US2405618A - Permutation code data transmission system - Google Patents

Description

Aug. 1-3, 1946. E. M. SMITH 2,405,518

PERMUTATICN CODEDAI'A TRANSMISSION SYSTEM Filed May 1-2, 1943 5 Sheets-Sheet 2 FIFTH FOUR TH IELECT/NG I cm can T mmo :eu'c TING CIRCUIT BY Maw A TTORNEV z wmw v Filed May 12, 1943 5 Sheets-$hee t 3 AT O NE "9% R 0 T- l J 5% N W e M M I E V a m B mg SX W r P Y Wu." mm E I HI. pkb. MR. km? wv wa wow MN? m Rum Sm v 2 k v f www wm 3 2 L J 3.2 m w m 8 RM 62 9v QR Kw m LAM 7 $5 33 .figk 3m 3 .2893 .QQ. wmw & T: mNM/a wamu wwuwm v .1. g, Q? \NM b v2 F RT v N3 a w R L Aug. 13,1946. 'E. M. SMITH fl fi PERMUTATION CODE DATA'TRANSMISSION SYSTEM Filed May 12, 1943 5 Sheets-Sheet 4 /N VE N TOR E M SMITH 5v a.

A Tram/EV Patented Aug. 13, 1946 PERMUTATION coma DATA TRANSMISSION YSTEM Edward M. Smith, Montclair, N. 3., assignor to Bell Telephone Laboratories, Incorporated, New York, N. Y., a corporation of New York Application May 12, 1943, Serial No. 486,652

Thisinvention pertains to high speed permutation code signal data transmission systems and to telemetering systems.

More particularly this invention i an improved permutationcode signal data transmission system or telemeteringsystem requiring a minimum of conductors or transmission channels interconnecting the data measuring'station and receiving station for designating any of 3,000 observations or measurements ahnost instantly.

By means of the data transmission or tele metering System of this invention only five conductors or transmission channels are required to interconnect the observing and receiving stations to define almost instantly any of 3,000 observations.

' The invention may be employed to define any measured quantity where the quantities to be measured are progressively increased. In this present embodiment the invention is arranged to cover a'rangeof 3,000 observations or measurements. It is assumed that the quantity measured extends over a range from zero unit to thirty units and the system defines the measurement tothe nearest'hundredth of a unit. The system maybe employed to transmit permutation code signals defining the readings of measuring meters used for anypurpose.

A feature of this invention is an arrangement for impressing permutation code signals which completely define a number having fourdigits on a single five-channel telegraph signal circuit at the same instant.

A further feature of this invention is the employment at the receiving station of five separate relay selecting circuits for the translation of the permutation code signals defining the digits in the different places in a multidigit number corresponding to observed or measured data which selecting circuits are controlled simultaneously by a single five-channel permutation code transmission circuit common to all five selecting circuits.

A further feature of thi invention is an arrangement for impressing permutation code signals which completely define a number having four digits on a single five-channel telegraph signal circuit at the same instant and thereafter impressing said signals on five separate independent selecting circuits.

A further feature of this invention is an arrangement for impressing each of the five elemerits of a five-element permutation code signal individually through a separate one'of five transmission channels on five separate selecting cir- 5 Claims. (Cl. 177353 cuits simultaneously, 'each of said selecting circuits being capable of making an independent selection and all selections cooperating to define the separate digit of a four-digit number simultaneously. I

A further feature of this invention is an arrangement of five separate selecting circuits controlled by five transmission channels serving said circuits in common; which arrangement includes means for impressing permutations of two electrical condition from each ofv the five channels on the first of the selecting circuits to indicate the setting of a measuring instrument to the nearest hundredth of a unit in each of eight zone into which the full unit is divided, which arrangement includes also means for controlling the first selecting circuit at times by means of one of the five channels only so that it indicates the first hundredth of a unit setting of a measuring instrument in each of the eight zones at such times in response to a condition impressed on it by the one channel, while a second selecting circuit is controlled by means of conditions impressed on it by the other four channels to indicate the particular, one of the eight zones in which the measuring instrument is set. A further feature of this invention is an arrangement for maintaining four of five selecting circuits in a particular fixed condition in response to an electrical condition impressed on each of four out of five transmission channels to completely define three of the digits in a fourdigit number While the fifth selecting circuit is controlled by an electrical condition impressed on the fifth channel only to determine the digit in the fourth position of the number.

General description In the present invention it is assumed that any quantity in a thirty-unit range is measured to the nearest hundredth of a unit. The measurements are translated into various code combinations of settings of three sets of cams. One set of cams establishes twenty-five permutation to define units, groups of five units and groups of fifteen units. The cams control contacts each of which is arranged to impress either of two electrical conditions on a corresponding one of five conductors or transmitting channels connecting the measuring instrument located at an outlying observing or measuring station to receiving, selecting; and indicating apparatus at-a central receiving or metering station. The permutation code signals are impressed on five sets of polar receiving relays which are operated in a manner to correspond to the code. The polar receiving relays are in turn connected within the receiving station to five separate-selecting cir-.-- cuits by means of five local transmission chana nels. The five selecting circuits are controlled simultaneously by the five channels.

The selecting circuits are arranged in the gen eral form of fan relay circuits modified; per this invention, 50 that, in addition to the usual selections made by the cooperation of the various relays in each fan circuit under the influence of a number of transmission channels the relay at the apex of the fan in each selecting circuit may at times make a single selection in response to an electrical condition impressed on onev channel only, whil e the selection remains, unaffected by the conditlons impressed on th other channels.

By this expedient it is possible to make a selectionin each of a number oi selecting circuits to define particular digits, such a the zero digits for example, in certain places of the, number, while another selecting circuit responds simutlaneously to permutation code signals impressed on less than five,of the channelsto indicate a digit in, a

igher'v l fi z ace in thcnumb n.

' The selecting circuits; cooperate to light four numbered lamps to indicate the four digits corresponding to the setting of the measuring instrument, thus identifying. the measured quantity within the thirty-unit range to the nearest hundredth of aunit, d The speed. of operation of the apparatusof the invention herein compares favorably with the speed of operation of data transmission apparatus or teleinetering apparatus. operating on the voltage or resistance balancing methods'of, operation. The numberof transmission channels required is the minimum for a permutation code signal transmission'system capable of as many m a r n t one im e sed ve r smission channels tp; operate five sets of polar receiving relays, at the receiving station. Five of the polar relays, one in eachset, impress the permutation code. signals by means of five local channels within the receiving station on. the selecting circuits. All five of the transmission channelsinterconnecting the polar receiving relays and the selecting circuits are connected to one of the fiveselecting circuits only. Four of these five transmission channels are connected to .a second selecting circuit; three ofthem are connected also to a third selecting circuit; two to a fourth selecting circuit and one to a fifth selecting circuit.

In the first selecting circuit there are five switches for changing the selecting paths through the circuit. In the second selecting circuit there are; four switches for this purpose. In the third, second and first selecting circuits there are three, two and one switch, respectively. A permutation code signal containing five signal elements is impressed on the channels to the five selecting circuits simultaneously. If a change is required in a digit in the first right-hand position of the number only or in the first two positions for a change within the same eighth of a unit zone, only one selecting circuit, namely, the one having five switches, will respond while the other four selecting circuits remain locked. If a change is required in a digit in the second right-hand position in the number corresponding to a change between eighth, of a unit zones and no changeiis required in a digit in any higher valued, position of the number, the second selecting circuit is arranged to respond to four elements of thefiveunit code, while the third,v fourth and fifth selecting circuits, remain locked. Sincev each such transition involves also a change in the righthand digit of the number, such a transitionwill be made by the. fifth selecting circuit under control of one of the five channels. only. In. general the various selecting circuits are arranged in cascade so that when changes are required in higher valued positions in the number, a fewer number of transmission channelscontrol aselecting fan circuit with a correspondingly fewer number of switches to efiect the transition while an electrical condition, impressed. onv singl channels, not employed, in effecting the transition in the digit in the higher. valued positionof the number, effects a transition in each selecting fan circuit for each lower valued digit involved.

