminating call it assists in setting up the call from the incoming trunk over a line junctor and line link to the called line. Since a line link controller circuit may provide service to as many as 690 subscriber's lines, it is of the utmost importance that there is always a controller circuit available. As a service precaution, line link frames are arranged in pairs insofar as their controllers are concerned.

7.5 CH. 7 - NO. 1 CROSSBARAND CROSSBAR TANDEM SYSTEMS

This arrangement is called a "home" and "mate" controller circuit operation. -rr-a call rs- delayed in the "home" controller circuit, it will be transferred automatically to the "mate" controller circuit and handled on an uemergency11 basis. 2. District Junctor The district junctor frame is mounted in the center o£ the "b1strict Frame Group," the sub scriber sender l1rik 1s on the left and the district link frame is on the right. The district junctor frame is used to mount the relay equipment which provides talking battery and supervision for the calling subscriber and controls the operation of the subscriber message register on calls dialed directly by the sub scriber. Each frame will care for the 100 district junctors of the associated district link frame. The subscriber sender link frame provides access to office junctors. The district junctors are multipled to Z, 3, 4, 5, 6, or 7 line link frames as indicated by the traffic requirements. A diagram of connections to a district junctor is shown in Figure 7-6.

liNC LINX rR. 4Et:. I"A I. . lr; /J/.ST: 1../AIK r,#£'. jv4U., I. .sec. H•N Pill' o'-Sr. JCr. .5U8 S£ND.. /..K. sec. I" AI. r V·H

"NilE

V·H

Figure 7-6 Connections Provided by a District Junctor.

7.6 a

cut

call

use

can

each

this

with frame

by can is

whose

the

to control

begins

which

calls

the

are the

for

circuit.

coins junctors

primary frames.

each each

party

located at

each

primary

This used

SYSTEMS for

registration

swit~hes.

link

determines equipped Since

area.

ten

for for

marker

circuits

link

horizontals

the

junctor switches, junctor

point is

are

verticals. switches

subscriber

refund

control

zone

called

line

switches also frame. across

provided

use

conjunction

the

relays,

access

secondary subscriber

subscriber a

TANDEM

200

call. frame.

charges

uses It

originate

11th idle is

zone

in the

frame for

the

junctor

secondary frame, link

the with the and The

selected

ten

switches,

district horizontals

an gain

with

crossbar

and link

district

not also

originating

given

of secondary

link

are Frame

which

collect

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the

secondary

a call.

CROSSBAR

charge

continuous the

point

circuit

with

lOth

the

assists

and sender

one before

7.7

primary

junctors,

additional

district terminate

the

frame

relays.

district

for primary connect available

Link sender

AND

200

are

provided

the

any

marker

local

conjunction

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senders

Frame

the

district

are

particular

c:trcu:tt,

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junctors,

whether

link

make

Further, to

control

outgoing

before

to equipped

circuit

pr:tmary

the

function

call. of

it Sender selecting

arrangement the junctors

Noncoin

frames,

the

district

Link and

Those

selected and subscriber

CROSSBAR

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top

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link

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coin

district

district switch.

originating

control

subscriber

been

arranged

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the emergency

dial,

NO.

coin

depending

(split) answers. The equipment

outside line District frame

The the the be secondary In

switches switch. links The at

per connected, switches, function to sender circuit frame consists primary with Subscriber used be particular

by has An The which

The with

7 -

CH.

is is

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many many

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of of

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link link

units. units.

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be be

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sub

trunks trunks

ten ten

a a

be be

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two two

. . on on

on on

each each

trunk trunk

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cable, cable,

of of

bay bay an an

any any

switches. switches.

10 10

~o ~o

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to to

type. type.

handle handle

200 200

must must

occurs occurs

secondary secondary the the

The The

or or

of of

SYSTEMS SYSTEMS

frame. frame.

frames frames

for for

above above and and

frames. frames.

trunk trunk

on on

units units

vertical vertical

district district

can can

exceeds exceeds

call call

over over

pairs, pairs,

horizontals horizontals

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exchange exchange

distributing distributing

unit unit

point point

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link link

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frame frame

originate originate

manually manually

fr.ames. fr.ames.

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areas. areas.

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a a

TANDEM TANDEM

link link

originating originating secondary secondary

cons1st cons1st

office office

200 200

100 100 frame frame

of of

more more

condition condition

appear appear

main main

connection connection

switch switch

of of

frames frames

given given

link link

switch switch

possible possible

switches. switches.

junctors junctors

directly directly

pair, pair,

used used

cross-connected cross-connected

ten ten

vertical vertical

or or

office office

a a

(20 (20

right) right)

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completed completed

the the

it it

link link

office office

underground underground

be be

means means

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to to

exchange exchange

trunks). trunks).

the the

which which

and and

of of

extension extension

be be

to to

obtain obtain

and and

operate operate

office office

trouble trouble

of of

or or

office office

junctors, junctors,

cabinet. cabinet.

each) each)

by by

of of

always always

can can

primary primary

on on

consists consists

primary primary

located located

Frames Frames

second second

a a

7.8 7.8

200 200

to to

secondary secondary

makes makes

are are

verticals verticals district district

to to

AND-CROSSBAR AND-CROSSBAR

of of

sender sender

will will

the the

if if

trunks trunks

pair pair are are

(left (left

locations locations

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they they

cabled cabled

local local

various various

trunks, trunks,

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100 100

frames, frames,

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of of

frame frame

office office

switches switches

Frame Frame

frames frames

Extension Extension

frames frames

a a

times times

senders senders

on on

switch switch

of of

number number

that that

to to

that that

the the

are are

junctor junctor

switches switches

office office

to to

trunk trunk

Here Here

l1nks l1nks

terminate terminate

switches switches

controller controller

CROSSBAR CROSSBAR

Extension Extension

the the

frames frames

link link

(10 (10

Link Link

link link

desirable desirable

1 1

the the

arrangement arrangement

office office

subscriber subscriber

pair pair

of of

outgoing outgoing

the the

hundred hundred

primary primary

is is

reach reach

4000 4000

maximum maximum NO. NO.

it it

per per

provided. provided.

When When

central central

available available

Office Office

insures, insures,

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one one

required required to to

jumpers jumpers

frame. frame.

Office Office

switches switches

terminate terminate

district district

as as

This This

horizontals horizontals

extensions extensions

The The

office office ten ten frames, frames,

office office

secondary secondary hundred hundred

Two Two

Each Each regular regular

a a senders. senders. All All groups groups

operated operated

Office Office Each Each

sender sender

. .

7 7 -

6. 6.

5. 5. CH. CH. a

basis.

trunk

that

call

sub or

manual

each trunk.

The

paths

switches

func senders.

the

informa

to distant

eight

will

it two

control system

normally

the

formerly

pulsing

the

SYSTEMS

in originating

regular

five

same of

except

maximum

point

giving

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frame.

at selects

combined.

office, frame a

panel origination

Calls

links.

the

outgoing

which

the

frames

200

receives

to In

offices

TANDEM

crossbar

indicator

also

the

mounts

maximum

wh1ch

group.

revertive

use

serve senders. system,

minimum

manner with

ten

office

much

the

a a

sender

distant

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information

all

multipled

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the

setting

connector or

frame

selections adjacent a to of circuit

same

senders

will

each

crossbar

marker

operation. panel

CROSSBAR

are

sender

senders.

adjacent

line the

bay

remains

final on

7.9

two

the

perform

Connector

the The

and

connectors

or AND returns

crossbar

subscriber

markers. marker

require

sender of in

and

marker

access

of a circuit

senders

and keypulsing

senders, entire

will

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connected

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circuits

three control to calling control end.

keypulsing handled panel Marker

Marker

group controlling

the Sender

eight

and

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installed

switches

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subscriber

basis

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to terminating

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link

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case

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location

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subscriber originating connector up

ten originating

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the

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NO.

trunk

terminating tion

additional they secondary office decodes tions

sender which ten

Subscriber offices announcer Originating are offices distant selector

Each accommodate make between selections The of scriber subscriber sender The maximum These The handled Originating Each Each

markers.

7 -

CH.

bay bay

as as

the the

be be

is is

to to

maximum maximum

common common

calls calls

class class

trunk trunk

A A

additional additional

first first

a a

relay relay

a a

may may

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of of

path path

subgroups subgroups

12 12

signal. signal.

originating originating

100 100

a a

multi-

possible possible

hour hour

for for

SYSTEMS SYSTEMS

bays bays

have have

or or

traffic traffic

with with

route route

the the

(50 (50

for for

relays. relays.

6 6

subgroups. subgroups.

802 802

operator operator

a a

selected selected

choice choice

subdivided subdivided

busy busy

maximum maximum

selection, selection,

not not

originating originating

of of

for for

information information

provided. provided.

4, 4,

A A

TANDEM TANDEM

for for

one one

the the

care care

are are

permanent permanent

arranged arranged

be be

above. above.

route route

with with

3, 3,

may may

the the

relays relays

first first common common

common common

first first

to to

establishes establishes

offiee offiee

and and

party party

to to

or or

2, 2,

4 4

3 3

2 2

of of and and

associated associated

talking talking are are

may may

will will

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frames. frames.

required required

group. group.

and and

Supplementary Supplementary

with with

groups groups

be be

and and

route route

CROSSBAR CROSSBAR

may may

capacity capacity

7.10 7.10

calls. calls.

with with

zero zero

with with

limitations limitations

equipped equipped

a a

group group

junctor junctor

which which

classes classes

may may

100 100

AND AND

markers markers is is

addition addition

trunk trunk

capacity capacity

and and

marker marker

office office

of of

relays relays

relay. relay.

has has

district district

markers markers

per per

groups groups

subgroups subgroups

originating originating

for for

in in

groups groups

relays). relays).

ZO ZO

of of

transmitting transmitting

per per

when when

relays. relays.

noncharge, noncharge,

each each

including including

the the

keypulsing keypulsing

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markers markers

district district

marker marker

route route

follows: follows:

of of

as as

CROSSBAR CROSSBAR

trunk trunk

maximum maximum

marker marker

desired desired

or or

choice choice trunk trunk

2 2

trunk trunk

2 2

trunk trunk

1 1

features features

on on

of of

subscriber subscriber

markers markers

1 1

the the

3 3

number number

originating originating

route route

added added

contact contact

arranged arranged

Each Each

subgroup subgroup

All All

30 30

follows: follows:

codes codes

The The marker marker

The The

24 24

the the service service

well well

few few

NO. NO.

c. c.

b. b.

a. a.

plus plus

markers markers

based based

A A

eight eight

group group

The The of of

as as of of maximum maximum

charge charge

from from

to to district district

The The

7 7 - CH. CH. to

for

will

the

as a

With

the

trunk

frame

trunks,

of called case

frame.

the

incoming

sender

extra

which

party,

10.

group,

type.

busy trunks,

additional

each

ring

the

100

known

SYSTEMS

the

location

circuit)

mounts

right

equipped

to removal these

connect

provided

100

and

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TANDEM TANDEM

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Connector Connector

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mount mount

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for for

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7.12 7.12

sender, sender,

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work work

incoming incoming

sender sender

link link

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the the

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horizontal horizontal

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to to

relays relays

switch switch

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circuits circuits

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mount mount

the the

vertical vertical

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sender sender

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only only

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called called

information information mount mount

marker. marker.

keypulse keypulse

from from

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switches switches equipment. equipment.

incoming incoming

idle idle

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right right

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Each Each

Multicontact Multicontact

7 7 -

15. 15.

14. 14.

