US2719960A

US2719960A - Alarm sending system

Info

Publication number: US2719960A
Application number: US426790A
Authority: US
Inventors: Albert E Bachelet; George A Pullis
Original assignee: Bell Telephone Laboratories Inc
Current assignee: AT&T Corp
Priority date: 1954-04-30
Filing date: 1954-04-30
Publication date: 1955-10-04
Anticipated expiration: 1972-10-04

Description

Oct. 4, 1955 Filed April 30, 1954 F G. OENODULTOR ALARM CENTER A. E. BACHELET E-r A1. 2,719,960

ALARM SENDING SYSTEM 2 Sheets-Sheet l A. E. AcHELEr Nm/TOPS mAH/Us By am ATTORNEY Oct. 4, 1955 A. E. BAcHELE-r ET A1.

ALARM SENDING SYSTEM 2 Sheets-Sheet 2 Filed April 50, 1954 N .Qs

A. E. AcHaEr NVE/W05 @.A. PULL/.sr

C. han@ United States Patent @nice 2,719,060 Patented Oct. 4, 1955 ALARM snNDrNG SYSTEM Albert E. Bachelet, `New York, and George A. Pullis,

Riverdale, N. Y., assignors to Bell Telephone Laboratories, Incorporated, `New York, N. Y., a corporation of New York Appncarisn Apr-i130, 1954, serial No. 426,790

s Claims. ((31.340-163) This invention relates to alarm signaling and remote control systems and has for its object to facilitate the indication of alarm or other conditions at remote signalling stations and the transmission of orders to such stations.

Elaborate systems have been designed formain signaling routes but such arrangements are not economical for small branch routes having relatively few stations thereon.

ln accordance with the present invention a simple, relatively inexpensive, signaling system is provided, employing a rotary stepping switch at each station, with means controlled over the switches to identify a station in trouble and the nature of the trouble.

Further means is provided by the directive controlof the station switches to select a particular` s tation and to register a specic order at that station.

These and other features of the invention will be more clearly understood from a consideration of the following description read in connection with the attached drawing in which:

Fig. 1 shows the equipment at the alarm center; and

Pig. 2 shows the equipment at the unattended station.

ln general, the system includes an alarm center (Fig. 1) and five unattended stations l(Fig. 2) connected by` order wire 100 which may be a physical line ormay be a particular channel of the signaling system. Signals are transmitted by means of voice frequency alternating current, only two frequencies being employed, that is, one

frequency, for example 1300 cycles, bythe alarm center and the other frequency, for examplelSOOcycles, by` the unattended stations. As shown `in Fig. 2, each unattended station has a plurality of alarm relayssuch as relay ALI and a common alarm relay A3. When an alarm condition arises, a pulse of the 150G-cycle frequency is transmitted over the order wire causing an alarm indication at the alarm center. Each station also has a rotary switch, which may be operated under the control of thel alarm center, and the common alarm relay marks` one `of five station identifying terminalsinits associated switch to identify the unattended station.

Following the reception of `an alarm indication, the` only the transfer relay of the station, whose identifying` digit has been dialed, operates at the end of the` digit, since this relay is, in each station, connected to the terminal assigned to that station. The terminals correspond ing to those assigned to other stations are connectedto the windings of a set of lockout relayswhich open the circuit of the transfer relay whena digit `assigned to another station is dialed. The transfer equipment con- Cil nects the individual alarm relays to terminals of the switch and the attendant now initiates another scanning operation to identify the nature of the trouble. The transfer equipment also prepares a plurality of order circuits and the attendant may transmit an order following the identifcation of the trouble or by rst operating the transfer equipment and then dialing a digit corresponding to the desired order.

Assume now that an alarm condition at unattended station 3, lshown in Fig. 2, causes the connection of ground to conductor 200, completing a circuit from ground on conductor 200 through the winding of individual alarm relay ALL contact 1 of relay AL1, upper winding of common alarm relay A3, contact 4 of relay C, left winding of relay T to battery. Relays A3 and T operate in this circuit, relay A3 locking in a circuit from battery through its lower winding and over its contact 1 to ground through resistance R1. At its contact 2, relay A3 connects ground through resistance R1 to terminal 3 of brush 201 of the rotary switch SW3 to identify the station. Relay AL1 is marginal and cannot operate in series with the high resistance of the left winding of relay T. Relay T connects the station oscillator 206 over its contacts 1 and 2 to the order wire 100 and at its contact 3 closes a circuit from ground over contact 5 of relay C, contact 3 of relay T to battery through the winding of relay F. Relay F is slow to operate and after an interval connects battery to the upper winding of relay A3 in parallel with the left winding of relay T, thereby increasing the current flow through the winding of relay AL1 suciently to cause that relay to operate and lock to battery over its Contact 2. At its contact 1, relay AL1 opens the circuit of relays A3 and T, relay T releasing to terminate the alarm signal but relay A3 remaining operated in its locking circuit. Relay T in releasing also releases relay F.