At all timesfiyerelement permutation code signals are. being. transmitted by the cam controlled contacts at the receiving station and retransmitted by the corresponding five polar receivingrelays at thereceiving. station. All fiveelements are employed at times. in setting the switchesof the hundredths of a unit selector only tov indicate the. measuring instrument setting within each eighth divisions of a. unit tov the nearest hundredth of a.-unit, At such times the selectors for the higher valued settings are locked in. the last position in which they were set. At other times as determined by. the value; of the measured quantity, the conditions of four elements of, the fiveelement code will set theeighth of a unitselector to indicate the eighth of a unitsettings. At such times one switch in the selector for the hundredths. of aunit. within each eighth of a, unit will be controlled by the electrical condition of the fifth element. of thecode only to. select the lowest value hundredth of a. unit in each eighth of a unit Zone while the selectors for the higher valued digits will be, locked in the last position inwhich they were set. At other times; as required, the electrical condition of three, elements of the five element code will set the. switches; in the selector for the indicator defining the1 digit in the units position or the firstposition; to the left of the decimal point. A single switch. of the four switches in the selector for the eighth of a unit selection will meanwhile besetby theelectrical condition impressed on one-channel'onlyto select all thirteen indicators in the firsteighth of a unit zone. A single switch of; the five switches lamp indicating the digit in the tens position or the second place to the left of the decimal.

The invention may be understood from the following'description when read with reference to the associated drawings in which:

Fig. 1 shows three sets of cams arranged in horizontal rows, The cams are assumed to be controlled by a measuring instrument, not shown, at the transmitting station. The cams control electrical contacts which set up and transmit permutation code signals over five electrical transmission channels connecting the observing or measuring station to the receiving station where they are impressed on five sets of polar relays, the

armatures of which are set in accordance with the code in response to the received signals. The receiving relays impress the received code signals on five selecting circuits per Figs. 2 and 3.

Fig. 2 shows the upper portion and Fig, 3 the lower portion of a selecting system comprising five separate relay selecting circuits resembling fan circuits which respond to the code signals retransmitted from the polar receiving relays in Fig. 1 to translate the codes received by them from the cams into lamp selections in the indicator circuit per Fig. 4.

Fig. 4 is an indicator circuit comprising essentially a bank of one hundred lamps, shown at the right, which indicates the setting of the measuring instrument to the nearest hundredth of a unit. The figure shows also a bank of ten lamps arranged in a vertical row which correspond to the numeral in the units position or in the first position to the left of the decimal point. To the left of the group of ten vertical lamps is a group of three lamps arranged also in a vertical row which correspond to the numeral in the tens place or in the second position to the left of the decimal point. Only 3,000 selections are made by the system of the invention in its present form so only three lamps are required for the tens digit. It is to be understood, however, that the system of the invention is capable of unlimited expansion row of cams so that codes defining the digits in the higher valued positions in the number may be transmitted as required.

Fig. 6 is a chart showing the permutation code signals set up by cams IOI and I! to H0 in Fig.

1 to define the digit in the second right-hand position which in this case corresponds to the eighth of a unit setting of the measuring ins-trument and shows also the relative times at which cam I I I connects ground through to the top horizontal row of cams for transmitting codes definare set up are not all different, however.

each of the first thirteen of the twenty-five positions, thirteen different permutation codes are I 6 ing the digit in the two left-hand positions of the number when required.

Fig.- 'I is a chart showing the permutation code signalsset up by cams IIZ, I01 and H3 to H5 in Fig. 1 duringa revolution to define the digits inthetwo left-hand positions of a number cor responding to a'measurement which in this case corresponds to the digits in the units and tens position in the number or in the first and. second positions to the left of the decimal point.

Fig. 8 is a diagram showing the manner in which" Figs. 1, 2, 3 and 4 should be arranged, each in relation to the other to form an operative system.

Detailed description Refer now to Fig. 1. Cams IM to I 00 are rigidly secured to a, first shaft, cams I 01 to II I to a second shaftand cams H2 to I I5 to a third shaft. As the measuring instrument, not shown, is rotated, the three shafts which are connected to the measuring instrument by the gear system in an convenient manner are rotated to maintain the following relationship. As the measuring instrument changes through the full thirty-unit range cams II 2 to II 5 turn through one revolution. As the measuring instrument changes through a range of one full unit, cams I01 to III turn through one revolution.

Cams H3 to H5 are so arranged that as they rotate through a complete revolution they set up thirty permutations of contacts I10 to I13 to define each of thethirty full units. The peripheries 0f cams I I2 to I I5 are arranged in two levels. Where the periphery of the cam is raised the corresponding contact is open. Where the periphery of the cam is depressed the corresponding contact is closed. Cams I01 to H0 are arranged so that as they rotate they operate their respective contacts to set up eight difierent permutations of open and closed circuit conditions to define eight different eighths of a, unit changes in setting of the measuring instrument within each unit. Cam'I I I is a ground supply switching cam employed to supply ground at the proper intervals to the top row of cams.

Theperipheries of cams I01 and III each have two levels. Where the periphery of cam I 01 is raised, contact I62 is open and where it is normal contact I62 is closed. Where the periphery of cam II I is normal contact I09 is open and where it is raised contact I08 is closed. The peripheries of cams I08, I09 and H0 each have three levels. At their highest level these cams close their respective contacts I63, I65 and I01. Where the peripheries of cams I08, I09 and H0 are normal their respective contacts I63 to I68 are all open. Where the peripheries of cams I08, I09 and H0 are depressed, their corresponding contacts I60, I66 and IE8 are closed.

As cams IOI to I05 rotate through one revolution they set up twenty-five permutations of open and closed circuits conditions to define each one of the twenty-five different hundredths of a unit settings of the measuring instrument within each quarter of a unit. The twenty-five codes which For transmitted to define thirteen different hundredths of a unit settings of the measuringinstrument. Then twelve of these codes are repeated to define the remaining twelve diiierent hundredths of a unit settings of the measuring instrument in each quarter of a unit. Reference to Fig. 5 shows that in repeating the codes, the

:cod'e defining the sixth hundredth 20f la'unit setting in the first half revolutionof cams l! :to 1051s :notzrepeated in the second halfvrevolution of these cams. Cam H16 .is a ground supply switching cam "for; the two upperr'ows of cams.

.'Ihe;peripheries of cams NH and H16 are arranged :in' two levels. Where the ,.-periphery of cam :10! is raisedcontact i] is closedand where .itisnormal contact I52 is'closed. Where the periphery of .cam 406 is raised, contact [BI is closed and where it is normal, contact I51 is open. FI-hegperipheries of cams 02 to I05 are .arranged :in three levels. The raised. levelcloses contacts I53, I55, I51 and I59. At the normal level of the peripheries of calm I02 to I05 all of the corresponding contacts reopen. Where the peripheries or cams I02 to I05 are depressed *c0ntacts154, |56,i|58f331ld1$0 are closed.

Referto Figs. 5, '6 and .7. TIn'Fig. S'thereare five horizontal rows "of cross-hatched and blank rectangles corresponding "to the "open and closed circuit conditions of the right hand :contacts associated with cams l0! .to N5, respectively and thedefthand contact of cam "Hit. In'Fig. '5 there 'are also twenty-five vertical columns numbered 500 to 524. Each vertical column represents a combination of open 'and closed contact conditions of contacts 152, 1.54, 1'56, I58 and I60 controlled by cams |U| "b0 105, respectively. Reference to vertical column .500 indicates that five of the rectanglesinthe vertical .row corresponding to cams l0! to-H35 are blank,'.while the rec- 'tang'l'e correspondingto cam I 06 :is cross-hatched. The .blankcondition"of'the'rectangles corresponding to-cams L0! to 105 indicates'thatitheir associatedright handcontacts [52 1'54, J56, 158 and 160 "are 'open to form the permutation code for the .90 unit position. In'tliis position cam 10 closes its corresponding contact 16! to connect ground to the 'upper horizontal row of cams. 'Thisis indicatediby the fact that horizontal .row

lfis is'cross-hatohed in vertical row '500.

Thecrosshatched and'b'lank rectangles in .ver- "tical rowSOlin. Fig. "'5 "indicates that contacts I52 associated with cam'lill and I56 associated with cam I03 areclosedand contacts 154, [58 and 160 associated with 'cams I82, I04 and 106, respec- "tively, 'are open "to form the pennutation code for the .0! unit. "Vertical cdlumns Z5021to .524 Show the codes tor the other "twenty-three positions in each quarter of a .unit set up .during a revolution .of'th'e. bottomfhorizontal row of cams.