13. 13. CH. CH. CH. 7 - NO. 1 CROSSBARAND CROSSBAR TANDEM SYSTEMS

Each connector frame will care for four marker connector circuits, associated control and alarm relay equipment common to these circuits, together with a location at the top of the frame for a maximum of two "B" position finder units, required when the office unit is served by a local "B" switchboard. One connector circuit will consist of from 7 to 15 multicontact relays. The number varies with the number of terminating markers and the number of senders associated with connector. 16. Terminating Marker The terminating marker frame is used to register the called number it receives from the terminating sender and from the translation of that number, locate and test the called line, and control the selection and closure of a path from the incoming trunk through the incoming link and line frames to the called line. · The number of terminating markers provided in an office will vary from two to ten, depending on the total number of terminating busy hour calls the markers will be required to handle. When a marker is seized by a sender, it must determine, from the number that has been dialed, the correct number group connector to operate, and also the correct 100 block and 20 block relays to operate in the number group. This process is known as decoding, because the decimal directory number received, must be translated in terms designating .a number group, a 500 group relay, a 100 block relay, and a 20 block relay. The marker can be arranged to test twenty lines at one time. 17. Number Group Connector Circuit The 10,000 numbers in a given office are divided into "number groups." A.number_group consists of a ser~esof numbers ~ntowh1ch all the terminating markers have access, but only one at a time. The size of a number group depends upon the amount of terminating traffic

7.13

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7 7 -

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7.15 7.15

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7 7 -

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7.18 7.18

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7 7 - CH. CH.

is is

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Figure Figure

The The This This

7 7 - CH. CH. CH. 7 - NO. 1 CROSSBARAND CROSSBARTANDEM SYSTEMS

choice., on which one of the four line link frames of the choice and in which horizontal group of the line link frame the called line is located.

LINE JUNCTOR

LINE LINK

INTER~OFFICE TRUNK ~-.._,.~

--TERMiNATiN&--l SENPER-I,.INK FRAME I SENOER LINK

Figure 7-8 Terminating Call in a No. 1 Crossbar Office

From the line location information, the marker, by way of a line choice connector and line junctor connector, is able to test the line links that serve the horizontal group in which the called line is located. Knowing the incoming link frame to which it must connect, the marker tests the line junctors between this frame and the line link frame. At the incoming link frame, connector relays give the marker access to the links available to serve the incoming trunk. From this combination of links and junctors, the marker selects an idle incoming link with access to an idle line

7.21

it it

· ·

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7-9 7-9

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7.22 7.22

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CH. CH.

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7.24 7.24

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7 7 -

26. 26.

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7.25 7.25

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7.26 7.26

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mes~age mes~age

every every

with with

trunk trunk

tandem tandem

it it

7 7 -

junctor junctor

7-12 7-12

SYSTBM SYSTBM The The

c. c.

information information

Crossbar Crossbar

over over

frame. frame.

is, is,

1 1

upper upper

CH. CH.

THE THE

link link

other other

incoming incoming

outgoing outgoing

incoming incoming

operation operation

the the

office office

Figure Figure

crossbar crossbar

that that

No. No.

wires wires B. B. CH. 7 - NO. 1 CROSSBARAND CROSSBARTANDEM SYSTEMS

through a marker connector frame. The marker receives information from the sender and supplies the sender with information it needs to complete .the call. The marker selects an outgoing trunk to the desired destination and connects the incoming trunk through the trunk and office link frames to the outgoing trunk. -

OPERATOR

~'6~~~~6'OP, MF WITH 01AL5 OR MF KEY5ET5

OPE:RATOH POS!T!ONS ~QUIPP

In the simplified block diagram of Figure 7-13 the switching network of the system consists of crossbar link frames. Incoming trunks from the calling central offices appear on trunk link frames and outgoing trunks to the called central offices appear on office link frames. Through a system of links and junctors, which interconnect the crossbar switches on these frames , any incoming trunk can be connected to any outgoing trunk. For each connec-

7.27

7.28 7.28

Figure Figure 7-12 7-12 Block Block Diagram Diagram \.Jith \.Jith and and Without Without MiA MiA

L-__ L-__

:ONNECTOR :ONNECTOR

::LiNG ::LiNG INOEiER INOEiER il il

INDEXER INDEXER --<>-<>- RECORDER RECORDER

BI--LING BI--LING

TRANSVERTER TRANSVERTER ~ONNECTOr--

I I TAANSV(RTER TAANSV(RTER INDEXER INDEXER

~ ~ CALL CALL IOENTITY IOENTITY

NUMBER NUMBER MATCHING MATCHING

TIMING TIMING

l.INE l.INE OBSERVING OBSERVING

MASTER MASTER PULS) PULS)

OR OR MF MF

(OC (OC

sweo sweo

AMA AMA

CONTRv~w.Le."' CONTRv~w.Le."' CAMA CAMA POS POS CKT CKT

(DC (DC PULS} PULS} OR OR MF MF

POS POS El El TEL TEL CI

AUTOMATIC AUTOMATIC TEST TEST

L-----{O""ECTOr--

eo eo

CAMA CAMA POS POS CKT CKT

TRUNK TRUNK

DSA DSA (OC (OC

PULS) PULS) OR OR MF MF

fRK fRK

AUTO AUTO TEST TEST

OR OR

I I - SW8D SW8D IN IN SAME SAME BLDG BLDG

TOLL TOLL

WITH WITH OR OR OSA OSA TOLL TOLL

POS POS CK CK rUI'f rUI'f u::n::. u::n::. - -- 1 1

. . --<>--<>-

WAITING WAITING ---.-~ ---.-~

CONTROLLER CONTROLLER -tr:

1-;-;==::::-:~:;::!:;:;;-L 1-;-;==::::-:~:;::!:;:;;-L CONNECTOR CONNECTOR I I ......

I I

SODER~~ SODER~~

y y

+ + ~- I I

~itftj'TQ ~itftj'TQ t===~~ t===~~

TO TO CAMA CAMA POSITION POSITION

INCOMING INCOMING TRUNK TRUNK PRETRANSLATOR PRETRANSLATOR

POS POS LK LK IMF IMF PUL$1 PUL$1 I I

I I REMOTE REMOTE "''P'EiiiTION "''P'EiiiTION

I I I I I I ONLY~______, ONLY~______,

A8M A8M

l------·---+t-H------+------·~!!!..- AOOITIONAL AOOITIONAL FOR FOR AMA AMA

:::r- : : ,, ,, T T

SE:E SE:E

NOTE NOTE

WI~~~T WI~~~T

I I 1~;.'i_~UECY 1~;.'i_~UECY

I I MUL~r;,~fv~~ECY MUL~r;,~fv~~ECY

o:MA o:MA

[MUL [MUL SENDER SENDER TEST TEST CONNECTOR CONNECTOR

RECORtiRI RECORtiRI TAOUBL£8 TAOUBL£8

I I

f-+>-

TRANSI.,ATOR TRANSI.,ATOR I

MARKER MARKER

FOREIGN FOREIGN AREA AREA

ABM ABM

ONLY--

TRUNK TRUNK TEST TEST

I I

OUTGOING OUTGOING a : :

r r .. .. , , .. .. ., ., 1 1

1-:___=_±:=t:::t----,-- OR:Jj:~fe~NG-j OR:Jj:~fe~NG-j TRUNK TRUNK ~~~~~~~~ ~~~~~~~~

INCOMING INCOMING f'ROM f'ROM

GROUPING GROUPING

JUNCTOR JUNCTOR

OFFICE OFFICE

TRUNI'. TRUNI'. \,.INK \,.INK

I I

!QUIPIIENT !QUIPIIENT

JNT£RTOLL JNT£RTOLL TRUNk TRUNk

OFFtC£ OFFtC£ THRIJ THRIJ TOLL TOLL

2 2 WAY WAY

TO TO OR OR FROM FROM ANOTH£1 ANOTH£1

- 7 CH, CH, NO, NO, 1 1 CROSSBAR CROSSBAR AND AND CROSSBAR CROSSBAR TAI,DEH TAI,DEH SYSTE:"fS SYSTE:"fS

a a

of of

for for

equip

outgoing outgoing

tandem tandem

paths paths

(sender (sender

connecting connecting

control control

trunk trunk

the the

releases, releases,

calls calls

This This

SYSTEMS SYSTEMS

functions functions

of of

service service

senders, senders,

(senders, (senders,

these these

and and

channels) channels)

set set

trunk trunk

crossbar crossbar

of of

into into

basic basic

TANDEM TANDEM

LINK LINK

received received

outgoing outgoing

switching switching

of of

(or (or

trunk trunk

one one

functions, functions,

The The

CONNECTOR CONNECTOR

OFFICE OFFICE

are are

equipment. equipment.

elements elements

equipment: equipment:

idle idle

into into

called called

matching matching

its its

incoming incoming

of of

paths paths

call, call,

CROSSBAR CROSSBAR

a a

an an function). function).

they they

is is

are: are:

diagram diagram

call. call.

a a

incoming incoming

the the

7.29 7.29

as as

control control

AND AND

digits digits

control control

on on

number number

the the function). function).

block block

which which

select select

performs performs

possible possible

(marker (marker

path, path,

LINK LINK

elements elements

another another

of of

CIRCUIT CIRCUIT

and, and,

etc. etc.

these these

digits digits

common common

a a

and and

samll samll

common common

function). function).

CROSSBAR CROSSBAR

time, time,

a a

SENDER SENDER

(marker (marker

between between

the the

each each

CONTROL CONTROL

1 1

for for

serve serve

the the

several several

of of

frames frames

control control

of of

Simplified Simplified

to to

by by

NO. NO.

short short

are are

(marker (marker

links links trunk trunk

information information

Test Test

Translate Translate Store Store function). function).

establish establish

etc.), etc.),

connectors, connectors,

7-13 7-13

these these

7 7 -

4. 4. 2. 2.

3. 3.

free free 1. 1.

To To

corr~on corr~on

consists consists

there there

is is

services services

CH. CH.

selected selected

Figure Figure

these these

and and relatively relatively

the the

markers, markers,

ment ment

is is

through through

tion tion markers, markers,

are are

in in

the the

from from

For For

Trunk Trunk

of of

wh1le wh1le

for for

~or ~or

and and

consists consists

in in

of of

a:e a:e

metal metal

frame. frame.

depicts depicts

lengths. lengths. and and

used used capacity, capacity, a a

off1ce off1ce

etc., etc.,

note note

to to

its its

circuit circuit

outgoing outgoing

which which

(bas1c (bas1c

as as

on on

performing performing

7-14 7-14

used used

frames frames

important. important.

often often first first

plan plan

SYSTEMS SYSTEMS

crossbar crossbar

to to

inductors, inductors,

illustrations illustrations

large large

links links

and and

link link

7-19 7-19

Link Link system. system.

sheet sheet

how how

is is

text text

frame frame

objective objective

such such

4,000 4,000

in in

are are since since

drilled drilled

sizes. sizes.

traffic traffic assembled assembled

primarily; primarily;

few few varying varying

panels panels

trunks trunks

the the

l1nks l1nks

than than

trunks, trunks,

of_switches of_switches

Figure Figure

that that

system system

satisfactory satisfactory

a a

mounted mounted

with with

TANDEM TANDEM

tandem, tandem,

this this

Trunk Trunk

function). function).

and and

of of

trunks trunks

of of

Figure Figure

are are

accommodate accommodate

equipment equipment

etc. etc.