At the alarm center the alarm signal passes through band-pass filter 101, which is tuned to the G-cycle frequency, amplifier 102 and demodula'tor 103 to the winding of relay R. Relay R, when deenergized, holds its contact 2 closed, holding relay S operated. When relay R operates, it opens the circuit of relay S, but relay S is slow to release and does not close its contact unless the signal continues for a sufficient length of time to indicate an alarm signal, thus preventing alarm indications due to noise and other transient conditions. When relay S releases, it operates buzzer B to indicate the arrival of an alarm.

The attendant at the alarm center now operates key CA to prepare for identifying the station and the alarm condition. At contact 4 of key CA a circuit from ground is closed over the pulsing contact of dial D to the winding of pulsing relay P, operating relay P. Relay P at its contact 2 closes a circuit for the magnet Step C which controls the rotary switch SWC. With key CA and relay P oper-V ated, the 1300cycle oscillator 105 is connected over

contacts

2 and 3 of key CA and contact 1 of the pulsing relay P to the order wire 100.

Each of the unattended stations responds to the 1300- cycle current in the same manner as station 3 of Fig. 2, where the current passes through the band-pass lter 203, which is tuned to the 1300-cycle frequency, amplifier 204 and demodulator 205 to the winding of relay A. Relay A operates in this circuit closing at its contact 2 an obvious circuit for relay B. Relay B is slow to operate so that it will not operate from transient conditions. After a period, say of two or three seconds, relay B closes an obvious circuit for relay C. Relay C at its contact 4 opens the circuit through the left winding of relay T and at its contact 5 opens the circuit of relay F to prevent the trans- 'mission of alarm signals during the time the unattended 3 station is receiving pulses from the alarm center. Alarms which originate at this time also cannot be locked in.

After waiting the necessary two or three seconds to permit the-conditions at -the unattendedstations to become stabilized, the attendant will dial the digit .to initiate a 'scanning operation to determine the station which originated/the alarm. `At each opening of the dial contact, relayP releases, disconnecting the I300-cycle current from `the'order wire andrreleasing magnet Step C to advance switch SWC one step. While'the dial operation has been shown as a simple interruption of the signaling current -it `will be iunderstood that 4any yother 4well-known methodof-removing the signaling'currentfrom the order wire/maybe employed.

The disconnection .of the i300-cycle .current at yeach openinglofthedial contact causes-relay A to release, completing a circuit-.over-its contact .1 and-contact 2 of relay C to battery Vthrough the -windings of magnet Step 3.and relay E. yMagnet .Step -3 is .energized to prepare switch SW3 ytofstepand relay E opens a `circuit which will be traced hereinafter. *In response-to the dial pulses, switches SWC and SW3 will vadvance in synchronism to positionl. When brush y201 isadvanced ktoits third contact, acircuit is closedlfromfground through resistance R1, contact Ztof relay A13, contact of relay TR, terminal 3 and brush 201, contactfofrelay D through the right winding of relay T to battery. vRelay T operates and, in the manner previously described, connects the station oscillator 206 to the order wire 100,- operating rel-ay R atthe alarm center. With key CA operated, the'operation of relay R closes a circuit from ground over contact 1 of relay R, contact 1 of key CA, `brush V104 of switch SWC, which atthis time will also be engaging its thirdcontact, winding of indicating relay l3to battery. Relayl3 operates and locks over its contact 1 toi ground overlooking key Land at its contact -2 lights indicating lamp L3 thereby indicating to the vattendant the identity of the `station which originated the alarm.

At station 3 the connection of battery through the winding of relay T to resistance-R1 in parallel with the lower windingI oft relay A3 reduces the current flow inthe locking winding of relay-A3 sufficiently to cause relay A3 to release. At the end of the digit, switch SW3vwill be left Oifnormaliniposition but with relay Aheld'operated the circuit'ofrelay E is opened and when that relayreleases, after anfinterval, it` closes acircuittrom` battery over contact y\2-of relay 1D,back.contact of .-relay E, contact 3 of relay TRA, contact 3 of relay TRB, vbrush.202\and its tenthterminahcontact y1.o'f relay ITR to ground through the winding.of.-slow-tooperate.relay SO. -Relay SO operates and closes a circuit from battery through the winding'of release magnet RLS3 to lground over .off-normal contact RON. "Magnet\RLS3 operates-in-this circuitto. restore switch .SW3to-normal. .Assoon as switch`SW3 leaves-its-terminal 10, relay SO releases. The'switchesat all of the unattendedfstationswill-be returned to normal in-fa similar manner.