In Fig. 6 there are seven'horizonta l rows correspondingito icam 1'0] and it'll! .to 1].! and eight vertical rows numbered 601] to 5&0? corresponding 'to the eight divisions of the peripheries .of these came. The permutation codes for each of the "eight unit divisions are indica'ted'in the eight vertical rows 'of'the top'fivelhor iznntal rows. The horizontal row corresponding to cam 1H! indicates that .contact l as .is closed .tosupp'ly .ground to the tophorizontal row ofcams whilethe code corresponding to the firsteighth of .a .unit divi-- 'sion, or. more exactly for'the .zone fromJlG .to. .13, is'being transmitted by them'i'ddle row of cams.

Fig. '7 shows fivehor'izorital rows one for each of-cams 1 IE to H5, inclusive ,andjthirty vertical "rows to define the codes 'foneach of the thirty full'unit settings.

Five conductors L'IBfl to I84 connect thecode cams at the measuring station to the polar receiving relays at the receiving station. It is pointed outthat, 'in placelo'f thefive conductors, alternating current channels whichmay Lbe .five carrier -current channels may be employed. The

-every .instance.

grounded at the-measuring station and for the other condition the circuit is open. When any circuit -isfgrounded the :armatures'oi the corresponding polarreceiving relays at the receiving station are operated to their respective lower ,positions. When the transmitting channel is open the armatures'of these relays areactuated upwardly due to the effect of current in their biasing windings. Five-element two-condition permutation code signals are transmitted in The armatures of each of the relaysconnected to channels 180 to I84 .are .set in .either of their two positions in .response to thecode signals.

.In response to the five-element code signals .fromthe cam controlled contacts either positive or negative battery is impressed through the armatures of the fiverelays H6 to on the selecting circuits.

As heretofore mentioned, there are five separate selecting circuits. All five of the five- .e'lemen'tsignals are not impressed on:each of the selecting circuits. Reference to Figs. .1, 2 and v3 shows that the .armatures of allfive code receiving .relays MB to l 20 :are connected only .to the first selecting circuit shown in Fig.3.

'While codes definingthe hundredths of a unit arebeing transmitted, all five of the sets-of relay switches in .the first selecting circuit are set in position. "Theselectionsintheother four selecting circuits are maintained .due to locking arrangementsQin the circuits while the hundredth codes are being transmitted into the first select- .ing circuit. When the setting .of the measuring instrument involves the transmission of codes requiring a new selectionlby the second selecting circuit, the second selecting circuitis conditioned to respond. Only four of the 'fiveelements of the five-unit code .are impressed .on the four switches .in the second selecting circuit at .suoh times. The fifth element of the code sets the switch nearest the apex .of the firstseleoting cir- .Clllt simultaneously 'to effect a selection by a single switch only in the first selecting circuit at such time.

When the measured data involves a change in aselection'by the third selecting circuit and .no change .in the fourth and fifth .selectingcircuits,

"the selections last madeby the fourth and fifth selecting circuits are maintained by lokingarrangements in the circuits. iThree signal ele- 'rnents of .thefive-unit .code areimpressed on the third selecting circuit to .set three relay switches therein. L'Ihe Tfourth signal .element is impressed on the second selecting circuit only and a .fifth signal .element isimpressed :on the first selecting circuit only. "In [the first .and second selecting circuits the single signalelement sets one switch .onlyin-each selecting circuitlto make an independent selection .in each to define the lower valued digits simultaneously.

When .two signal elements are employed to effect a change in the fourth selecting circuit the firs't,.second and third elements-of the .fiveelement .code control the single switch nearest the apex in the first, second :and third selecting second, third and fourth signal elements of the five-element code control the single switch nearest the apex in each of the first, second, third and fourth selecting circuits to effect a selection in each by means of the single switch alone.

The cams, contacts and relay armatures in Figs. 1, 2, 3 and 4, are shown in the condition for the transmission and reception of code signals corresponding to the zero setting of the measuring instrument. The corresponding cam conditions are shown in vertical columns 500, 600 and 700 in Figs. 5, 6 and '7. For this condition a circuit may be traced from ground I29 through contact IOI, contact I69, contact I I0, contact I5I and the windings of relays I2I and H6 in series to battery operating the armatures of relays I2I and H6 to their lower positions. The circuits extending through the windings of relays I25, I22 and H1, I21, I23 and H8, I28, I24 and H9,

Operation of first selecting circuit When the armature of relay H5 engages contact I 30, a circuit may be traced from negative battery, through contact I30, armature of relay H6, conductor 308 and the windings of relays SM and 302 in series to positive battery. For this condition the armatures of relays 30I and 302 will be actuated to their lower positions. When the armatures of relays II! to I20 are actuated to engage their upper contacts I33, I35, I 31 and I 39, positive battery is connected through their respective armatures, conductors 350, 352, 353 and 354 and the windings of relays 303 to 3| 4 to positive battery. Under this condition, the armatures of relays 303 to 3! in the first selecting circuit will be operated to engage with their upper contacts due to the efiect of current in their biasing windings. The armatures of all of the relays in selecting circuits 2 to 5 will be locked in the position indicated for reasons which will become apparent below.

Under these conditions, a circuit may be traced from ground through the armature of relay 3!, contact 3II, armature of relay 303, contact 3I9, armature of relay 300, contact 32I, armatureof relay 302, contact 360 and conductor M to conducting ring 400 in lamp bank 050 in Fig. 4. Ring 050 is connected in parallel to the inner terminals of lamps 00, I3, 25, 38, 50, 63, I and 88. This results in a selection of eight lamps.

The lamps in lamp bank 450 are divided into eight groups. Eight lamps, one in each group have been selected. It is now necessary to select a particular one of the eight lamps. This is performed by connecting battery to the outer terminal of some particular one of the eight groups Y into which the lamps in indicator bank 450 are divided. With the armatures of the relays in the second selecting circuit, shown at'the bottom of Fig. 2, arranged in the positions indicated, a circuit may be traced from positive battery, through the armature of relay 20!, contact 225, contact 2H and conductor 400 which connects to the bank of lamps numbered 00 to I2. As a result of this, since battery is connected to the outer terminal of only one of the eight lamps ing the contacts of relay 023.

10. to the bottom terminal of which ground is connected, lamp 00 only will be lighted.

This indicates that the measuring instrument is set at the moment in the .00 hundredths of a unit position. The particular full unit position in which the measuring instrument is set is indicated in the following manner:

With the armatures of the relays in the, third selecting circuit in the positions indicated, a circuit may be traced from ground through the armature of relay 202, contact 221, contact 284 and conductor 000 to the right-hand terminals of lamps 400 and 005 designated 0 units and 5 units. This results in a selection of one lamp in each of two groups of five. In order to complete the selection, a particular one of these two lamps must have battery connected to the left-hand terminal. This is performed in the following manner:

With the armatures of the relaysin the fourth selecting circuit in the positions indicated, a circuit may be traced from positive battery through the armature "of relay 200, contact 23I, contact 298 and the winding of relay 023 to ground close With the armatures of the relays in the fifth selecting circuit arranged as indicated, a circuit may be traced from battery through the armature of relay 200, contact 230, contact 2I8 and contact 330 to the left-hand terminal of lamps 400 to 000. Since battery is connected to the left-hand terminal of only one of the two lamps to the right-hand terminal of which ground is connected, lamp 0 only will light. I I

There now remains the explanation of the manner in which lamp 426 corresponding to the zero tens lamp is selected. This is performed by the fifth selecting circuit also. The path may be traced from battery through the armature of relay 208, contact 239, contact 2I8, contact 429 and the filament of lamp 425 to ground, lighting lamp 026. This is the lamp which indicates 0 in the tens position. The cooperation of the circuits, therefore, has resulted in a selection of lamps corresponding to the setting of the measuring instrument in position 00.00 units.