200 200

in in

a a

group group

fuse fuse

system system

switching switching

the the

in in are are

bays bays

7-12 7-12

other other

speed, speed, of of

resistors, resistors, are are

high high

worthwhile worthwhile

can can

effected effected

of of

switching switching

ends ends

equipment equipment

adequate, adequate,

switches switches turn turn

in in highly highly

use use

visualizing visualizing own own

precisely precisely

incoming incoming

trunks trunks

is is

markers, markers,

while while

(sender (sender shown shown

it it

~e ~e

shows shows

tubes, tubes,

and and

of of

Nomenclature Nomenclature CROSSBAR CROSSBAR

tandem tandem

type type

in in crossbar crossbar be be

in in

on on

or or

7.30 7.30

incoming incoming

all all It It

160 160

to to

original original

Figure Figure

range range

inches inches

finally finally

a a

to to

In In

their their and and

relays, relays,

nevertheless nevertheless

AND AND

of of

compr1s1ng compr1s1ng

7-14 7-14

elements elements

type type

6 6

aid aid

practical practical

wide wide

frame frame

second?rr second?rr

primary primary

control control

top. top.

are are

to to

sw1tch1ng sw1tch1ng

Frames Frames

and and

crossbar crossbar

function function

and and

as as

which which

this this

i~coming i~coming

senders, senders,

to to

w1de w1de

serve serve

required required

not not purpose purpose electron electron

have have

The The

and and

~ts ~ts

Frame. Frame.

fast, fast,

a a

the the

feet feet

Framework Framework

each each

position position

link link

proved proved

to to

as as

Figure Figure

inches inches tandem, tandem,

given given

is is

bars bars

such such

•. •.

fundamental fundamental

circuit circuit

economies. economies.

its its

1n 1n 11 11

on on

CROSSBAR CROSSBAR

in in

units units

3!000 3!000

are are

housing housing

and and

equipment equipment

Link Link

figures figures

contain contain

has has

years, years,

10 10

1 1

uprights. uprights. it it

frames frames

Extension Extension

trunk trunk

Marker Marker

name name

provided provided

primary primary

~lex1b1l1ty ~lex1b1l1ty

area~ area~

the the

fi:st fi:st

specialized specialized

NO. NO.

junctors. junctors.

arranged arranged

interconnection interconnection

relay relay

of of

types types

The The controllers, controllers,

the the contain contain

Trunk Trunk

these these

switches. switches.

frames frames

reveals reveals

example, example, Outpulse Outpulse

a a

Link Link

frame frame

crossbar crossbar

illustrate illustrate are are capacitors, capacitors,

bases bases

mounted mounted

measure measure

The The elements elements

Since Since various various Frames Frames

mounted mounted

Most Most

mounting mounting

tandem tandem

trunk1ng trunk1ng

the the

7 7 -

c1rcu1ts c1rcu1ts

of_about of_about

2. 2.

5. 5.

Over Over

1. 1.

ass1gnable ass1gnable

CH. CH.

trunk~ng trunk~ng

crossbar crossbar

con~rol con~rol and and

enabl1ng_ enabl1ng_ trunks trunks

max1mum max1mum

meeti~g meeti~g metropol1~an metropol1~an

aLP aLP

POINT POINT

PANEL PANEL

TS TS

SWITCHES SWITCHES

KEY KEY

RELAYS RELAYS

C C

NO NO

DESIGNATION DESIGNATION

STRIPS STRIPS

JK JK

TS TS

PANELS PANELS

USE USE

200 200

3W 3W

A A

F F

t--M t--M

Frames Frames

I I

0 0

3 3

2 2

! !

7 7 ~ ~

I I

4 4 6 6

9 9

B B

!!; !!;

i i

-=~----~·1 -=~----~·1

9 9

j[ j[

~ ~

5 5

SYSTEMS SYSTEMS

E E

BAY BAY

I= I=

5 5

o~ o~

() ()

o~ o~

0 0

JC JC

LC LC

l l

9 9

5 5

Extension Extension

I I

SECONDARY SECONDARY

~ ~

I~ I~

=--=2=·-a=r=_ =--=2=·-a=r=_ TANDEM TANDEM

D D

() ()

1L=r 1L=r

0 0

OL~ OL~

oc oc

I I

0 0

4 4

5 5

L L

6 6

7 7

~ ~

FRAME FRAME II II

!:II !:II

II II

I I

Link Link

2 2 2

3 3

-_5·-..-.._8~=·-· -_5·-..-.._8~=·-·

5 5

6 6

I I

R R

9 9 9

4 4

7 7

8 8 8

LINK LINK

9_1\ 9_1\

1~ 1~

9 9

~~ ~~

~ ~

l l

5 5

CROSSBAR CROSSBAR

TRUNK TRUNK

MCA MCA

MCB MCB

BAY BAY

Trunk Trunk

I I

0 0

lr lr

9 9

I I

I[~ I[~

AND AND

7.31 7.31

I[ I[

[ [

and and

5 5

PRIMARY PRIMARY

5 5

-'1' -'1'

]~ ]~

0 0

I~ I~

0 0

=~~-3·-:~·-·.-·~-~~=~-

~ ~

0_~[ 0_~[

_c::::=::::jJ_=== _c::::=::::jJ_===

I I

3 3

2 2

4 4

Link Link

8 8

6 6

'-----

- II II

u u

lltl lltl

I I

3 3

2 2

4 4

5 5 5

R R L

7 7 7

9 9 9

6 6

8 8

r:i:: r:i::

CROSSBAR CROSSBAR

..1 ..1

9 9

l~ l~

01 01

1~ 1~

1 1

5 5

___/ ___/

5 5

Trunk Trunk

"----L "----L

[ [

FRAME FRAME

LINK LINK

I I

0 0

NO. NO.

t t

=_1 =_1

0 0

··~of ··~of

9 9

I I

9 9

ll ll

5 5

TRUNK TRUNK

LC LC

5 5

= =

7 7 -

7-14 7-14

1~ 1~

t t

0 0

l~ l~

0 0

c=:::::l:l c=:::::l:l

I I

3 3

CH. CH.

2 2

0 0

4 4

5 5

L L

6 6

7 7

8 8

'----:E=:-X,TENSION '----:E=:-X,TENSION

9 9

I,__=--

I I

L L

Figure Figure

:--

s-r-

s s

HES HES

---4_ ---4_

T T

POIN POIN

TS TS PLT PLT

TS TS

SWITC SWITC

RELAY RELAY

6W 6W

200 200

AND AND

MC MC

AND AND

MTG MTG EQPT EQPT CH. 7 - NO. 1 CROSSBARAND CROSSBARTANDEM SYSTEMS

frame) or 320 trunks (with trunk link extension frame). The secondary ends of the links serve 200 office junctors. The trunk link frame is arranged to operate with a maximum of eight markers and 20 office link frames and will serve any combination of AMAand non-AMA trunks, limited only by the decade requirements and cabling considerations. The trunk link extension frame provides for a maximum of 160 trunks to which the trunk links are given access by a multiple between the primary and primary extension switches. The trunk link arrangement is symbolically represented in Figure 7-15. 3. Office Link This 2-bay frame and one-bay office extension frame are the same as the corresponding frames used in No. 1 local crossbar offices. A second extension frame may also be furnished in tandem offices to provide increased trunk capacity. The office link frame has a capacity of 200 links, the primary switches of which serve 200 office junctors. The secondary switches provide for 100 outgoing trunks if the switches are not split and a maximum of 200 or 300 outgoing trunks if the horizontal multiples of all switches are split. The extension frame has a capacity of 100 outgoing trunks. On the basis of 200 or 300 trunks per frame and a maximum of 20 office link frames (as limited by the marker), the physical maximum number of out going trunks per marker group is 4000 with one extension frame and 6000 with two extension frames. To insure uninterrupted service, a test group of trunks is divided between two office link or extension frames, and the frames are furnished and operated in pairs. The office link arrangement is symbolically represented in Figure 7-16.

7.32

by by

TRK TRK

OUT. OUT.

Secondary Secondary

Frame Frame

and and

Links Links

Link Link

BAY BAY

Connected Connected

I I

l l

BAY BAY

SECONDARY SECONDARY

FRAME FRAME

Office Office

Primar; Primar;

Office Office

Bays Bays

SYSTEMS SYSTEMS

LINK LINK

LINKS LINKS

OFFICE OFFICE

7-16 7-16

OFFICE OFFICE

TANDEM TANDEM

Channel Channel

BAY BAY

I I

1 1

PRIMARY PRIMARY

BAY BAY

Fi~ure Fi~ure

PRIMARY PRIMARY

TJO TJO

CROSSBAR CROSSBAR

FRAME FRAME

7.33 7.33

AND AND

JUNCTOR JUNCTOR

Complete Complete

GROUPING GROUPING

A A

by by

7-17 7-17

BAY BAY

Secondary Secondary

I I

r r

Frame Frame

CROSSBAR CROSSBAR

SECONDARY SECONDARY

BAY BAY

1 1

and and

SECONDARY SECONDARY

FRAME FRAME

•. •.

I.inks I.inks

Link Link

Connected Connected

Figure Figure

NO NO

LINK LINK

LINKS LINKS

TRUNK TRUNK

LINK LINK

TRUNK TRUNK

~ ~

Trunk Trunk

Prinary Prinary

T~unl~ T~unl~

llays llays

7 7

l l

TRUNK TRUNK

BAY BAY

PRIMARY PRIMARY

7-15 7-15

CH. CH.

PRIMARY PRIMARY

INC INC

TRK TRK "Figure "Figure

and and

ten ten

The The

the the

switch switch

to to

a a

an an

B, B,

link link

rear rear

The The

trunk trunk

to to

has has

the the

to to

an an

the the

each each

a a

7-17. 7-17.

is is

rings rings

and and

ten ten

controller controller relays relays

group group

200-point, 200-point,

link link

initial initial

the the trunks. trunks.

links. links.

serving serving

and and

kinds. kinds.

A A

and and

SYSTEMS SYSTEMS

and and

bay. bay.

with with

office office

B B

switches switches

two two

trunk trunk

an an

of of

mounted mounted

secondary secondary

with with

Four Four

is is

frame frame

change change

minimu~. minimu~.

compl.ete compl.ete

two two

links, links,

trunk trunk

200-point, 200-point,

Figure Figure

channel channel

switches switches

one one

a a

trunk trunk

the the

two two

links links

and and

A A

to to

ate ate

the the

trunks trunks

of of

in in

TANDEM TANDEM

casing casing

in in

to to

of of

outgoing outgoing

of of

interconnecting interconnecting

four four

junctor; junctor;

the the

and and

circuits, circuits,

primary primary

together together

frames frames

obtain obtain

four four

senders. senders.

panel, panel,

multicontact multicontact

incoming incoming

a a

arrangement. arrangement.

to to

A A

with with

provided provided

grouping grouping

secondary secondary

which which

and and

illustrate illustrate

kept kept

to to size size

Frame Frame

of of

80 80

the the

either either o£.100 o£.100

front front

relays, relays,

an an

links links

is is

secondary secondary

structure. structure.

link link

required required

on on

two two

a a

fuse fuse

mounted mounted

channel. channel.

is is

the the

as as

primary primary

CROSSBAR CROSSBAR

of of

on on

link, link,

the the between between

jumper.distributing jumper.distributing

40 40

a a

trunks trunks

of of

the the

in in

represented represented

7-18b 7-18b

7.34 7.34

group group

are are

switches, switches,

TJO TJO

as as

the the

way way

AND AND

controller controller

frame frame

connector connector

2-bay 2-bay

frame frame

and and

the the

up up

verticals verticals

maximum maximum

on on

primary-secondary primary-secondary

switches switches

as as

a a

office office

this, this,

effort effort

a a

Grouping Grouping

a a

trunk trunk

and and

a a

access access

distribution distribution

Each Each

two two

of of

senders senders

maximum maximum

connecting connecting

as as

a a

channel channel that that

to to

with with

and and

link link

is is

the the

made made

a a

four four

contains contains

multicontact multicontact

incoming incoming

2-bay 2-bay

such such

40 40

enclosed enclosed

strips, strips,

trunk trunk

to to

of of

so so

strips strips

switch switch

the the

7-18a 7-18a

inter.connect inter.connect distribution distribution

a a

is is

CROSSBAR CROSSBAR

to to

half half

of of

subgroup subgroup

secondary secondary

Link Link link link

and and primary primary

in in

of of

Junctor Junctor

serves serves

of of

having having

bay bay

growth growth

1 1

of of

frame frame

to to ~rames ~rames

is is

trunks trunks

sender sender

junctor junctor

a a

addition addition

NO. NO.

trunks trunks

serves serves

total total

Each Each frame frame verticals. verticals.

primary primary

ten ten

access access group group

groups groups

circuits circuits

enclosure. enclosure.