When the dial D'returns to normal, switch SWC will berestored to its normalposition by releasemagnet RLS which `is operatedin a-.circuit frombattery through -its winding over off-normal contact ONC, normall contact of dial D and Contact 5 of key4 CA.

As :previously stated, -thecommonalarm relay such as relay `A3-connects resistance ground to a-particular terminalfofits stationswitch which will identify-the ,station. `That is,\in.station.1,1the resistance ground would beV connected .over a. normalfcontact. ofthe 1a ssociatedtransfer relay to terminal 1 of the switch at that station. In stationlz, the resistance ground would be connected to terminal'Z of theV switch, etc. `vIn 'the remote event that alarmsfrom. more'thanone station overlap, the signaling operation "above described would cause 'the corresponding plura'ltycf' indicating 'relaysto 'operate and lock.

4In order toY identify therparticular yalarm condition, `the attenrlant will-select'the station identified by the indicating 4 lamp, in this case station 3, by dialing the corresponding digit. As a result switches SWC, SW3 and all of the other station switches will be advanced simultaneously to their positions 3 in the manner previously described.

At station 3, when relay E releases at the end of this digit a circuit will be closed from battery over contact 2 of relay D, contact of relay E, contact 3 of relay TRA, Contact 3 of relay TRB, brush 202 in position 3, contact Y1 of relay TRB, contact 1 of .relay TRA to ground through'the winding of transfer relay TR. Relay TR operates in this circuit and locks .over its contact 14 to battery over contact 3 of relay C. Relay TR closes a circuit for slow-to-operate.relaySO from battery over contact '2 of relay D, contact of relay E, contact 2 of relay TR to ground through :the 'winding of relay SO. Relay SO closes the previously traced circuit for operating release magnet RLS3 which restores switch SW3 to normal. SRelay SOremains'operated under the control of relay E. At the otherunattended stations, since their relays TRl arenot operated, relay SO is not operated and theswitch is notrestoredto normal at this time.

With relay TR `operated,\the front contacts of a maximum of'tenindividual alarm relays, such as relay ALI, are .connected to the kcorresponding terminals of brush 201. The operated-one'or'ones of the alarm relays connect-.ground vto their front contacts and thence to the corresponding -terminalsof brush l201. Assuming that relay -ALI .is `operated alone, ground is connected to terminal 1 of brush 201. At the alarm center, switch SWCwas `restoredtto .normal .by the return of the dial and `.the attendant, having'identied and selected the station which originated the trouble, will momentarily operate locking key `L to release indicating relay I3 and extinguish lamp .L3 to,prepare for identifying the individualalarm oralarrns. He will then dial the digit 0 causing switches SWC and SW3 to advance to lposition 10. As soon Ias relayE operates in response to the iirst pulse, thecircuit of relaySO is opened and that relay releases. When brush 201 engages its irst terminal` groundis connected over contact 3 of relay AL1, contact 13 of relay TR,-terminal 1 and brush v201, con tact3 of relay Dto battery through 'the right winding of relay "T, operating relay .T to transmit a pulse of 1500- cycle current over the .order wire in the manner previously described. At the alarm center relay R operates and closes -a circuit fromground over its contact 1, contact 1' o'f'key CA and brush v104 to the winding of the relay,`like relay I3, which is-connected to terminal 1 ofbrush 1021. .This relay operates, locking under the control ofkey `L and lighting the corresponding lamp. At the-end of the digit, relay .E releases, reclosing the circuit of relay TSO to restore the switch SW3 to normal.

Relay`TR also prepares station 3 to receive orders. Ifthe attendant 'wishes to transmit an order following the identification of the trouble, he `will then proceed to dial the digitcorresponding to the necessary order. Switches SWCand'SW3 advance in response to this digit, any indications .receivedover switch SWC being disregarded at-ths time. Assuming that the digit 1 is dialed, switch SW3 'advances brush'202 to its first terminal. When relay yE releases at the end of the digit, a circuit is closed from battery over contact 2 of relay D, contact of relay E. contact'3 ofrelay TRA, contact 3 of relay TRB, brush 202.and its 'first terminal, contact 15 of relay TR to ground throughthe wndingof order relay ORI. Relay'ORl operates in'this circuit to perform the required function. After an interval measured'by the operating time of relay SO,"switch SW3 will restore to normal.

