CHAPTER 7 NO. 1 CROSSBAR AND CROSSBAR ... - Jean GODI
marker. This permits any directory number (vertical side. LDF) to be assigned to any "line" circuit (Col. -Sw.-Vert. horizontal side LDF) as shown in Figure 7-2.
CHAPTER 7 NO. 1 CROSSBAR AND CROSSBAR TANDEM SYSTEMS 7.1 NO. 1 CROSSBAR SYSTEM
A. GENERAL The No. 1 Crossbar System was developed in the mid-1930's to overcome some of the disadvantage s of the Panel System. For instance, No. 1 Crossbar offered better transmission characterist ics by using precious metal contacts in talking path connections; gave one appearance to each s_ubscriber line on the frames for both originating and terminating traffic; and PBX hunting lines could be added without number changes. No. 1 Crossbar also made possible shorter call completing times and required less system maintenance. Since it was expected that this system would be used largely in panel areas, revertive pulsinfi was employed for both incoming and outgoing traff~c. The o. 1 Crossbar System is also a common control system; its originating and terminating equipment each has its own senders which function with the markers to complete subscribers • connections. A simplified view of the overall equipment arrangement is shown in Figure 7-1. I ,.--.._.;;;.._~~==---r-, ~_.~ I
ORIG. OFFICE
SUBS. SDR.
ORIG. MKR.
TERM.
SDR.
Figure 7-1 Simplified Block Diagram - No. 1 Crossbar System
7.1
CH. 7 - NO. 1 CROSSBAR AND CROSSBAR TANDEM SYSTEMS
From a traffic standp oint the major No. 1 Crossb ar dial system frames may be. divided into two genera l classe s: Termin ating Equipm ent Origin ating Equipm ent Incomin g Frame Group Incomin g Trunk Frame Incomin g Link Frame Incomin g Link Extens ion Frame Termin ating Sender link Frame Termin ating Sender Frame Termin ating Marker Connec tor Frame Termin ating Marker Frame Number Group Connec tor Frame Block Relay Frame Line Distrib uting Frame Line Choice Connec tor Frame Line Juncto r Connec tor Frame Line Link Frame
Line Link Frame Distri ct Frame Group Distri ct Juncto r Frame Distri ct Link Frame Subscr iber Sender Link Office Link Frame Office Extens ion Frame Subscr iber Sender Frame Origin ating Marker Connec tor Frame Origin ating Marker Frame
Two distrib uting frames are also provid ed. The Main Distrib uting Frame (MDF) is used for cross-c onnect ing the subscr iber and trunk cable pairs to the crossb ar frames . The Line Distrib uting Frame (LDF), provid es a means of cross-c onnect ing the line link frames to the termin ating marker . This permit s any directo ry number (vertic al side LDF) to be assigne d to any "line" circui t (Col. -Sw.-V ert. horizo ntal side LDF) as shown in Figure 7-2. LINE L/NI< PRIMARY SW. VERTICAL
L.D.F. T
R
.5
M·l M·2.
R·PTY CALL.•
v
H
Figure 7-2 Distrib uting Frame Connec tions for No. 1 Crossb ar Line Link Frames 7.2
· CH. 7 - MQ. 1 CllOSSBAl AID ClOSSIAI. TANDEM SYSTEJIS .
.