The The terminal terminal

connector connector

S-wire S-wire

other other

S-wire S-wire

sender sender

This This office office

outgoing outgoing

consists consists Sender Sender

referred referred frames frames

junctor junctor

In In

Figures Figures

increases, increases, The The

and and

arranged arranged

link link

frames frames

terminal terminal access access

used used

This This

Office Office

7 7 -

S. S.

4. 4. CH. CH. CH. 7 - NO. 1 CROSSBARAND CROSSBAR TANDEM SYSTEMS

JUNCTOR GROUPING FRAME

Figure 7-18a Junctor Groups - 4-4 Size Office

TRUNK OFFICE UNK JUNCTOR GROUPING FRAME LINK FRAMES FRAMES 200

200

Figure 7-18b Junctor Groups - 6-6 Size Office (Initially 4-4 Size)

7.35

and and

the the

four four

of of

so so

are are

other other

informa

call. call.

one. one.

sub

of of

(when (when

area area

office office

by by

other other

division division

kinds kinds

and and

any, any,

mark, mark,

number number

frames. frames.

ten ten

only. only.

and and

information information

the the

sender sender

treated treated

call. call.

or or

the the

of of

switch switch

if if

of of

the the to to

two two

SYSTEMS SYSTEMS

pulse, pulse,

marker marker

in in

arranged arranged

group group

each each

strapping strapping

AMA AMA

to to

The The

are are

kind kind

extended extended

switch switch

pulse pulse

the the

a a

frame frame

from from

class class

automatic automatic

completion completion

number number

sender sender

to to

trunks trunks

or or

is is

requiring requiring

of of

are are

the the

desired desired required required

kinds kinds

for for

dial dial

office office

are are

approximately approximately

one one

Each Each

These These

complete complete

for for

class, class,

the the

The The

Each Each

number number

dial dial

TANDEM TANDEM

transmits transmits

link link

originating originating

kind kind

trunk trunk

the the

operation). operation).

frames frames

secondary secondary

of of

and and

secondary secondary

from from

to to

the the

in in

and and

9. 9.

there there

Senders Senders

multiple multiple

It It

through through

calling calling

office. office.

selection selection

serving serving sender sender

trunks trunks

have have

complete complete

rate rate

to to

the the

at at

one one

the the

registers registers

to to

trunk trunk

kind. kind.

five. five.

of of

some some kinds. kinds.

arranged arranged

each each

(ANI) (ANI)

to to

the the

S S

different different

of of

When When

arranged arranged

independent independent

possible possible

CROSSBAR CROSSBAR

from from

and and

information information

assist assist

those those

kind. kind.

of of

corresponding corresponding on on

senders senders

of of

the the

tandem tandem

trunk trunk

two two

or or

PCI PCI

receives receives

required required

is is

and and

the the

revertive revertive kind kind serving serving

7.36 7.36

trunk, trunk,

registers registers

connects connects

marker. marker.

number, number,

a a

to to

other other 4 4

appears appears

AND AND

and and subgroups subgroups

or or

horizontal horizontal of of

etc. etc.

the the

appearances appearances

be be

it it

and and

of of

for for

to to

other other

point point senders senders

multifrequency, multifrequency,

required required

the the

controls controls

stores stores

appear appear

each each

frame, frame,

office. office.

links links

used used

greatest greatest

the the of of

0 0

entirely entirely

receives receives

receives receives group group

number number

office office

each each

may may

is is

to to

sender sender

the the

of of

access access

ten ten the the

subgroups subgroups

and and

is is

and and

for for

sender sender

may may

senders senders

the the

are are

senders senders

of of

horizontals horizontals

CROSSBAR CROSSBAR

codes, codes,

link link

identification identification

marker marker

through through

office office

at at

to to

information information the the

data data

serves serves

of of

has has

1 1

that that

all all

of of

number number

tandem tandem

called called sender sender

sender sender

ten ten

each each

multiples multiples

the the

cut cut switch switch

senders, senders,

senders senders

call call

sender sender

NO. NO.

tion tion

to to

the the

connector connector trunk trunk

office office

the the

other other

receives receives

terminating terminating

The The tandem tandem

sender sender

After After

a a through through

circuits circuits

that that

in in

links links number number is is

The The

requiring requiring

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and and

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exclusion exclusion

kind kind

senders senders same same cabled cabled

group group

horizontals horizontals

A A multiple multiple between between

of of

multifrequency, multifrequency, of of

The The

multifrequency, multifrequency,

7 7 -

6. 6. CH. CH. CH. 7 - NO. 1 CROSSBAR AND CROSSBAR TANDEM SYSTEMS

There are four types of senders and sender frames available, namely: revertive, PCI, dial, and multifrequency pulse. The pulsing used in transmitting the called number from the originating office to the tandem sender indicates the type of sender. The revertive pulse sender frame has a capacity of five revertive senders. This sender functions with trunks incoming from panel or crossbar offices that control the routing of the call partly or wholly on a revertive pulsing basis. It is used to complete calls to panel, crossbar, step-by-step, and manual offices. The revertive sender is arranged to register seven digits and to complete calls by revertive pulsing·, dial pulsing (4, 5 or 6 digits), and on a straightforward basis. PCI calls are completed by closing a circuit for the direct transmission of PCI pulses from the originating office over the tandem completing trunk. The PCI, dial, and multifrequency pulse senders are arranged for AMA, but will also handle non AMA calJs. They are able to register and out pulse a greater number of digits than the revertive sender and to complete calls by revertive, PCI, dial, and multifrequency pulsing and on a straightforward basis. The PCI sender frame has a capacity of three PCI senders. This sender is used in the completion through tandem of calls dialed by subscribers in panel and crossbar offices. PCI pulsing into the tandem office is used to obtain greater code capacity (640 as compared to 300 for revertive) and to permit outpulsing of party letters from the local office. It is arranged to register eight digits and to outpulse four to eight digits on a dial or multifrequency basis. The digits may be four or five numerals or four numerals and a party letter preceded, if desired, by 1-, 2~,or 3-code digits. The code digits may be transm~tted as registered or converted to any other values by translation from the marker.

7.37 CH. 7 ~ NO. 1 CROSSBARAND CROSSBARTANDEM SYSTEMS

The dial pulse sender frame and the multi frequency pulse sender frame have a capacity of four dial pulse senders and four multi frequency pulse senders respectively. The dial pulse sender is used in the completion through tandem of calls from step-by~stepsubscribers, from manual, DSA and toll switchboards equipped with dials, from other senders arranged for dial pulsing. The multifrequency pulse sender is used in the completion through tandem of calls from senders arranged to transmit multifrequency pulses and from manual, DSA, and toll switchboards equipped for multifrequency keypulsing. These senders will accept three to eleven digits and will outpulse one to eleven digits. The out pulsed digits may be as registered, 1, 2, or 3 digits prefixed to the registered digits to be outpulsed, the first three digits changed and on area calls, the first three registered digits may be deleted and the next three digits code converted. The dial pulse sender is arranged for bylink operation to avoid second dial tone to step-by step subscribers. With this feature, the first three digits following the directing code are registered in an incoming register which is connected to the tandem incoming trunk by the incoming register link •. Subsequent digits are dialed directly into the sender. The digits in the register are transferred to the sender through a sender register connector: The association of trunk, trunk link, and sender link frames is by direct cabling. The 160-trunk capacity of the basic trunk link frame is accommodated on ten primary switches. The added 160 trunk capacity of the trunk link extension frame is accommodated on ten primary switches. Bach switch accommodates 16 trunks in pairs on eight levels. The other two levels are used for discriminating purposes to serve the proper one of a pair of trunks involved in a given call. A group of ten trunks is considered to be of one type from the standpoint of sender requirements and code grouping as well as circuit features. It is cabled to appear as a primary switch group of ten trunks on the sender link frame. It is served, therefore, by that one type of sender to which

7.38

the the

in in

of of

a a

the the

and and

of of

at at

trans

trunks, trunks,

link link

and and

traffic traffic

level level

in in

the the

to to

two

on on

one one

the the

code code

panels, panels,

carry carry

use use

certain certain

a a

to to

trunks. trunks.

translation. translation.

example, example,

alarm alarm

further, further,

link link

the the

SYSTEMS SYSTEMS

between between

marker marker

trunk trunk

frame frame

levels levels

each each

To To

have have

translation, translation,

is is

on on

for for

on on

basis. basis.

destination destination

supply supply

consists consists and and

gives gives

leads leads

and and

completing completing

senders senders

to to

an an

ten ten

for for

on on

area area

two-out-of-five two-out-of-five

the the

may may

revertive revertive

trunk trunk

each each

associated associated

of of

still still

as as

a a

area area

for for

TANDEM TANDEM

multifrequency multifrequency

in in

leads leads

frame frame

terminated terminated

general general

frame frame

of of

switch switch

digits digits

resistance resistance

marker marker

regard. regard.

marker marker

proper proper

number number

on on

transmitting transmitting

the the

The The

the the

current current

units, units,

certain certain

that that

trunks trunks

for for

in in

connector connector

trunks trunks

characteristics characteristics

are are

foreigh foreigh

the the

senders, senders,

of of

the the

to to

This This

link link

of of

and and

on on

leads leads

idle idle

this this

Supply Supply

proportion. proportion.

maximum maximum

foreign foreign

designation designation

frame frame

to to

to to certain certain

CROSSBAR CROSSBAR

a a

both both

primary primary

for for

an an

in in

indication indication

necessary necessary

switches switches

in in

basis. basis.

this, this,

multifrequency multifrequency

group group

for for

on on

trunk trunk

equipment. equipment.

marker marker

distribution distribution

same same

of of

by by

7.39 7.39

these these

basis basis

to to

link link

arranged arranged

cabled cabled

varying varying

AND AND

systems systems

marker marker

that that

a a

differing differing

oscillator oscillator of of

one one

trunk trunk and and

type type

Current Current

distributing distributing

quantities quantities

in in

the the

of of

each each

are are

a a

are are

of of

required. required.

load load

the the

transmit transmit

digits digits

primary primary

but but

multifrequency multifrequency

arranged arranged

two-out-of-seven two-out-of-seven

trunk trunk

marker marker

groups groups

of of

is is

sender sender

same same such such

of of

to to

arranged arranged

a a

differing differing

Multifrequency Multifrequency

pulse pulse

unit, unit,

information information

a a

ten ten CROSSBAR CROSSBAR

characteristics characteristics

Because Because

or or

Since Since

the the

result result

Connector Connector

trunks trunks

in in

indication indication

give give

when when

on on different different

the the

groups groups

1 1

necessary necessary

not not

senders senders

of of

plan plan

to to

for for

function function

senders senders trunks trunks

dial dial

6-frequency 6-frequency

miscellaneous miscellaneous

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can can

of of

NO. NO.

transmit transmit

two-out-of-seven two-out-of-seven

basis basis

leads leads

transfer transfer

call. call.