Having transmitted the order the attendant will relea'se'key CAto restore the alarm center and the unatterded stations `to normal.

4rhe release of key CA disconnects oscillator 105 from the order'wire and permits relays'A to release in all stations 'followed by relaysB and C. Relay C at its contact 3 opens the circuit of relay TR causing that relay to release in turn releasing relay SO'. With relays A and C released, acircuit is closed from ground over contact 1 of relay A, contact 1 of relay C, contact 2 of oif-normal` springs RON to battery through the Winding of relay D. Relay D operates and in the non-selected stations closes a circuit from battery through release magnet RLS3, contact of relay D to ground over contact 1 of off-normal springs RON. The release magnet operates to restore the switch, like switch SW3, to normal at which time the olf-normal springs open. Relay D at its contact 2 disconnects battery from brush 202 and at its contact 3 disconnects relay T from brush 201 to prevent any false operations during the return of these two brushes.

Relays TRA and TRB are furnished to positively prevent the false selection of more than one station. At each station, the relay which corresponds to relay TR is connected to the terminal of brush 202 which corresponds to the station number and the windings of relays TRA and TRB are connected to the other four of the station identifying terminals of brush 202.

To illustrate the function of relays TRA and TRB, assume that the attendant at the alarm center wishes to select some station other than station 3, for example station 2. The connection of the l300cycle current to the order wire causes the operation of relays A, B and C as previously described and relay A responds to the dial pulses to operate magnet Step 3 and advance switch SW3 to position 2. At the end of the digit, relay E releases and a circuit is closed from battery over contact 2 of relay D, Contact of relay E, contact 3 of relay TRA, contact 3 of relay TRB, brush 202 and its second terminal, over contact 18 of relay TR to ground through the lower winding of relay TRA. Relay TRA at its contact 1 opens the circuit of relay TR preventing the operation of that relay if brush 202 is brought to rest on terminal 3 as a result of an order sent to station 2. At its contact 2 relay TRA locks in a circuit from ground through its lower winding over its contact 2 through resistance R2 to battery at contact 3 of relay C. With relay C operated, the circuits of relays T, A3 and F are opened so that none of these relays can operate while the alarm center is associated with station 2. Therefore terminal 3 of brush 201 cannot be grounded by relay A3 and, since relay TR is not operated, none of the terminals of brush 201 can be grounded by an alarm relay such as relay AL1. This will also be true of stations 1, 4 and 5 so that no alarm signals can be transmitted by other than the selected station.

What is claimed is: y

l. In an alarm sending system, a main station, a plurality of subsidiary stations, a channel connecting said stations, a stepping switch at each station, each of said switches having station identifying sets of terminals individual to each of said subsidiary stations and a plurality of other sets of terminals, a plurality of trouble registering devices at each of said subsidiary stations, means under the control of any one of said trouble registering devices to mark the set of terminals individual to that station in the switch at that station, means under the control of the main station to step all of said switches simultaneously any desired number of steps, means operated when a switch is stepped over a marked one of said terminals to identify the marking station to said main station, a transfer relay at each subsidiary station connected to one terminal of the set individual to that station, means to operate said transfer relay when said switches are stepped to the set of terminals individual to a station, means under the control of said transfer relay to connect said trouble registering devices to said station identifying terminals and to said other terminals, trouble identifying devices at said main station, and means under the control of an operated trouble registering device to operate the corresponding trouble identifying device at said main station.

2. In an alarm sending system, a main station, a plurality of subsidiary stations, a channel connecting said stations, a stepping switch at each station, each of said switches having station identifying sets of terminals individual to each of said subsidiary stations and a plurality of other sets of terminals, a plurality of trouble registering devices at each of said subsidiary stations, means under the control of any one of said trouble registering devices to mark the set of terminals individual to that station in the switch at that station, means under the control of the main station to step all 'of said switches simultaneously any desired number of steps, means op erated when a switch is stepped over a marked one of said terminals to identify the marking station to said main station, a transfer relay at each subsidiary station connected to one terminal of the set individual to that station, means to operate said transfer relay when said switches are stepped to the set of terminals individual to a station, means under the control of said transfer relay to connect said trouble registering devices to said station identifying terminals and to said other terminals, trouble identifying devices at said main station, and means operated during a subsequent stepping operation of said switches under the control of an operated trouble registering device to operate the corresponding trouble identifying device at said main station.