It will now be assumed that the position of the measuring instrument has been moved to 00.0I units. The permutation code set up on cams IM to I05 is indicated in c0lumn'501 in Fig. 5. For this condition, cams IM and I03 connect ground to conductors I and I82. Conductors I8I, I83 and I80 are open. Relays I'2I and H6 will operate, The operation of relay H5 will in turn operate relays 30I and 302 as heretoiore described. With ground connected to conductor I82, the armatures of relays I27, I23 and I 18 will be actuated to their lower positions. The closing of contact I34 will establish a circuit from negative battery through contact I33, armature of relay IIB, conductor 352 and the windings of relays 304 and 305 in series to positive battery actuating the armatures of these relays to their lower positions. Positive battery will be connected to both ends of the circuits extending through the windings of each of the other relays in the first selecting circuits and their armatures will be in engagement with their upper contacts. Attention is called to the fact that parallel branches extend from conductors 350, 352, 353 and 354 into other selecting circuits but in each instance the path which extends to ground connected to the armature of relay I2I is open. In

through thenr are: closed and. the condition. of the particular selecting circuit is changed in order to effect a new selection.

A. circuit may now be traced from ground through the armature of relay 30I, contact 3I1, armature of relay 303; contact 3E3, armature of relay 304, contact 322, armature of relay 306, contact 325, armature of relay 300, contact 33I and conductor M I to ring 461 Ring 40! connects in: parallel to the inner terminals of lamps I, I4, 26: 30 SI, 64, 16 and. 89. There is. no change in the condition of the other selecting mechani'sm, Battery remains. connected. to the outer terminals. of the lamps in bank 00 to I2. Lamp 0 I therefore, lights;

When the position of the measuring instrumentchanges to 00.02 units, the code set up on the cams is indicated by column 502 in Fig; 5. Cams IOI, I03 and I close their respective contacts I52, I56 and H30 operating the armatures cfijrelays IZ'I, H6, I21, I23, H8, I25 and I20 to -.;tlieir lower positions Negative battery is connected to the armatures of relays H6, H8. and

Relays 30I, 302, 304 and 3 05 will be operfated-asheretofore explained'. The closing of hontactI-38 will establish a circuit from negative atterythrough contact I38, armatureof relay 020 and the windings of relays 300, 3I0, 31 I, 3I2,

3I-3 and 3M inseries to positive battery operating the armatures of these relays to their lower contacts. Other relay armatures will engage their upper contacts. Under these circumstances, acircuit may be traced from ground throughfthe armature of relay 30I, contact 3I1, armature, of relay 303, contact 3I9, armature of relay 1304; contact 322, armature of relay 306, contact325,,armature of relay 309, contact 332 and conductor 412 to ring 482'. This will efiect a selection of lamp 02 in bank 450, the other. selecting apparatus remaining unchanged.

When the measuring instrumentis moved into position 00.03 units, the code set up on cams IN to I05 will be as indicated in vertical column. 503 in Fig. 5. Cams l0'I, I03, I04 and I05 will close their respective contacts I52, I56, I58 and I60. The armatures of relays I2I, II5, I21, I23, H0, I28 I24, H0, I25 and I20 will engage their lower contacts. Relays 30I, 302 304, 305 and 309 to 3M will remain as heretofore described. The operation of the armature of relay I19 to close contact I30 establishe acircuit from negative battery through contact I30 and the windings of relays 306, 301 and 308 inv series to positive battery operating the armatures of these relays to their lower. positions. The armatures of the other relays will engage their upper contacts. For this condition, a circuit may be traced from ground through the armature of relay 30f, contact 3I1, armature of relay 303, contact 310, armature of relay 304, contact 322, armature of relay 308, contact 326, armature of relay 3I0 and contact 334' to conductor 4I3 which connects to ring 463. Ring 463 is connected in parallel to the inner terminals of lamp 03 and a correspond ing lamp in. each of the other seven groups. However, since the condition of the other selecting apparatus remains unchanged, battery will remain connected to the outer terminal of the lamps in the first bank only so that lamp 03 alone will light in indicator bank 450.

Changing the measuring instrument to position 00.04 units, as indicated in vertical column 504 in Fig. 5, will operate the armature of relays 303 to 3 I 4 to their upper contacts while the other relays in the first selecting circuit rema i t condition indicated for the .03 selection. Under this condition, a circuit may be traced from ground through the armature of. relay 30I, contact 3J1, armature of relay 303. contact 3I9, armature of relay 304,. contact 322, armature of relay 306', contact 326, armature of relay 3'I0, contact. 333 and conductor M4 to ring 464. Ring 404 is connected to the inner terminal of lamp 04 and to a corresponding terminal in each of the other seven groups of lamps. Lamp 04: will 'ght, the otherswill remain unlighted.

When. the position of the measuring instrument is changed to indicate. 00.05 units, the armatures of relays 30I to 308 will all be actuated to their lower positions. The armatures of relays 309 to 314 will be. in their upper positions. For this condition, a circuit may be traced from ground through the armature. of relay 30I, contact 3I1, armature of relay 303; contact 320, armature of relay 305,. contact 324', armature. of relay 308, contact 330, armature. of relay 31.4, contact MI and conductor 415. to ring 465.. Ring 465 connests in parallel to the inner terminal of lamp 05 and to: the inner terminal of a corresponding lamp in each of the. other seven groups of lamps in lamp bank450- Lamp 05 will be lighted since the other selecting apparatus remains unchanged. The other lamps will remain unlighted.

The permutation code set up on the cams when the measuring instrumentv is moved into the position for 00.06 units is indicated in vertical col.- umn 506. For this condition, the armatures of relays 30I to 3I4. are all actuated, to their lower positions. Under thisv condition, a circuit may be traced from ground through the armature of relay 30I, contact 311, armature of relay 3.03, contact 320, armature of relay 305, contact 324, armature of relay 308, contact, 330, armature of relay 3I4, contact 342 and a conductor M6 to ring 466. Ring 466 connects .to lamp 06 and to a corresponding lamp in lamp groups 25 to 31, 50 to 62 and 15 to, 81 only. There is no corresponding lamp in lamp banks I3 to 24, 38 to 49, 63 to 1-4, and. 08 to 99. Since battery remains connected to the outer terminal of lamps 00 to I2, lamp 08 only of lamp bank 450 will light.

When the measuring instrument is moved into the position for 00.07 units, a indicated in vertical column 507 in Fig. 5, negative battery will be connected to conductors 343, 350 and 352 operating the armatures of relays 30I to 305 to their lower positions. For this condition, a circuit may be traced from ground through the armature of relay 30I, contact 3", armature of relay 303, contact 320, armature of relay 305, contact 324, armature of relay 308, contact 329, armature of relay 3I3, contact 339 and conductor M1 to ring 1461. Ring 461 connects to the inner terminals of lamp 01 and a corresponding lamp in each of the other seven groups of lamp in lamp bank 450. Lamp 01 only lights as battery is connected to the outer terminals of group 00 to I2 only.

When the measuring instrument moves to the position for 00.08 units, negative battery is connected to conductors 348, 350, 352 and 354. The armatures of relays 30I to 305 and 309 to 3I4 will be operated to their lower position. A circuit may then be traced from ground through the armature of relay 30I, contact 3I1, armature of relay 303, contact 320, armature of relay 305, contact 324, armature of relay 308, contact 320, armature of relay 3 I3, contact 340 and conductor M8 to ring 468. Rin 468 connects to the inner terminal of lamp 08 in group 00 to I2 and to the inner terminal of a corresponding lamp in each of the other seven groups. Lamp 08 lights, the others remain unlighted.

When the measuring instrument is moved into position for 00.09 units, negative battery is connected to conductors 348, 350 and 354. Conductors 352 and 353 are connected to positive battery. Under this condition the armatures of relays 30I, 302, 303 and 309 to 3M are operated to their lower positions. A circuit may then be traced from ground, through the armature of relay 30I, contact 3I1, armature of relay 303, contact 320, armature of relay 305, contact 323, armature of relay 301, contact 321," armature of relay3I I, contact 336 and conductor M9 to ring 469. Ring 469 is connected to the inner terminal of lamp 09 in group to I2 and to the inner terminal of a corresponding lamp in each of the other seven lamp groups. Lamp 09 will light'and the other lamps will remain unlighted.