These These

connect connect

marker. marker.

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this this

PCI PCI

when when

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selection selection

multiple multiple

frames frames marker marker The The

and and

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mit mit

The The

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serves serves

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equipment equipment

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approximately approximately

These These

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Marker Marker

Multifrequency Multifrequency

marker marker

· ·

7 7 -

8. 8.

7. 7. CH. CH.

or or

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to to

out

hold hold

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through through

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The The

indicator indicator

panel panel

panel, panel,

tandem tandem

office office

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Part Part

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SYSTEMS SYSTEMS

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point point

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TANDEM TANDEM

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connected connected

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CROSSBAR CROSSBAR

associated associated

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Operator Operator

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row, row,

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7.40 7.40

to to

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offices, offices,

AND AND

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through through

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call call

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the the

trunk trunk

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group group

circuit circuit

a a

Calls Calls

a a

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each each

translator translator

marker marker

operate operate

surge surge

information information

second second

horizontal horizontal

incoming incoming

private private

from from

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associated associated

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in in

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tandem tandem

straightforward straightforward

step-by-step, step-by-step,

to to

through through

the the

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to to

codes; codes;

trunk trunk

terminal. terminal.

voltage voltage

required, required,

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translator translator

crossbar, crossbar,

the the

on on

CROSSBAR CROSSBAR

of of

terminal terminal

routing routing

firing firing

connected connected

nine nine

equipment. equipment.

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exchanges, exchanges,

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and and

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which which a a

in in

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1 1

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wire wire

NO. NO.

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indicator indicator to to

PBX PBX

point point

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sender, sender,

official official office office

The The crossbar, crossbar,

connect connect

offices, offices,

going going

step, step,

switchboards. switchboards.

set set

branch branch

• • call, call,

outgoing outgoing

area area

magnets magnets office office

Marker Marker

7 7

9. 9. CH. CH. CH. 7 - NO. 1 CROSSBARAND CROSSBARTANDEM SYSTEMS

The translator frame, is a single-bay frame used in conjunction with th.e marker to provide for 6-digit translation for a maximum of five foreign areas with 60 routes for each area. Its use provides for selecting the best route to a particular office in a foreign area where there are several routes by which the tandem office can reach the foreign area. It is also used for selecting a particular PBX when several share a 3-digit code. 11. Trunks

The trunk frame~accommodate the numerous trunks used to provide incoming calls access to cross bar tandem switching equipment elements. The trunk frames are single-bay structures accou~odatingeither 23-inch mounting plate units or 30-1/2 inch mounting plate units. The frames have capacities of 10, 20, 30, 40 or 60 trunks depending on the apparatus involved. Trunks are grouped in decades of one to ten trunks numbered 00 to 09, 10 to 19, etc. or 50 to 59 on the trunk frames. The trunks in a decade have certain common requirements and are handled on a decade basis at the various trunk appearances. At the trunk link frame, each trunk decade (00 to 09, 10 to 19) is connected at the trunk link frame so as to contribute one trunk to each of the ten primary switches on the frame. Each primary switch accommodates a maximum of sixteen trunks, two on each level from 2 to 9. Trunks 00 to 09 will normally appear as the first of the trunks on a level and

7.41

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7.42 7.42

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- {S) {S) CH. 7 - NO. 1 CROSSBARAND CROSSBARTANDEM SYSTEMS

trunks 10 to 19 as the second. The trunk numbering consequently indicates by the units digit, 0 to 9, the trunk link primary switch on which it appears and by the tens digit, even or odd, the position on the level. Trunk frames fall into four general categories, Non-AMA, AMA, lOOB TSPS, and 2-way.

12. Non-A&~Trunks The non-AMA trunk frames are remote-control zone registration, through supervision, repeater supervision, simplex or composite supervision, PCI pulsing, MF pulsing, and Extended Area Service, Loop or E&M. Remote-control zone registration trunks are used for calls from panel offices arranged for remote-control zone registration. Charge pulses are sent to the originating office according to the rate cross connections in the trunk and the duration of the call. In the case of 2-rate trunks, the marker determines whether the lower or higher rate is effective. Reserve trunks are provided to handle calls for remote-control zone registration trunks which are under routine test. They are automatically substituted for any associated service trunk under test and are arranged to assume, automatically, the particular rate schedule of the trunk for which they may be substituted at the time. - - The through supervision trunks are used in completing calls from No. 1 Crossbar or panel offices. The repeated supervision trunks are used on calls involving revertive, dial or multifrequency pulsing from crossbar, panel, step-by-step, and No. 4 type offices, and from operators. The simplex or composite supervision trunks are used on dial pulsing or multifrequency pulsing calls from local or toll offices and may be arranged to rering forward with a simplex ringing signal.

7.43

5 5

the the

a a

is is

the the

tal tal

link link

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are are

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No. No.

be be

for for

are are it

the the

area area

office, office,

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in in

AMA AMA

PCI, PCI,

from from

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After After

with with

con

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trunks, trunks,

non-AMA non-AMA

PCI PCI

sender sender

trunk trunk

be be

trunks trunks

1, 1,

SYSTEMS SYSTEMS

and and

center center

through through

a a interrupter interrupter

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and and

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adjacent adjacent

No. No.

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on on

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supervision supervision

basis. basis.

directing directing

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associated associated

or or

TANDEM TANDEM

code code

step-by-step step-by-step

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In In

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(EAS) (EAS)

sender sender

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CROSSBAR CROSSBAR

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equipment. equipment.

multifrequency multifrequency

Service Service

interdigital interdigital

intended intended

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for for in in

or or on on

7.44 7.44

idle idle

the the

through through

the the

of of

trunks trunks

AND AND

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trunks trunks

pulsing. pulsing.

is is

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seized seized

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entry. entry.

originates originates

recorder recorder

perforate perforate

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offices offices

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together together

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purposes. purposes.

as as

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On On

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arranged arranged

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the the

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attached attached

CROSSBAR CROSSBAR

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1 1

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AMA AMA

Extended Extended

PCI PCI

Trunks Trunks

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office office

AMA AMA

completing completing

sender. sender.

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NO. NO.

connected connected

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time time

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answer answer

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When When

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number number trunks, trunks,

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accommodat1ng accommodat1ng

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dial dial Crossbar Crossbar

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building. building.

AMA AMA

7 7 -

13. 13. CH. CH. to

the

and

way

the

for

the

trunk

and

The

three

calls

the

by charge to

the

con

posi

the

link

the

The

code.

signals

the are of

the

seizure,

routed service and duration numbers

call

When

associated

for

these

it SYSTEMS

sender disconnects.

directs

then is

frame,

connection service

which

digits.

sender

for completing

circuit

the

controller

channel

closing

requests

followed

while

office

digits

called

the

and

trunks

charge.

link traffic signals

and

handling digit

and

operator's

circuit circuits assistance.

TANDEM

before

trunk

links

digits, recorded tandem

and

switchboard circuit

provide

digit

registers code

connection

through

the

over

card reverse-charge,

a lOOB

marker,

remaining

office

link

idle trunk

recording

position.

set

The

area

are to

position

operator

the

trunks.

sender

customer,

three

the the

this an

office

the

trunks

operator

the

in CROSSBAR

cover

called

calling

sender,

directing

The

maintaining

connected

sender

and

credit

transfer to

office to

and

data

7.45

sender

over

and operator

is area

digits other

transmission

directing

service trunk.

associated

with

AND

the

the The

for

the

calling an

marker

record

data

call

des1re

the

rec~rded trunks

for

the trunk

its

connected

tandem

itself trunk

recorded these

must

the

connect

office

setting

digits

is the marker

circuit.

After means

who

connector

has

traffic

the

dials

party, of

position.

dials

as toll

to the to

person-to-person, the

outgoing

CROSSBAR

are

number. associated

calls call.

associated crosspoints

the through

three

sender

trunk

tandem

received

soon

third

its

the

NO.

the

the digits transmitted The register

Subsequently

sender,

Special of processed called the tion

such customer transfers circuit. the call trunk talking connector identifying As services circuit connected through are customer

selected first sender desired supplying nects of Recording-completing with customers position.

assists

7 -

CH. CH. 1 - NO. 1 CROSSBARAND CROSSBARTANDEM SYSTEMS

When a customer dials the operator code, a recording completing trunk in the tandem office is seized which causes a tandem sender to be connected. After ANI (Automatic Number Identification) information is recorded, the sender passes a position request signal to the trunk. After receiving the call details, the position enables conversation to take place between the calling customer and the operator. The customer informs the operator of the called number and whether the call is person to person, station to station, station paid, collect, or special, and she then keys this information into her position register. ~when the position is reattached, the position calls in the data transfer circuit and the called number is passed from the position register through the data transfer circuit. There are a few types of calls which the traffic service position operator will not complete. They are: overseas calls, mar1ne operator calls, conference calls, mobile telephone calls, and sequence calls. In these cases, the operator initiates a transfer of the call. The trunk starts a trunk finder which cuases a cord-type tollboard operator to take up the call. The lOOB TSPS operator will be bridged on the transfer connection and will pass the call details. After this she releases her position, leaving the transfer connection under joint control of the calling customer and the cord type toll switchboard operator. Centralized dial coin trunks are furnished in a tandem off1ce to perm1~-the handling of calls dialed by coin subscribers. When the incoming coin trunk is seized at the tandem office, it connects to a sender through the sender link frame. From the sender link, the sender receives information identifying the trunk class and its data group number. The sender receives and registers the called number followed by the station paid start pulse consisting of 1500 and 1700 cps. After this the sender requests ANI from the originating office. Following receipt of the ANI information, the sender signals the trunk to bid for a position which in turn bids

7.46

on on

of of

be be

the the

rater rater

a a

the the

which which

times times

are are

trunk trunk

call call

terms terms

to to

having having

the the

and and

the the

number number

traffic traffic

for for

given given

traffic traffic

on on

which which

charges charges

must must

also also

mark mark

rate rate

circuits circuits

obtain obtain

the the

to to

point point

transfer transfer

number number

switches switches

in in

the the

CODE CODE

from from

position. position.

also also

scanning scanning

it it

a a

date, date,

a a

to to

are are

the the

used used

recorder recorder

overtime overtime

to to

number number

SYSTEMS SYSTEMS

registers. registers.

lZOO lZOO

switch switch

(1+) (1+)

trunk trunk

number, number,

the the

3600 3600

by by

to to

holding holding

rater rater

set set

data data

the the

is is

switches switches

busies busies

determines determines

calling calling

between between

Circuits Circuits

of of

requests requests

and and

number number

less less

rate rate

provides provides

on on

of of

switches switches

to to

above above

be be

the the

Should Should

center center

VACANT VACANT

scanning scanning

scan scan

The The

and and

The The

photograph photograph

a a

through through

and and

paases paases

TANDEM TANDEM

or or

called called

traffic traffic

equipment equipment

frame frame

rater rater

having having

indicate indicate

the the

service, service,

station station

leads leads

to to

one one

to to

treatment treatment

from from

rate rate

call call

circuits circuits

measurements measurements

sender sender

(CCS). (CCS).