3. In an alarm sending system, a main station, a plurality of subsidiary stations, a channel connecting said stations, a stepping switch at each subsidiary station, each of said switches having station identifying sets of terminals individual to each of said subsidiary stations and a plurality of other sets of terminals, a plurality of trouble registering devices at each of said subsidiary stations, means under the control of any one of said trouble registering devices to mark the set of terminals individual to that station in the switch at that station, a stepping switch at said main station, trouble identifying devices connected to the terminals of said main station switch, means under the control of the main station to step said main station switch and all of said subsidiary station switches simultaneously any desired number of steps, means operated when a switch is stepped over a marked one of said terminals to transmit a signal to said main station to operate the trouble identifying device connected to the corresponding terminal of said main station switch to identify the marking station to said main station, a transfer relay at each subsidiary station connected to one terminal of the set individual to that station, means to operate said transfer relay when said switches are stepped to the set of terminals individual to a station, means under the control of said transfer relay to connect said trouble registering devices to said station identifying terminals and to said other terminals, and means under the control of an operated trouble registering device when said subsidiary station switch passes over the terminal to which said operated trouble registering device is connected to transmit a signal to said main station to operate the trouble identifying device connected to the corresponding terminal of said main station switch.

4. In an alarm sending system, a main station, a plurality of subsidiary stations, a channel connecting said stations, a stepping switch at each station, each of said switches having station identifying sets of terminals individual to each of said subsidiary stations and a plurality of other sets of terminals, a plurality of trouble registering devices at each of said subsidiary stations, means under the control of any one of said trouble registering devices to mark the set of terminals individual to that station in the switch at that station, means under the control of the main station to step' all of said switches simultaneously any desired number of steps, means operated over a marked one of said terminals to identify the marking station to said main station, a transfer relay at each subsidiary station connected 'to one terminal `of ithe ,set vindividual to that station, means to operate said transfer relay when said switchesaresteppedto the set `ofterminals individual to'a"station',means under the 'control of said transfer .relaytoeonnect *saidtroble registering devices to said station `ri'c'lentfying 'terminals and to Asaid 'other vterminals, troble identifying 'devices l'at Vsaid main station, means unrl'er'fthe control of an operatedtrouble registering device to operate the 'corresponding trouble identifying device at saidmain station,lockout` means at each station 'conneeted to'the -station lidentifying terminals individual to oth'erfstationsg'and means under the control of said lockout meansto' prevent`t'h'e operation of the transfer relay atfmorefthan'one'station f5. "In an'alarmsending-system, 'a main station, a'plurlity of "subsidiary stations, ka channel connecting 'said stations, fa 'steppingswitch at each station, each of `said switches ihavingstation YVidentifying sets of terminals individualtto'each of said subsidiary stations anda-plurality o'f'o'ther'sets of terminals, a plurality of ltrouble registering devices at each ofsaidsbsidiary'stations,means under the control'of any one of r said trouble registering devices to'fmark the set of terminals individual to that station in the y'swith'at that station, means under the control of ythe main stationtostepall-of said switches simultaneously any-desired number of steps, means operated over a 8 marked oneof said terminalsftoidentify the marking station 'to saidl maintstation, valtransfer relay at each subsidiary station Yczonnec'ted 4to one t'errriinal of the setin* dividualy to that station,.means to.operate said transfer relay when sai'd switches are stepped to the set'of terminals indivi'dualtoV a station, means 'funder Athe control o`f said transfer rl'ay .to connectsaid trohle registering devices to said stationfidenti'fying terminals and torsaid other terminals, trobleidentifyingidevices Aat, said main station,

means ,under 4the control ,of an'rop'erated trolle register? ing device to operate the corresponding trouble identifying device at :said rmainl station, 4lookout meansr at each station connected to thefsttion'identifying terminals individual to other stations, means to operate saidloc'kout means vwhenra subsidiary station. switch is stopped on one of said terminals'indivi'dual to otheristations, and means responsive to the operation f said'lockout means to prevent the operationof the Atransferrelay atthat station.

.ReerencesCite intheflle oftl'i'is patent lUNIfI'ED 'STATES PA-'PENLFS 1,632,106 Zogbaum June 14,1927 2,56722'6 'McWlii'rter et al Sept. 11, 19511 2,'607QS43 Hearn .et al. lAug.1`9, 1952