'
The equipeat re~;r.ed to 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. PRAMH EQUIPMEHT 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
CROSSBAR AND CROSSBAR TANDEM SYSTEMS
CH. 7 - NO. l
fo;r outprim ary switc hes; with dist rict.. junc torsincom . going calls ,and with line junc tors for line ing,. . calls . The assig nmen t of lines : to the of t junc tors for incom ing call s. The assig nmen load lines to the line link frame is gove rned byline char acte risti cs, calc ulate d by the CCS perevia tion for both in and out call s. CCS is an abbr ent of for "Hun dred Call- Seco nd Per Hour " meas urem line load 1nd1cat1.ng the sum of the leng th . of the time for each call on the line is one hour
and The cross bar custo mer' s line is assig ned to, ary has exclu sive use of a vert ical of a prim cros sbar switc h. The prim ary switc h has ten hori zont al path s with whic h this vert ical may fic, conn ect. The ten path s hand le all the traf a on s both outw ard and inwa rd for all the line firs t sing le switc h. The firs t vert ical on the is e fram ten prim ary switc hes on each line link test and used to obta in acce ss to busy lines for ary veri ficat ion purp oses . Thes e ten primhes are switc swit ches , plus the ten secon dary load fic traf the calle d the "bas ic unit ." Sinc e ten the load ally for nine teen lines does not norm ly, ient effic hori zont al path s, or line links addi tiona l switc hes for addi tiona l lines are adde d later ally to form what is known as a hori zont al group ·shown in Figu re 7-4.
a multipolar magnet, consisting of a central compound bar, around which are uniformly distributed a number of smaller bars, which are branches of the former ...
dulatory currents of electricity, whereby a number of telegraphic signals can be sent simultaneously over the same circuit, in either or in both directions, and a ...
bratory diaphragm to indenta traveling sheet of tin-foil or other .... face extend the side walls of box K, as shown. .... tails of construction of my apparatus and the.
vals with the sound vibrations produced in the atmosphere by the voice of the person. Speaking into the mouth-piece. The electro magnet in', being mounted ...
25 to a switching mechanism at the central sta tion, and from said mechanism leads normally to ground or return. Further, said mechan ism is so arranged that by ...
WITNESSES: S. foran Stavoren. INVENTORS, banllennoller. УгиллÑ. Ry Corcoeg Ba, ATTORNEYS. C. N. PETERS. Photo Lithographer, Washington. D. C. ...
The object of the present invention is to ... The invention chiefly consists in ... Upon being released the spindle is rotated back to its initial position through the ...
My invention relates to the construction ot' ... _Q_fâ_th_i_s invention, and consists of' a solid soft iron or steel bar, ... the pressure of the core upon its center, and.
The male and female flowers are borne either upon one spike or occasionally upon separate ones, and the roundish, fleshy fruit are of a pur plish hue, each ...
tus, to be also arranged at the auxiliary ex- series of binding-posts, 53 54 55, ... pi:. In order to provide for releasing the clock being the assuined starting point.
tact groups to form a common contact System, transfer switches adapted to cut in Said dupli cate contact sets alternatively into circuits, and 75 a single movable ...
circuits. Such a switch or circuit-changer is shown and described in patentissued July 1S,. 1SS2, to Theodore N. ... specification, Figure 1 is a diagram showing.
Be it known that I, ASAHEL K. EATON, of. Brooklyn, State of ... The nature of my invention consists in the ... tral pole. Upon the same principle multipolar magnets.
p^v^Wmittavy (^xamittatiott-. A "preliminary examination," means a search among the ..... lawful Trade-Mark, may obtain registration and protection therefor upon ...
An Abridged Account, Historical and. Technical. ... Rome, a question likely to be pressed rudely upon ...... arrangement; but to this we answer that some H. A. Isaacs, the chairman. ...... Burmah; 5 to the Philippines and, 18 to the Dutch Indies.
depressing button K of that line fails to get a response. Subscriber at a station between the station call ing and the central office is using the line, or because the ...
the Norris Perers co., PHOTo-LTHQ., WASH1NGTON, d. c. ..... Wardly far enough to permit the tooth B° to be ...... 5S 60, in which event each group-connecting.
SPECIFICATION forming part of Letters Patent No. 573,884 ... Application filed September 16, 1893, Serial No. 485,700 ... Fig.2 is a plan view of a portion of Fig.
Section, Public Law 690, August 8, 1946. Patent expires August 2, 1966. (C. 179-18). 1. Claims. 1. ..... vided three relays 9, 10 and , which are mounted in series ...
chamber with a self-adjusting pin of carbon or metal convex upon the extremity in con tact with the plate, which pin is permitted to slide or drop upon the carbon ...