crossbar crossbar

maximum maximum

initial initial

to to

the the

of of

period period

recording recording

maximum maximum

the the

recorder recorder

mark. mark.

rater, rater,

a a

the the

operator. operator.

automatically, automatically,

From From

period. period.

called called sender sender

closes closes

equipment equipment

10-second 10-second

used used

a a

the the

call call

rate rate

of of

seconds seconds

given given

The The

index index

the the

as as

CROSSBAR CROSSBAR

circuit. circuit.

regular regular

to to

appearances appearances

100-second 100-second a a

and and

the the

recorder recorder

Circuits Circuits

hourly hourly

and and

recorder recorder

the the

class class

The The

10 10

the the

various various

the the

of of

receiving receiving

7.47 7.47

or or

at at

seconds seconds

initial initial

are are

rated rated

AND AND

the the

by by

code, code,

Should Should

computer computer

came. came.

station station

well well

of of

initial initial

Recorder Recorder

up up

originating originating

digits digits

with with

sei1red, sei1red,

cameras cameras

cycle cycle

scan scan

be be

addition, addition,

office office

and and

usage usage

access access

accuracy. accuracy.

spaced spaced

scanning scanning

usage usage

the the

trunk, trunk,

as as

mark, mark,

call call

and and

the the

trans.fer trans.fer

passes passes

the the

In In

the the

set set

call call

six six

the the

rated rated

accurate accurate

the the

of of

this this

when when

times times

scanned scanned

for for

registers. registers.

seconds seconds

into into

Usage Usage

usage usage

duration duration

by by

the the

vacant vacant

to to

and and

CROSSBAR CROSSBAR

position. position.

registers registers

registers. registers.

the the for for

cannot cannot

a a

determines determines

data data

10 10

1 1

traffic traffic

desired desired

are are

traffic traffic

equally equally

provide provide the the

first first

sender sender

a a

hundred hundred

to to

the the

used used

10-digit 10-digit

100-second 100-second

NO. NO.

the the

controls controls ten ten

and and

usage usage

a a

The The

appearance appearance

The The

traffic traffic

and and

of of

holding holding

usage usage

over over

divided divided

provides provides

measure measure timer timer

provide provide

The The rater rater

duration duration

Traffic Traffic

is is for for

announcement. announcement.

be be

receives receives

the the

to to

manually manually

or or

information information

determine determine

combines combines

number number

periods. periods.

for for

which which

transmitting transmitting

marker marker

sender, sender, circuit, circuit,

which which

The The

7 7 -

14. 14. CH. CH. CH. 7 - NO. 1 CROSSBARAND CROSSBARTANDEM SYSTEMS

obtaining traffic data, such as overflow, group busy, peg count, load and usage. A single sided distributing frame is furnished adjacent to the traffic registers for terminating the many leads from the connecting circuits and for flexibility of cross connections between the traffic registers and the connecting circuits. 15. Service Observing Multiline service observing equipment for incoming trunks provide for service observing at a No. 12 service observing desk in the same or another building. This equipment consists of small surface-wired units and patching facilities mounted in relay rack bays. Each multiline service observing circuit has a maximum of 50 loop connectors arranged for patching to the relay-rack appearance of the trunks to be observed. 16. Floor Alarms The floor alarm unit accommodates the alarm relay equ1pment for a variable number of frames and aisles of equipment distributed over a maximum of two floors. It provides audible and visual signals under trouble conditions and supplements the alarms appearing on the individual frames. The audible signals by means of distinctive tones indicate the type of alarm. The visual signals in the form of floor and aisle pilots using differently colored lamps indicate the general nature and location of the trouble. The alarms may be transmitted to an alarm receiving center by means of alarm sending and transfer equipment when unattended operation of the tandem office is required. 17. Power The power requirements for crossbar tandem offices are similar to local No. 1 Crossbar offices and the same power plants may be used if available. For a new office a 302A plant for 24 and 48 volts is used. For zone resigtration trunk timers or master timers, a source of 22 volts ac is required. This is supplied from a relay rack mounted 506A power plant unit. A

7.48

in in

of of

is is

for for

frame, frame,

for for

the the

basic· basic·

bay bay

equip

Plants," Plants,"

at at

dial dial

PCI, PCI,

for for

system. system.

with with

office office

during during

a a

to to

and and

trunks trunks

test test

cabinet cabinet

other other

plants plants

supplied supplied

and and

the the

test test

action action

through through

has has

Power Power

battery battery

SYSTEMS SYSTEMS

and and

automatically automatically

single single

local local

is is

tone tone

tapped tapped

equipped equipped

positions, positions,

arranged arranged

supplementary supplementary

of of

and and

of of

115-volt, 115-volt,

testing testing

the the

transmission transmission

connector connector

trunk trunk

a a

circuits circuits

battery battery

provided provided

A A

power power

voltage voltage

pulse pulse

be be

Low Low

of of

incoming incoming

is is

frame frame

associated associated

registration registration

for for

and and

tests tests

be be

part part

TANDEM TANDEM

talking talking

the the

low low

obtained obtained

perforator perforator

may may is is

supply, supply,

voltage voltage

the the

One One

Corrective Corrective

existing existing

office office variety variety

furnish furnish

operator operator

its its

zone zone

"Telephone "Telephone

is is

at at

or or

Various Various

registers, registers,

incoming incoming

also also

It It

a a

the the

frame, frame,

but but

an an to to

frame, frame,

associated associated

records records

to to

the the

This This

plants. plants.

switchboards switchboards

provide provide

required. required.

personnel. personnel.

to to

malfunctions malfunctions

For For

CAMA CAMA

the the

may may

look look

48-volt 48-volt

CROSSBAR CROSSBAR

makes makes

7.49 7.49

if if

testing testing

test test

trunks trunks

from from

170-volt 170-volt

DSA DSA

test test

system. system.

from from

and and

failure failure

multifrequency multifrequency

trunks trunks

desired. desired.

systems systems

refer refer

The The

a a power power

AND AND

incoming incoming

frame, frame,

and and

office. office.

indispensable indispensable

or or

local local

frame, frame,

frame frame

for for

Test Test

required. required.

required required

volts. volts.

4000 4000

the the

printing printing

as as

some some

through through

trunk trunk

localize localize

taken taken

motors. motors.

4000 4000

and and

410B 410B is is

is is

plant plant

power power

test test

in in

above above

130 130

toll toll

pulse, pulse,

frame frame

used used

maintenance maintenance

for for

pulses pulses

current current

of of

and and

Trunk Trunk

18. 18.

are are

or or

plant. plant.

reel reel

CROSSBAR CROSSBAR

to to

Test Test

comprehensive comprehensive

switching switching

senders, senders,

trunks trunks

the the

power power

plant plant

1 1

operation, operation,

connector connector

a a

volts, volts,

sender sender

supplementary supplementary

terminating terminating

incoming incoming

405A 405A

additional additional

repeatedly repeatedly

integral integral

by by

all all

detect detect

NO. NO.

ringing ringing

Chapter Chapter

135 135 506A 506A

504B 504B required required

ringing ringing

60-cycle 60-cycle

require+ require+

charging charging

For For

output output filters. filters.

commercial commercial

by by

mentioned mentioned

trunks trunks

test test

CAMA CAMA

the the

revertive revertive

pulse pulse

tests. tests.

these these teletypewriter teletypewriter

The The

automatically automatically

Incoming Incoming

Sender Sender the the

capacity capacity

or or

an an

connector connector

equipment equipment

The The

in in

an an

MAINTENANCE MAINTENANCE

deficiencies deficiencies

7 7 -

2. 2.

1. 1.

As As

frames frames

applied applied form form

CH. CH.

SYSTEM SYSTEM

then then

circuit circuit

C. C.

ment ment Test Test

. .

a a

A A

the the

well well

be be

at at

posi

of of o-f o-f

frame frame

which which

relay relay

to to

by by

trace trace

The The

a a

service. service. as as

during during

The The

feature feature

delayed delayed

become become

stuck stuck

can can

is is

sender sender

make-busy make-busy

done done

to to

and and

in in

lamps lamps

group group

card card

calls. calls.

used used

tracing tracing

.,_ .,_

affording affording

from from

when when

is is

make-busy make-busy

positions positions

pulsing pulsing

.SYSTEMS .SYSTEMS

requiring requiring

the the

a a

DtP.TValS DtP.TValS

card card

.ss .ss

1n 1n

; ;

per per

frame. frame.

are are

indicate indicate

priming priming

of of

test test

single-bay single-bay in in

identify identify

keys keys

recorded recorded

associated associated

call call

ng ng

subgroup subgroup

subgroups subgroups

desired desired

are are

a a

frame. frame.

Frames Frames

man. man.

a1d a1d

to to

sender sender

remote remote

encountered encountered

TANDEM TANDEM

lamp lamp

CALLS CALLS

involved involved to to

CP CP

m; m;

test test

and and

Fig~re.7-20. Fig~re.7-20.

operates operates

is is

registers, registers,

is is

record record

the the

--···-·· --···-··

to to

't; 't;

to to

frame, frame,

holes holes

positions positions

test test

as as

any any

in in

jacks jacks

it it

and and

light light

sender sender

function function

this this

The The

......

t-he t-he

automatic automatic

which which

MB MB

provide provide

multifrequency multifrequency

telephone telephone

of of

troubles troubles

senders senders these these

frame, frame,

field, field,

frame, frame,

Connector Connector

service service

well well

CROSSBAR CROSSBAR by by

are are

r"' r"'

......

information information

trunk trunk

trunks trunks

when when

7.50 7.50

the the

to to

TELEPHONE TELEPHONE

calls calls

maintenance maintenance

numbered numbered

~~ ~~

of of

as as

which which of of

punching punching

removing removing

connector connector

and and

a a

AND AND

alarm alarm

these these

is is

,.,.,1 jack jack

the the

primary primary

load load

PCl PCl

stuck stuck

by by

Remote Remote

are are

in in

number number

There There

tested tested

a a

by by

......

illustrated illustrated

an an

+o +o

a a

sender sender

ordinary ordinary

lamps lamps

of of

The The

recorder recorder

that that

outgoing outgoing

perforator. perforator. with with

outgoing outgoing

make-busy make-busy

'" '"

is is

frame frame

use use

made made

not not

and and

SWITCHING SWITCHING

indicate indicate

an an

canceling canceling

SC SC

a a

aCkS aCkS

recorder recorder

of of

operation operation Recorder Recorder so so

CROSSBAR CROSSBAR

.; .;

is is

stuck stuck

automatically automatically

Make-busy Make-busy

of of

identify identify

to to

of of

for for

of of

are are

1 1

' ' J

directly directly

trouble. trouble.

senders, senders,

the the trouble trouble

establishment establishment

sender sender

manual manual

to to

any any

connections connections

TANDEM TANDEM

~0. ~0.

ackS ackS

path path

. .

the the

J jacks jacks

testing testing

senders, senders,

trouble trouble

of of light light

tions tions

the the

busy. busy.

the the

assignments assignments

as as

senders; senders;

predetermined predetermined

means means

accommodating accommodating

The The record record

The The

and and

record record read read transverters. transverters.

Trouble Trouble

equipment. equipment.

Sender Sender

printed printed

Associated Associated

means means

make-busy make-busy

of of

7 7 -

The The

3. 3.

4. 4.