When the measuring instrument is moved into the position for 00.10 units, negative battery is connected to conductors 348, 353, 3-53 and 354. The armatures of relays 3!, 302, 303 and 306 to 3I4 will be operated to their lower positions. Under this condition, a circuit may be traced from ground through the armature of relay 30I, contact 3I'I, armature of relay 303, contact 320, armature of relay 305, contact 323, armature of relay 301, contact 328, armature of relay 3I2, contact 338 and conductor 420 to ring 410. Ring 4.10 connects to the inner terminal of lamp I0 in lamp group 00 to I2 and to an inner terminal of a corresponding lamp in each of the other seven lamp groups. Lamp I0 will light and the other lamps will remain unlighted.

When the measuring instrument is moved into the position for 00.11 units, negative battery is connected to conductors 348, 350 and 353. Conductors 352 and 354 are connected to positive battery. Under this condition, the armatures of relays 30I, 362, 303, 305, 301 and 303 are operated to their lower positions. A circuit may then be traced from ground through the armature of relay 30I, contact 3I1, armature of relay 303, contact 329, armature of relay 305, contact 323, armature of relay 301, contact 328, armature of relay 3I2, contact 331 and conductor 42I which connects to ring 41L Ring 41! is connected to the inner terminal of lamp II in lamp group 00 to E2 and to the inner terminal of a corresponding lamp in each of the other seven lamp groups. Lamp II only lights.

When the measuring instrument is moved into the position for 0012 units, negative battery is connected to conductors 348 and 350, and positive battery is connected to conductor 352, 353 and 354. The armatures of relays 30I, 302 and 303 will operate to their lower positions. A circuit may then be traced from ground through the armature of relay 30L contact 3H, armature of relay 303, contact 320, armature of relay 395, contact 323, armature of relay 301, contact 321, armature of relay 3i I, contact 335 and conductor 422 which connects to ring 412. Ring 412 connects to the inner terminal of lamp I2 in lamp group 09 to I2 and to the inner terminal of a corresponding lamp in each of the other seven groups of lamps. Lamp I2 only lights.

Operation of second selecting circuit When the measuring instrument moves into the position for 00.13 units, cams IM to I06 will each actuate its corresponding follower to close its left-hand contact. Under this condition, conill) ductors I to I84 respectively, are extended,

' III will have each rotated into the next code position. The movement of the cams'of the middle row sets up a cam and contact pattern in accordance with vertical row 601 in Fig. 6.. Contacts I62 and I64 are closed. Contacts I65, I66, I61 and I68 and I69 are all open. The opening of contact I69 disconnects the ground supply to the top row of cams; A circuit may be traced from ground I29-through contact I6I and conductor I to parallel branches. One branch extends through contact I64, I55, conductor I82and the windings of relays I21, I23 and I18 in series to battery. Another branch extends through con tacts I62, I53, conductor I8I and the windings of relays I26, I22 and H1 in series to battery. JIhe armatures of these relays will be actuated to their lower positions. The armatures of all other relays in Fig. 1 will be operated to their upper positions due to the efiect of current in their biasing windings.

It is pointed out that relays II1 to I20 transmit polar signals to control the armature of the polar relays in the second, third, fourth and fifth selecting circuits. The polar signals are impressed on the left-hand windings of relays in these circuits simultaneously. A single return path to ground connected to the armature of relay I2I is provided for each selecting circuit. The return path for the different selecting circuits extends through the armature of relays I2I to I25. This path is open due to the positions I of the relay armatures except when the particular selecting circuit is intended to respond. After selecting paths are established through the second, third, fourth and fifth selecting circuits, they are locked locally through the armature and contact of each relay in the chain in each selecting path. The selecting paths through each of selecting circuits 2 to 5 are maintained, once they are established, by their respective local locking circuits until the path to ground on the armature of relay I2! is provided at the proper time. Then the relays in the selecting circuits for which ground has been provided respond to the polar signals of the changed code to set up new selections. v s

When the armature of relay II 1'operates to engage contact I32, a circuit may be traced from negative battery through the armature of relay II1 to parallel branches; The only effective branch for. this condition extends through the left-hand winding of relay 20!, conductor 355,

contact I41, armature of relay I22 and contact I40, which is now closed, through the armature of relay I2I to ground. The armature of relay 20I is operated to its lower position to engage contact 226.

The operation of the armature of relay H8 to engage contact I34 establishes a circuit which may be traced from negative battery through contact I34, armature of relay I 53 and conductor 352 to parallel branches. The only effective branch for this condition extends through the left-hand winding of relay 203 over a circuit which has been traced through conductor 355 to ground connected to the armature of relay I2I. The armature of relay 203 is operated to its lower position closing contact 230.

The armature of relay H9 engages contact I31. A circuit may be traced from positive battery through contact I31, armature of relay H and conductor 353 to parallel branches. The branch through the second selecting circuit which is the only effective branch for this condition extends in series through the left-hand windings of relays 206 and 201 to the common ground by way' of conductor 355. Positive battery operates the armatures of relays 206 and 207 to their upper positions.

The armature of relay I20 engages its upper contact. A circuit may be traced from positive battery through contact I39 and the armature of relay I20 to parallel branches. The only effective branch extends through the winding of relays 2I2 to H5 in series and through conductor 355 to the common ground connected to the armature of relay I2 I. Positive battery operates the armatures of relays 2 I2 to 2I5 to their respective upper contacts.

' Attention is called to the fact that whereas negative battery has heretofore been connected at all times to conductor 34B maintaining the armatures of. relays 3M and 302 in their lower positions to supply ground through the various other relays in the first selecting circuit, the armatures of relays 30l and 302 are now operated to their upper positions. Under this con dition a circuit may be traced from ground through the armature of relay 30L contact (H8 and conductor M0 to ring 460. Ring 460 as has been explained connects to the inner terminal of the lowest numbered lamp in each of the eight lamp groups in lamp bank 450.

Whenever conductors I80 to I84 are cut through to any of the higher valued came a selection of the lowest numbered lamp in'each of the eight lamp groups of lam bank 050 is of fected by the operation of the armature of relay 301 to engage contact 3l8 so that ground is connected to conductor M0 and to ring 460 directly without passing through the armatures and contacts of any other relays in the first selecting circuit. From this it should be apparent that whether or not the settings of the relays other than relay 30| are changed at such times, the changes do not establish any selections and they are ineffective as the selection is efiected in each case solely by the operation of the armature of relay 30I to its upper position. It is emphasized, and reference to the top horizontal lines in Figs. 6 and '7 shows, that except in the selection for 00.00 the armature of relay 3% is always actue ated to its upper position when the transmitting channels are connected to the middle and top row of cams. The lowest numbered lamp in each of the eight groups is selected by the first selecting circuit when the middle row of cams is in control and the 00 lamp is always selected by the first selecting circuit in cooperation with the second selecting circuit when the top row of cams is in control. The reason for this will be!- come more apparent from the description hereinafter.

Formerly battery was supplied through the armature of relay 20I to lamp group 00 to I2 to light lamp 00. The selection made by the second selecting circuit has now for the first time been changed. The new selection may be traced from battery through the armature of relay 20l, contact 220, armature of relay 203, contact 230, armature of relay 20?, contact 231, armature of relay 2M, contact 2!, contact 26.9 and conduc- 16 tor 40! to the outer terminals of lamp group I3 to 24.

Attention is called to the fact that every time a selection is made in the second, third, fourth or fifth selecting circuits, the armature of each relay in the selecting chain is locked in position to maintain the selection.

Certain of the locking paths will be traced by way of example. In the case of the selecting path which supplied battery to the outer terminal of lamps 00 to I2 in lamp bank 450, the circuit extended through the armature of relay 20I and contact 225 only in the second selecting circuit.

The armature of relay 20| was locked in this position by the circuit extending from positive battery through contact 225 and the middle wind ing of relay 201 to ground. For the second selection of lamp groups I3 to 24 in lamp bank '150, the circuits for locking the armatures of relays HM and 203 in their lower positions and the ar matures of relays 201 and 2M in their upper positions extends from battery connected to the armature of relay 20! along the chain, through the armature and contact of each relay involved in the selection through a locking winding on each relay to ground.

The selecting path for the I3 to 24 group of lamps in lamp bank 450 may be traced from bat tery through the armature of relay 2!, contact 226, armature of relay 203, contact 230, armature of relay 201, contact 231, armature of relay 2, contact 25L contact 269 and conductor 40I to lamp group IE to 20. Lamp I3 is lighted since the first selecting circuit, as has been shown, simultaneously selects the first lamp in each p.