CH. CH.

CROSSBAR CROSSBAR

3-digit·translation 3-digit·translation

path. path.

sequence sequence D. D. CH. 7 - NO. 1 CROSSBARAND CROSSBARTANDEM SYSTEMS

The call arrives in the tandem office over an incom ing trunk and leaves over an outgoing trunk. The incoming trunk may be selected by an operator, a local office, a tandem office, or a dial toll office. The procedure in the tandem office is the same in any case. As shown in Figure 7-20, each incoming trunk has two major appearances in a crossbar tandem office; one on the trunk link frame (used for the talking connection) and one on the sender link frame (used for passing information to the common control equipment). The trunks are arranged in decades on the sender link frame to permit the sender link to provide to the sender information which is common to ten trunks. The sender link frame is the first of the trunk appearances to be used. It consists of two sets of cross bar switches, primary and secondary. The incoming trunks appear on the primary switches and the senders on the secondary.

TRUNK LINK OFFICE LINK FRAME FRAME

TRANSMISSION PATH OUTGOING INCOMING {9) TRUNK - TRUNK r r 1 - ,__ {9} (9) CONNECTOR CONNECTOR

{7) (6) {l)

SENDER LINK FRAME

• (5A) FOREIGN {4) (5) ... SENDER MARKER ,, AREA (3) (2) TRANSLATOR MARKER '--- CONTROLLER ~ CONNECTOR u- ..

Figure 7-20 Path of a Call Through a Crossbar Tandem Office

7.51

a a

as as

that that

the the

soon soon

is is

trunk trunk

the the

on on

and and

the the

code) code)

an an

the the

free free

the the

serve serve

from from

As As

link link

idle idle sender sender

(The (The

7) 7)

derives derives

begin begin

decoding decoding

decade decade

marker marker

is is

marker marker

signals signals

trunk, trunk,

• •

(connec

from from

an an sender sender

connection connection

turn turn

connector connector

from from

frame frame

(the (the

it it to to

the the

which which

or or

also also

seized, seized,

that that

6) 6)

and and

it it

seize seize

SYSTEMS SYSTEMS

the the

. .

frames, frames,

connector connector

seizes seizes

sender. sender.

sender, sender,

The The

and and

sender sender

in in

incoming incoming

link link

on on

the the

signals signals sender sender

The The

signals signals

to to

link link

connection connection

may may

link link

to to

was was

trunk. trunk. link link

it it

obtained obtained

terminated. terminated.

fr~~e fr~~e

the the

it it

which which

up up

first first

links links

the the

link link

call, call,

digits digits

4) 4)

the the

sender sender

derived derived

idle idle

connect connect

outgoing outgoing

TANDEM TANDEM

which which is is

(1) (1)

(connection (connection

was was

to to

seized, seized,

sender sender

frames frames

frame. frame.

received, received,

to to

an an

of of

the the

trunk trunk

marker marker

link link

trunk trunk

the the

from from

sender sender

sets sets

marker marker

marker marker frames frames

is is

pulses. pulses.

idle idle

trunk trunk

through through

(connection (connection

three three

connection connection 1) 1)

the the

outgoing outgoing

office office

the the

trunk trunk

the the

link link

which which

the the

been been

The The

an an

then then

attached, attached,

link link

the the

trunk trunk

instructs instructs

of of

the the

CROSSBAR CROSSBAR

to to

cuts cuts

the the

relays relays

trunk trunk of of

selects selects

7.52 7.52

connector connector

idle idle

(connection (connection

with with

information information

routing routing

first first

is is

function function

for for

terminated terminated

received received

have have

completes completes

the the

~ncoming ~ncoming

AND AND

then then

point, point,

with with

sender sender

serves serves

an an

instructions instructions

office office

pair pair

sender sender

from from

and and

turn turn

is is

the the

the the for for

the the

calls. calls.

incoming incoming

office office

of of

terminated terminated

5). 5).

route route

preceding preceding

simultaneously; simultaneously;

of of

(connection (connection

seizes seizes

the the

This This

marker marker

the the

in in

connect connect

for for

the the

for for sender sender

this this

of of

that that

is is

digits digits

or or

incoming incoming controller controller

switches switches

operation. operation.

the the

testing testing

its its

with with

to to

in in

trunk trunk

marker marker

on on

connector connector

the the

other other

At At

associated associated

then then

the the

pair pair

passes passes

an an

CROSSBAR CROSSBAR

nwuber nwuber

of of

releases releases

The The

pair pair

things things

which which

required required information information

tests tests

1 1

associated associated

The The

outpulsing outpulsing

three three

group group

calls. calls.

as as

completes completes

as as

testing testing

which which

the the

along along

marker marker

marker. marker.

the the

one one

serve serve

the the

started started

8), 8),

sender sender

two two

(connection (connection

stored stored

the the

2). 2).

crossbar crossbar

controller controller operator operator

marker marker

~0. ~0.

on on

to to

connector connector

the the

sender sender

registering registering

marker marker

which which

release release

above. above.

incoming incoming

soon soon

When When

soon soon

This This

the the

to to

the the

leads leads

trunk trunk

connected connected

other other

the the

7 7

to to

also also

When When

knows knows

starts starts

does does

link link

The The

for for

arrangement arrangement

The The

marker marker

As As As As

of of

link link

the the

is is

controller controller

3). 3).

marker marker

free free

test test

switch switch

it it

information information

access access

operates operates

decodes decodes

passes passes

CH. CH. -

it it

the the

serve serve

releases releases

(connection (connection

stage stage

now now

the the

sender sender the the

through through

(2) (2)

marker marker

(1) (1)

(3) (3)

mentioned mentioned

information information

(2) (2)

trunk trunk

the the

arrangement.) arrangement.)

(connection (connection cross-connections cross-connections

marker marker

as as link link

to to outgoing outgoing

through through has has

marker marker

to to

tion tion originating originating idle idle

which which decade decade

sender sender

s·ender s·ender

controller controller

signals signals pulsing. pulsing. CH. 7 - NO. 1 CROSSBAR AND CROSSBAR TANDEMSYSTEMS

another call but only up to the point where the outpulsing instructions are passed to the sender. For the ca.ll in progress, the marker maintains a path to the sender via the t~unklink connector, the incoming trunk, and the sender link (connections 7, 8 and 3). · When the outgoing trunk is seized and made busy, the trunk selection relay in the marker indicates whether the trunk is located on the even or odd office link frame. The marker then causes the trunk link frame to cut through the test leads associated with the junctors to that office link frame. The office link frame·cuts through to the marker the test leads associated with the office links serving the selected outgoing trunk. The marker now has access to the test leads for the trunk links, junctors, and office links, and it proceeds to set up the connection from the incoming trunk to the out going trunk. It makes the channel test by testing groups of three leads simultaneously, selects one group, and then closes the crosspoints to establish the selected channel {connection 9). The marker signals the sender that the path has been established and then releases from the trunk link and office link frames. The sender then sends a signal forward and upon receipt of a go signal it outpulses as it had been directed by the marker. After outpulsing is completed, the talking path is cut through. The sender and sender link then release and the call is under control of the incoming trunk. When the incoming trunk receives a release signal from the calling end, it releases the switches through the office. 1. Call Requiring 6-digit Translation A call requiring 6-digit translation follows the same method of operation as described above for a call requiring 3-digit translation up to the point of marker seizure. Since this sender is arranged for 6-digit translation and the first

7.53

the the

local local

two two

are are

them them

to to

a a

zone zone

and and

the the

All All

uses uses

of of

no no

relay. relay.

calls calls

or or

and and

the the

before before

separate separate

called called

which which

senders. senders.

tandem tandem

offices. offices.

sent sent

the the

at at

one one

Where Where

are are

where where

be be

zone zone

marker marker

marker marker route route

form form

SYSTEMS SYSTEMS

Operator Operator

initial initial

and and

control control

relay relay

are are

· ·

building. building.

numbers numbers

tandem. tandem.

to to

a· a·

digits digits

for for

rates, rates,

overtime overtime

involved involved

translates translates

the the

The The

the the

coin coin

.causes .causes

registration registration

calls calls

used. used.

crossbar crossbar

office office

above. above.

located located

six six

two two

and and

route route

than than

of of TANDEM TANDEM

Office Office

determines determines

trunks trunks

remote remote

have have

three three

be be

various various

originating originating

a a

which which

near-by near-by

zone zone

various various

the the

relay relay

form form

for for

rates, rates,

as as

crossbar crossbar

a a

are are

handle handle

and and

than than

arranged arranged

local local

handle handle

for for

the the

translator translator

Local Local

for for must must

sixth·digits sixth·digits

rather rather

first first

in in

two two

initial initial

be be

from from

the the

this this

area area

pulsing pulsing

the the

at at

described described

call call

operators operators waits waits

CROSSBAR CROSSBAR also also

code code

more more

known known

also also

Registration Registration

operate operate

9 9

or or

and and

control control

at at

indications. indications.

described described

and and

area area

the the

for for with with

the the

may may

at at

7.54 7.54

as as

is is

to to

this this

to to relay relay

take take

·translator ·translator

can can

AND AND

tandem tandem

options options

can can

this this

Zone Zone

far far

SA). SA).

0 0

2 2

applied. applied.

for for

signals signals

of of

sender sender

to to

called called

handled handled

route route

office office

of of

marker. marker.

trunk trunk

remote remote

This This

fifth, fifth,

area area

indicate indicate

be be

revertive revertive

have have

by by

foreign foreign

codes codes

decodes decodes a a

Dialing Dialing

A A

thus thus

60 60

from from

the the

assistance assistance tandem tandem

the the

intervals intervals arranged arranged

tandem tandem

functions functions

was was

an an

to to

To To

by by

registers registers

completed completed

, ,

in in

CROSSBAR CROSSBAR

Control Control

of of

is is

groups groups

using using

area area

digits digits

the the

Zone Zone

1 1

is is

information information

is is

trunks trunks

calls calls

foreign foreign

fourth, fourth,

operation operation

marker marker

(connection (connection

one one

number number

NO. NO.

originating originating Crossbar Crossbar

Coin Coin with with

rate rate

Ass1stance Ass1stance

trunk trunk

examines examines

rates. rates.

registrations registrations

The The

Calls Calls

overtime overtime periods. periods.

registration. registration.

handled handled

controlled controlled

equipment. equipment.

Crossbar Crossbar

charging charging

message message

charging charging

this this

Remote Remote

The The

to to

call call the the

in in

associated associated

The The

operates operates

The The

three three The The

calling calling

Where Where

NOX/NlX NOX/NlX

Any Any

7 7 -

3. 3.

2. 2.

= =

X X

N N

CH. CH.

NOX/NlX NOX/NlX 1 a

be non

four

has

As more of used ·

the

and

the

cross PBX's

to This reach

tandem

of it

by is first

compute,

offices

central

tandem within

arranged

in and

six-digit

are

different

SYSTEMS

called

and groups

exceed tandem is

operator.

extensions

purposes the one

and

deposit also

until

employ translation number.

on digits

traffic

shared in extension for

translation series

customer

maximum

series recognize

that number.

crossbar

the

shown PBX

PBX code

of digits

Crossbar

tandem is

when

TANDEM

charges.

which must

only sender calls is

digit

each

P.B.X. digit

for

will varies any

initial

crossbar from

codes number

code

accomplished can

number arrange

numbers

operator

and

No. The

office one codes six number

calls

with

six-digit

the

these

is used

possible seven

of extension

routed

crossbar

direct

and type

CROSSBAR

dialed

operator on overtime and

the

the marker

P.B.X.

limited

signal on

PBX

than

entire

of Exchange) office 55 the

outpulse

group,

code

This

AND

is The

dial 7.