Lamp 420 corresponding to 0 in the tens group and lamp 440 corresponding to 0 in the units group remain unaffected as the third, fourth and fifth selecting circuits have not been altered. The lighted lamps correspond to a setting of 00.13 units.

When the position of the measuring instrument is changed to the 00.14 setting cams I 0| to I 00 are rotated into their next succeeding position. In this position conductors I to I84 are no longer cut through to the higher valued cams and cams I01 to H0 no longer control the settings of the relays in the second selecting circuit. This explains why the relays in the second selecting circuit have been looked as their settings must be maintained during the interval while the measuring instrument is in the region between .13 and .24 units.

Attention is called to the fact that the relays in the first selecting circuit are not locked. During the interval while conductors I80 to I84 were cut through to the higher valued cams, the first selecting circuit is arranged so that it selects the inner terminal of the lowest numbered lamp in each group. Therefore, while conductors I80 to I84 are cut through to the next higher valued cams, two selections are being made rather than one and this is accomplished by effecting a selection by the first selecting circuit by means of one signal element alone. The various codes assigned have been arranged so that, whenever conductors I80 to I84 are cut through to the higher valued cams, except for the condition for 00.00 units, relay SM is always released.

It will be assumed that th position of the measuring instrument continues to change as the measured quantity is increased. As the quantity is increased in the range from 00.13 units to 00.24 units each of the one-hundredth unit codes used operate their respective relays in Fig. 1.

for the setting from .01 unit to .12 unit will be repeated except the cod for .06 unit. This may be seen from a comparison of vertical columns 501 to 512 in Fig. 5 with vertical columns 514 to 524. Eachof these transmitted codes results in the connection of ground to the inner terminal of a difierent one of lamps I3 to 24, inclusive, in lamp bank 450.

When the measuring instrument is in the position for 00.25 units, conductors I80 to I84 will again be cut through to the middle group of cams.

Reference to column 602 in Fig. 6 indicates that for this condition, cams I 01, I08 and close contacts I62, I64 and I68, respectively. Contact I66 associated with cam I09 is open. The armatures of relays I I1, H8 and I20 are operated to engage their lower contacts. The armature of relay I I9 is operated to engage its upper contact.

.Negative battery is connected to conductors 350,

352 and 354. Positive battery is connected to conductor 353. It is pointed out that the efiect of positiv or negative current in the left-hand or operating windings of the. relays in selecting circuits 2 to is dominant over the effect of the holding current in these relays. The armatures of relays I, 203 and 2I2 to 2I5 are operated to their lower positions. The armatures of .relays 206 and 201 are operated to their upper positions.

The selecting circuit for lamp group to 31 in lamp bank 450 may now be traced from batterythrough the armature of relay 20I, contact 226, armature of relay 203, contact 230, armature of relay 201, contact 231, armature of relay 2I4, contact 252, contact 264 and conductor 402 to the outer terminals of lamps 25 to 31.

As the measured quantity continues to increase cams I8I, I06 will continue to rotate. When the measuring instrument is in a setting corresponding-to 00.26 units, conductor I80 to I84 will be disconnected from their respective cams in the middle row. While the second selecting circuit remains in the condition of supplying battery over conductor 402 to the outer terminal of lamps 25 to 31 of lamp bank 450, cams IN to I65 will resume control. Permutation code signals will be transmitted to effect the selection of lamps 26 to 31 in lamp bank 450 in the same manner as described for the corresponding lamps in lamp group 00 to I2. Then once more raised surfaces on the peripheries of cams IOI to I06, will make the middle row of cams efiective for the next selection. Reference to vertical column 603 in Fig. 6 shows that for this condition cams I01 to' H0 close their respective right-hand contacts and tive battery is therefore connected to conductors 350, 352, 353 and 354. The armatures of relays 20I, 203, 206, 201 and 2I2 to 2I5 will be actuated to engage their lower contacts. The selecting circuit extends from battery through the armature of relay 201, contact 226, armature of relay 203, contact 230, armature of relay 201, contact 238, armature of relay 2I5, contact 254, contact 262 and conductor 403 to the outer terminals of lamps 38 to 49. The armature of relay I is simultaneously operated to its upper position to engage contact 3I8 which will again effect the selection of ring 460 in a manner heretofore described so that lamp 38 of lamp group 38 to 49 will be lighted.

When the position of the measuring instrument is moved to 00.39 units, cams IOI to I05 again resume control. The inner terminals of lamps 39 to 49 will be selected in a manner corresponding :to that heretofore described while battery remains Nega- 7 18 connected from the second selecting circuit to lamp group 38 to 49 in lamp bank 450.

When the position of the measuring instrument has been changed to correspond to a setting of 00.50 degrees, the relay settings of the second selecting circuit will be changed to correspond to the code indicated in vertical column 604 of Fig. 6.

Reference to vertical column 604 in Fig. 6 indicates that cams I01, I08 and I09 close their right-hand contact operating the armature of the corresponding. relays to engage their lower contacts. The selections'by the second selecting circuit involve the operation of the armatures of relays 20I, 203, 206 and 201 to their lower positions and the operation of the armature of relays 212 to 2I5 to their upper positions. Under this condition, a circuit may be traced from battery throughthe armature of relay 20I, contact 226, armature of relay 203, contact 230, armature of relay 201, contact 238, armature of relay 2 I 5, contact 253, contact 212 and conductor 404 which connects to the outer terminals of lamps 50 to 62. Lamps in the 50 to 62 group will therefore be lighted as the measuring instrument operates in this zone.

When the measuring instrument moves to a position corresponding to 00.63 units, reference to vertical column 605 in Fig. 6 discloses that cams I01 and I09 close their right-hand contacts actuating the armature of the corresponding relays in Fig. 1 to engage their lower contacts.

The armatures of relays 20I, 206 and 201 in the second selecting circuit will be actuated to engage their respective lower contacts. The armatures of all other relays will engage their upper contacts.

For this condition, a. circuit may be traced from positive battery through the armature of relay 20I, contact 226, armature of relay 203, contact 229, armature of relay 206, contact 236, armature of relay 2I3, contact 249, contact 211 and conductor 405 to the outer terminals of the lamps 63 to 14. This selection will be maintained while the measuring'instrument measures quantities in the range 00.63 to 00.74 units. Meanwhile ground will be connected from the first selecting circuit to the inner terminals of the lamps in lamp group 63 to 14 in the manner described.

Reference to vertical column 606 in Fig. 6, indicates that for thi condition, cams I01, I09 and H0 will close their associated right-hand contacts operating the armatures of the corresponding relays in Fig. 1 to their lower positions. The armatures of relays 20I, 206,201, 2I2, 2I3, 2M and 2I5 will be actuated in turn to their lower positions, while the armature of relay 203 is actuated to its upper position. For this condition, a circuit may be traced from positive battery through the armature of relay 20I, contact 226, armature of relay 203, contact 229, armature of relay 206, contact 236, armature of relay 2I3, contactl250, contact 214 and conductor 406 to the outer terminals of lamps 15 to 81. During the interval While the measuring instrument is changing through the region 00.75 units to 00.87 units, ground will be connected by the first selecting circuit to the inner terminals of these lamps to light lamps corresponding to the setting of the instrument.

When the measuring instrument is moved to position 00.88 units, reference to vertical column 607 in Fig. 6 indicates that cams I01 and H0 close their respective right-hand contacts operating the armatures of the corresponding relays in Fig. 1

to their lower positions. The armatures of relays moves into the 01.00 unit zone.

20!, and 2I2to .2I5will be actuated in turn to their lower positions. The armatures of :relays 203, 206 and 20'! will be actuated to theirupper positions. Under this condition, a circuit may be traced from positive battery through the armatureof relay 20!, contact 225, armature of relay .203, contact 229,. armature of relay 200, contact 235, armature of relay 2I2, contact 248, contact 219 and conductor 401 to. the outer terminals of lamps 28 to 99 inlampbank 450. While this selection is maintainedv by the locking circuit, ground will be connected to the inner terminals of lamps 88 to 99 to light lamps corresponding to the instrument setting.

Up to the present it hast been assumed that the measuring. instrument has been changing through the region from 00.00 units to 00.99 units. The settings of the armatur'es in the third, fourth and fifth selecting circuitshave been maintained unchanged during this interval. Lamps 426 and 440 have been lighted during this interval to complete the indication. The position of the measuring instrument is now to be changed so that it It is necessary, therefore, to extinguish lamp 4'40 and light lamp MI to indicate this change. i The manner in which this is effected will now be explained.

operation of third, fourth and fifth selecting Each time that the measuring instrument is in position such that the two right-hand digits of the measured quantity correspond to zero, the position of cams IOI to I06 and I07 to III will be such that conductors I81. to I04 are further extended to the top row of cams to transmit the codes for the higher Valued digits as well as for zero in the two right-hand positions of the number simultaneously. I A, circuitmay be traced from ground I29 .through contact .IIiI and contact I60, to contacts I10;to I13 in parallel. Reference to column 701 of Fig. 7 indicates that for the 01.00 full unit setting, the contacts associated with cam H3 and IIII are closed-and that contacts I'IOand I13 associated with cams II2, and-H5, respectively, are open. The, circuit; therefore, extends through contact Ill, contact I03, contact I55 and the windings of relays 121,123 and H8 to positive battery, operating thearmatures of relays I21, I23 and II8 to their lower positions. A parallel circuit extendsthrough contact I'I-2, contact I65, contact I51 and the windings of relays I28, I24 and II 9 in series to positive battery, operating the armatures of relays I28, I24. and H9 to their lower positions. The armatures of relays I25 and I will be in their upper positions.

Attention is called to the two top horizontal lines in Fig. i -which indicate that except for the 00.00 unit selection, both cams H2 and I0! maintain their associated contacts open at all times while the toprow of cams is functioning to transmit codes defining the higher valued digits. Relays IIS and Ill therefore will always transmit positive battery to the first and second selecting circuits at such times so that the armatures of relays 30I and 302 in the first selecting circuit and of relay 20I in the second selecting circuit will engage their upper contacts, at such times and will always make a selection of the 00.00 lamp in lamp bank 450. In other words, except in the case of the 00.00 unit selection, the armatures of relays 30I and 302 are always operated to their upper positions whenever the transmission conductors connecting the stations are cut through transmission of codes for full units.

to the middle row of cams. And whenever the transmission. conductors I80 to I84 are cut through to the top row of cams, not only is the armature of relay in its upper'positionso'as to supply ground to the inner terminal of the first lamp in each one of the eight lamp groups in lampba'nk 4.50, but the armature of relay 20I is also on each such occasion operated to engage its upper contact 225 so as to connect battery to the outer terminals of lamps00 to 12. As a result of this, the .00 lamp in lamp bank 450 is always selected whenever transmission conductors I80 to I are cut through the two lower valued groups of cams to the top row of cams which control the From this it should be apparent that. now three selections are made when a full unit selection is made.

Before proceeding to describe the manner in which lamp MI corresponding to full unit I is selected, the manner in which the relays which are locked in position for each selection in the second selecting.v circuit are unlocked will first be explained. It was heretofore explained that as the armatures of the various relays in the second selecting circuit involved in making any particular. selection were operated to one or the other of their respective contacts, they were locked in that position, while the measuring instrument remained in the corresponding zone. Each of the relays in the second selecting circuit responds to polar signals transmitted from relays II'I to I20. The path in each instance extends from positive or negative battery connected to the armatures of relays H! to I20 through the left-hand windings of the relays in the second selecting circuit, through common conductor 355 to .ground connected to the armature of relay I2I. The efiect of current flowing in thi path, whether it be from positive or negative battery, preponderates over the effect of the locking current so that the relays respond to the polar signals for each new selection.

When the transmitting conductors are connected through to the top row or full unit earns, the armatures of relays I22. and II! are always actuated so as to engage their respective upper contacts due to the effect of current in their biasing windings. Under this condition, a circuit may be traced from positive battery, through contact I 33, armature of relay I ll, conductor 350, lefthand winding of relay 20I, and conductor 355. Since the armature of relay I22 no longer engages contact MI, an alternative path has been established through contact I40, armature of relay I26, and contact I 43, the armature of relay I23 being operated to its lower position, through the armature of relay I23, contact I42, armature of relay I22, contact I40 and the armature of relay I2I to ground. Reference to the middle horizontal line in Fig. 7 discloses that except for the 0, 5, l0, 15, 20 and 25 unit settings of the measuring instrument, cam II3 is in condition so that contact Il'I is always closed for each of the full unit selections. Contacts I63 and I are also always closed so that the armatur'es of relays I21, I23 and IE8 are always in their lower positions for every full unit selection except in the selections of full units which are multiples of five. As a result of this, the armature of relay 20I will always be actuated to engage and lock with its upper contact 225 for everyone of the full unit selections which is not a multiple of five over the path which has been traced to ground connected to the armature of relay I2I through contact I48. For the full unit selections which are multiples nected to the armature of relay I2I.

actuated to engage its upper contact in a manner to be understood from the following, so that when the measuring instrument is moved into any full unit position, the armature of relay I will always be actuated to engage its contact 225 and make a selection, as has been shown, of the outer terminals of lamps .00 to .12 in lamp bank 450. At the same time, the first selecting circuit cooperates to select lamp .00.

Reference to vertical column 701 in Fig. 7 discloses that in selectin the lamp corresponding to one full unit, cam H3 and H4 close their respective contacts. The armatures of relays H8 .and II 9 are actuated to their lower positions. The armature of relay I20 is actuated to its upper position. In the case of relay I I8, a circuit is established from negative battery through contact I34, armature of relay H8, left-hand winding of relay 202, conductor 356, contact I43, armature of relay I23, contact I42, armature of relay I22, contact I and armature of relay I2I to ground, operating the armature of relay 202 to'its lower position. With the armature of relay I I9 operated to engage its lowe contact, a circuit may be traced from negative battery, through contact I30, armature of relay I I9, conductor 353, left-hand winding of relay 205 to conductor 356 which extends as has been shown to ground con- Since the armature of relay I20 engages its upper contact I39, a circuit may be traced fom positive battery, through contact I39, armature of relay I20, conductor 354 and the left-hand windings of relays 2I0 and 2H in series to conductor 356 which extends to ground connected to the armature of relay I2I. Th'e armatures of relays 2I0 and 2I I are actuated to engage their upper contacts. A circuit may now be traced from ground through the armature of relay 202, contact 228, armature of relay 205, contact 234, armature of relay 2I I, contact 245, contact 282 and conductor 48I to the right-hand terminals of lamps MI and 446 corresponding to full unit indications f I and 6.

The relays in the fourth and fifth selecting circuits have assumed the positions shown as a result of operation in a previous cycle of operation which may be understood from the description hereinafter. A circuit may be traced from battery through the armature of relay 204, contact 23I, contact 298 and the winding of relay 423 in Fig. 4 to ground, so that the contacts associated with relay 423 are all closed at this time. The armatures of relays 423 will remain in the operated positions as the winding of relay 423 is maintained energized while the selecting path through the fourth selecting circuit is maintained by its locking circuit. A circuit may also be traced from battery through the armature of relay 208, contact 239, contact 2I8 and contact 430 to the left-hand terminal of units lamps 440 to 444. Lamp 44I which corresponds to full unit I will light. A circuit may also be traced from positive battery through the armature of relay 208, contact 239, contact 218, contact 429 and the filament of lamp 425 to ground so that the zero tens lamp is lighted. The lighted lamps 423, MI and .00 indicate a setting of the measuring instrument corresponding to 01.00 units.

When the measuring instrument is moved into the position corresponding to the setting for 01.01 units, cams IOI to I05 will resume control and the cycle of operations may be repeated while the measuring instrument moves through the range from 01.01 to 01.99um'ts. The first and second selecting circuits will cooperate "to select each one ofv the lamps from .0I to .99 in lamp bank 450 a themeasuring instrument sweeps through the positions from 0I.0I to 0I.99 units.