The P.B.X.'s code

handled

tandem, the

that the of local

when

and

monitor

panel senders.

using

example, more nonshared not

ahead

standard

indialing,

call

office.

monitor is

overtime in trunk

Branch

PBX. a

for to

and

and go

central office that sixty reservation

For

7-21.

Dialing

code.

office

does basis

and

outpulsing

digits

CROSSBAR

the

period.

per Features

one

so efficiently.

local station

served.

association tandem

crossbar

P.B.X.

type

arrangement traffic

be trunks

the

request time

(Private

Inward delay

than

Figure the bar assigning central The translation

assigned three ten, where office many shared required For permits required most shared calls. assigned outpulsed office

coin

NO.

to This to a initial request, by charges

originating to can This

This PC! received

Centrex a.

·7

CH.

or or

to to

in in

and and

by by

exit exit

in in

area area

by by

as as

been been

tone tone

digits digits

to to

crossbar crossbar

the the

so so

during during that that

on on

an an

the the

be be

which which

and and

out

with with

already already

connec

P.B.X. P.B.X.

exten

calls calls

the the

numbers. numbers.

either either

affected: affected:

to to

in in

system. system.

have have

operation operation

attendent attendent

dial dial

extension extension

may may

to to

features features

code code

translation. translation.

dial dial

in in

three three

digits digits

the the

basic basic

the the

does does

SYSTEMS SYSTEMS

following, following,

generally generally

frame frame

office office

received received

connection connection

calls calls

dialing dialing

area area

Service Service

deleted deleted

the the

message message

equipment equipment

to to

second second

a a

required required

proceed proceed

10,000 10,000

each each

which which

is is

office office

and and

code code will will

the the which which

other other

the the

are are

be be

to to

by by

second second

these these

first first

calling calling

for for

link link

around" around"

office office

up up

s s

reach reach

of of

new new

the the

assistance assistance

are are

TANDEM TANDEM the the

is is

of of switching switching

to to

call. call.

the the

is is

then then

customer.on customer.on

additions additions

to to an an

six-digit six-digit

The The

Traffic Traffic

Tandem Tandem

or or

in in

of of

sets sets

group) group)

share share

office office

number number

means means

equipment equipment

or or

many many

adjuncts adjuncts

"loop "loop

and and

note note

completed completed

through through code code

office office

(access (access

P.B.X.

nonovertime nonovertime

receive receive

indialing indialing

without without

the the

during during

seizures seizures

plus plus

extension extension

tandem tandem

number number

toll toll

can can

the the

Of Of

type type

through through

be be

digits digits

seizures seizures

CROSSBAR CROSSBAR

block block

extensive extensive

a a

the the

7.56 7.56

This This

trunk trunk

Charging Charging

basis. basis.

For For

and and

major major

area area

marker marker

unit unit the the

a a

unused unused

Dialing Dialing

of of

the the

Crossbar Crossbar

code code

requiring requiring

tandem tandem

"9"), "9"),

7-digit 7-digit

authorized authorized

changes changes

can can

on on

AND AND

promotes promotes

are are

this this

marker marker

manner manner

several several

back back

others. others.

four four

an an PBX's PBX's

a a

to to

the the

of of

the the

local, local,

toll toll

Out Out

CAMA CAMA

home home

attendent attendent

marker marker

way. way.

each each

any any

connection connection

to to

by by

area area

of of

extensions extensions

involve involve

to to

trunk. trunk.

call call

for for

calls calls

all all

on on

or or

significance, significance,

separate separate

message message

by by

and and

rather rather

there there

mention mention

the the

Three Three usual usual

Two Two

equipment. equipment.

one one

on on

(usually (usually a a

crossbar crossbar

use use

feature feature

PBX PBX

toll, toll,

of of

not not

the the

home home

CROSSBAR CROSSBAR

usual usual

outdialing outdialing

several several

In In

attendant. attendant.

first first tandem, tandem,

one one

P.B.X. P.B.X.

assigned assigned

but but

recently recently

the the

Features Features

appearance appearance

connected connected

shared shared

a a

on on

1 1

local local

some some

do do

CAMA CAMA

on on

the the

dialing dialing

from from

code code

For For

assigning assigning

a a is is

and and

dialed dialed

from from

make make

PBX PBX

This This

PBX PBX

tion. tion.

addition addition

in in that that

required required

incoming incoming

the the the the causes causes

If If

an an

is is

the the indialed indialed

is is

sion. sion.

pulse pulse

NO. NO.

a. a.

existing existing changes changes

added added

such, such, In In tandem, tandem,

with with

Position, Position, Most Most

Other Other

7 7 -

5. 5. CH. CH.

Tandem Tandem Crossbar Crossbar Through Through Dialing Dialing Out- and and In- PBX PBX 7-21 7-21 Figure Figure

D-

MODIFIED MODIFIED CIRCUIT CIRCUIT EXISTING EXISTING

L--...J. L--...J.

li+J li+J

\ \

,, ,,

CIRCUIT CIRCUIT I I I- NEW NEW

,.....,-, ,.....,-,

DIALING DIALING

KEY: KEY:

OUT• OUT• TRANSLATOR TRANSLATOR

"''IIII "''IIII EQUIPMENT EQUIPMENT

t t

AMA AMA

TO TO

t t

-- ======-- = = - ..J ..J L--

======

CONNECTOR CONNECTOR

::: ::: BUSY BUSY

TRUNK TRUNK

1---

MARKER MARKER

SENDER SENDER

GROUP GROUP

- ..= ..= I I

rl rl EXTENSION EXTENSION

OUT-DIALING OUT-DIALING

MARKER MARKER

ffiJ ffiJ

fLEL. fLEL.

PBX PBX J J --- - - r E) E)

COMPLETION) COMPLETION) ""'IIII ""'IIII

~ ~

FORWARD FORWARD

I I

Ac~i~~~G~NT~s Ac~i~~~G~NT~s

-- _j _j II II

LINK LINK

LTRUNK LTRUNK

PBX PBX

TO TO I I

H H

SENDER SENDER NUMBER NUMBER ...., ....,

ON-OOAUNG ON-OOAUNG

n n .. .. l. l.

. .

l l II II

r--

...., ....,

1..-.- LISTEDl LISTEDl ......

ANT ANT

ATTEND• ATTEND•

~':.?:.J ~':.?:.J - L,....., L,....., .J .J

PBX PBX --

I I ATTENDANTS ATTENDANTS MES. MES. .----1 .----1

TRUNK TRUNK

r--, r--,

AND AND I I .I .I

I I INC. INC.

I I

~ EXTENSIONS

0 0 I I

lJ!t lJ!t DP

PBX PBX TO TO

r--, r--,

EXTENSION EXTENSION IN·DIALING IN·DIALING

PBX PBX '----...-

!:!ill !:!ill

I I

- - - L-

WORLO WORLO TO TO

r:.:A~I: r:.:A~I: . .

_r--"1 _r--"1 I I

TRUNK TRUNK

OUT·OIALONG OUT·OIALONG

TRUNK TRUNK

4 4 INC. INC. MF MF

PCI, PCI, DP, DP,

FRi,ME FRi,ME f':RAME f':RAME

LINK LINK

OFF'ICE OFF'ICE

_J _J _ _ TRUNK TRUNK L--

II II

. . TRUNK TRUNK I I 1 1

INC. INC.

II II

II II I I 1 1 SWBD.:--i) SWBD.:--i) TOLL TOLL

r----, r----,

OPERATOR OPERATOR OFFICE OFFICE

ZERO ZERO ORIG. ORIG. FROM FROM

with with

it it

AMA. AMA.

the the

frames frames

to to

same same

CAMA CAMA

version version

for for

number. number.

office. office.

of of

tandem tandem

the the

service service tandem tandem

and and

(CAMA) (CAMA)

tandem tandem

billing billing

perfora

SYSTEMS SYSTEMS

manner, manner,

on on

TRUNK TRUNK

OUTGOING OUTGOING

as as

first first

trunk trunk

for for

tandem tandem

disconnect, disconnect,

traffic traffic

arranged arranged

the the

centralized centralized

crossbar crossbar

the the

crossbar crossbar

subscriber subscriber

purposes purposes

TANDEM TANDEM

functions functions

a a

limited limited

the the crossbar crossbar

tapes. tapes.

of of

a a

centers centers

description description

of of

the the

a a

Accounting Accounting

recorded recorded

of of

and and

with with

recorded recorded

the the

in in

AMA AMA

CAMA CAMA

time time

is is

offices offices

using using

ACCOUNTING ACCOUNTING

when when

calling calling

aid aid

billing billing

CROSSBAR CROSSBAR

of of

into into

call call

diagram diagram

the the index, index,

tandem tandem

detailed detailed

Message Message

provide provide

local local

that that

the the

data data

and and

for for

additional additional

7.58 7.58

accounting accounting

local local

AND AND

to to

AMA AMA

offices offices

However, However,

MESSAGE MESSAGE

in in

add add

more more

· ·

block block

an an

are are

data data

AMA, AMA,

with with

NO. NO.

version version

CIRCUIT CIRCUIT

to to

answer, answer,

called called

billing billing

all all

PC! PC! of of

as as

crossbar crossbar

Billing Billing

and and

14. 14.

for for

introduced introduced

SENDER SENDER

Automatic Automatic

of of

to to

CALLING CALLING

CROSSBAR CROSSBAR

the the

calls calls

processing processing

possible possible

CONTROL CONTROL

first first

record record

1 1

tape tape

AUTOMATIC AUTOMATIC

in in

processed processed it it

AMA AMA

been been

time time

to to

message message

the the

Functional Functional

Chapter Chapter

broader broader depicts depicts

NO. NO.

elements elements

of of

OR OR

arranged arranged

are are

A A

the the

include include

in in

appropriate appropriate

operator. operator.

used used

special special

paper paper

have have

FROM FROM

7 7 -

OFI'ICE OFI'ICE

7-22 7-22

CENTRAL. CENTRAL.

7-22 7-22

area, area,

is is

The The

Centralized Centralized

PANEL. PANEL.

making making

CAOSS8AA CAOSS8AA --

be be

on on

tapes tapes

required required

CH. CH.

CENTRALIZED CENTRALIZED

given given

CAMA. CAMA.

Figure Figure

called called

tions tions

is is

features features

complete complete

facilities facilities are are

The The

numbers, numbers,

purposes purposes machines machines

Figure Figure

office office

position position

E. E.

of of system system would would CH. 7 - NO. 1 CROSSBARAND CROSSBARTANDEM SYSTEMS

On AMA calls, the calling number may be registered by an operator or by multifreqi.tency pulsing from an originating local office arranged for automatic number id~ntific~tion.For operator identified calls, the sender causes the position link to connect the subscriber to an operator at the CAMAswitchboard.

The AMA equipment consists primarily of a switch board, perforators, position links, transverters, master timer, transverter connector, billing indexer, recorder, call identity indexer, 3-digit incoming register and link, sender register connector, 10-digit incoming register and link, data transfer, rater, tim~rlink, and charge computer frames. The three digit incoming register and link (3-digit register) and its associated sender register connector are used in step-by-step areas to avoid second dial tone. The 10-digit incoming register and link equip ment is also used in step-by-step areas; however, all digits are registered in the register and upon completion of dialing, this information is transmitted to the MF sender by way of the data transfer circuit.

7.59