,Thereupon the transmitting conductors will be again out through to the full unit cams. On this occasion, as may be seen from reference to vertical column 702 in Fig. 7, cams H3, H4 and. H5

close contacts I1I, I12 and I13 respectively. The

armatures of relays. I21, I23, H8, I28, I24, H9, I25 and I 20 will all be actuated to their lower positions. The armatures of relays 202 and 205 will again be actuated to their lower positions. The closing of contact I38 establishes a circuit from negative battery through contact I38, armature of relay I20, conductor 354, left-hand windings of relays 2 I0 and 2I I to conductor 356 which extends to ground connected to the armature of relay I2I. The armatures of relays 2I0 and 2H will be operated to their lower postions. A circuit may then be traced from ground through the armature of relay 202, contact 228, armature of relay 205, contact 234, armature of relay 2I I, contact 245, contact 200 and conductor 482 to the right-handrterminals of lamps 442 and 441 corresponding to full units 1 and 2. The condition-of the fourth and fifth. selecting circuits remains unchanged as they cannot respond to the polar signals transmitted by relays H9 and I20 since the path to ground connected to the armature of relay I2I is open in each instance. Battery will, therefore, remain connected tothe lefthand terminal of lamps 440 t 444 corresponding to full units 0 to 4 and lamp 2 will light.

When the transmitting conductors are again out through to the full unit cams, when the measuring instrument is in the position corresponding to 03.00 units, as indicated in column 703 of Fig. 7, the armatures in Fig. 1 controlled by cams H3 and H5 will be in their lower positions. The armatures of other relays in Fig. 1 will be in their upper positions. For this condition, the armature of relays 202, 2I0 and 2H will be operated to their lower positions and the armature of relay 205 will be operated to itsupper position. A circuit may then be traced from ground to the armature of relay 202, contact 228, armature of relay 205, contact 233, armature of relay 2| 0, contact 244, contact 289 and conductor 483 to the right-hand terminals of lamps 433 and 448 corresponding to full units 3 and 8. Battery will be connected to the right-hand terminal of lamp 443 and lamp 443 corresponding to full unit 3 will light.

When the measuring instrument has moved into position corresponding to 04.00 units as indicated in vertical column 104 in Fig. 7, contact I1I associated with cam H3 will close to operate the armatures of relays I21, I23 and H8 to their respective lower positions. The armatures of all other relays in Fig. 1 Will be in their upper position. For this condition, the armature of relay 202 is actuated to its lower position. The armatures of other relays in the third selecting circuit will be actuated to their upper positions. A circuit may be traced from ground through the armature of relay 202, contact 228, armature of relay 205, contact 233, armature of relay 2I0, contact243, contact 29I and conductor 484 to the right-hand terminals of lamps 444 and 449 corresponding to full units 4 and 9. Since battery remains connected to the left-hand terminal of lamp 0 to 4, lamp 4 will light.

For the 05.00 degrees position of the measuring 23 instrument, as indicated in vertical column 705 in Fig. 7, cams H4 and H5 close contacts I12 and [13. The armatures of relays I28, I24, II9,

I25 and I20 will be actuated to'their lower posi- V tion's. The armatures of all other relays in Fig. l will'be in their upper positions.

Attention is particularly called to the fact that in this position of the measuring instrument, as in'each full unit position which is a multiple of five, the armatures' of relays I21, I23 and H8 are in their upper positions. For this condition the armature of relay 202 will be actuated to its upper position. The circuit may be traced from positive battery through contact I35, armature of relay H8, conductor 352, left-hand winding of relay 202, conductor 356, contact I49, armature of relay I21, contact I45, armature of relay I 24, contact I44, armature of relay I23, contact I42, armature of relay I22, contact I40 and the armatureofrelay I2I to ground. A circuit may then be traced from ground through the armature of relay 202, contact 221, contact 284, and conductor 480-to the right-hand terminals of- lamps 440 and 445 corresponding to full units and 5. The operation of the armature of relay I I9 to its lower position establishes a circuit from negative battery through contact I36, armature of relay H9, conductor 353, left-hand winding of relay 204, conductor 351, contact I45, armature of rela I24, contact I44, armature of relay I23, contact I42, armature of relay I22, contact I40 and the armature of relay I2I to ground, operating the armature of relay 204 to its lower position. The closmg of contact I30 establishes a circuit from negative battery through contact i38, armature of relay I20. conductor 354, left-hand winding of relay 209 and conductor 351 which extends to ground connected to the armature of relay 12L The armature of relay 209 is operated to its lower position. A circuit may then be traced from positive battery through the armature of relay 204, contact 232, armature of relay 209, contact 242, contact 292, and the Winding of relay 424 to ground, operating relay 424, A circuit may now be traced frompositive battery through the armature of relay 203, contact 239, contact 218 and contact 490 to the left-hand terminals of lamps 445 to 409 corresponding to full units to 9.

Lamp 445correspondihg-to full unit 5 will, therefore, light, Relay 424 is maintained operated due to the locking of the armatures of relays 204 and 209 in their lower positions Forcodes corresponding to 06.00, 07.00, 08.00 and 09.00 units as may be'seen from reference to vertical columns 105, 101, and 109 in Fig. 7,

' com I I3 closes its contact and consequently the armature of relay 202 is operated to {its lower position in each instance, This breaks the original path to ground over which the armatures of relays 204 and 209 were operated to their lower positions. But since as has been explained relays 204 and 209 are locked over local paths within the fourth selecting circuit itself, the armatures of relays 2'04 and 209 remain locked in their lower positions. This in turn-maintains relay 424 open ated to maintain battery connected to the lefthand terminals of full units lamps 5 to 9 While selections of these lamps are made by the third selecting circuit which connects ground to each one of their right-hand terminals as its proper code is received from relays 1 I8 to I 20.

Comparison of vertical columns 706 to 709 with vertical columns 701 to 704 in Fig. 7 indicates that the codes for settings 6 units to -9 units are the same as for 1. unit to 4. units, respectively.

Each one of the corresponding selections by selecting circuit 3 has been shown to select units lamps I and 6, 2 and 1, 3 and 8, an 4 and 9 in pairs. With battery from the fifth selecting circuit now remaining connected to the left-hand terminals of units lamps 5 to 9 in parallel, units lamps 6 to 9 will be selected in response to the codes shown in vertical columns 706 to 709 in Fig. 7.

The code for the setting of the measuring instrument at ten full units is shown in vertical column 1 I 0,

Once again for reasons explained the armatures of relays H6 to H8 are all in their upper positions. The fourth selecting circuit is free to res'pond. Cam I I4 alone closes its contact. The armature of relay 204 in the fourth selecting circuit is again operated to its lower position. The armatures of other relays in the fourth selecting circuit remain in their upper positions.

A circuit may now be traced from battery through the armature of relay 204, contact 232, armature of relay 209, contact 24I, contact 294, and the winding of relay 425 to ground, closing the contacts of relay 425.

The fifth selecting circuit remains unchanged. A circuit may therefore be traced from battery through the armature of relay 208, contact 239 and contact 2 I8 to parallel branches. One branch extends through contact 436 and the filament of lamp 421' to ground lighting lamp 421, which is the lamp corresponding to settings in the range from 10.00 units to 19.99 units. The other parallel branch extends through contact 431 to the left-hand terminal of lamps 440 to 444 which are full units lamps 0 to 4. Simultaneously th righthand terminals of lamp 0 will be selectedby the third selecting circuit while the first and second cooperate to select the .00 lamp in lamp bank 450.

When the position of the measuring instrument advances the fourth and fifth selecting circuit remain locked to maintain the selection of lamp 421 until, as indicated from reference to vertical column 715 in Fig. 7, the instrument setting reaches the 15.00 unit position.

During this interval the first, second and third selectingcircuits respond to the permutation code signals from the cams in a manner which should be understood from the foregoing to control their respective full units lamps and the lamps in lamp bank 450.

When the setting of the measuring instrument reaches 15.00 units, reference to vertical column N5 of Fig, 7 and the foregoing description indicates that cam H5 alone closes its contact. Consequently, the armature of relay 208 will be actuated to its lower position over a circuit from negative battery through contact I38, armature of relay I20, left-hand winding of relay 208, contact I41, armature of rela I25, contact I46, armature of relay I24, contact I44, armature of relay I23, contact I42, armature of relay I22, contact I40 and armature of relay I2I to ground. Positive battery connected to the armatures of each of relays I I6, H1, H8 and H9 will operate the armatures of relays 30I, '20I, 202 and 204 to engage their upper contacts.

The cooperation of the first and second selecting circuits will result in the usual selection of the .00 lamp in lamp bank 450. The third selecting circuit will connect battery to the right-hand terminal of full units lamps 0 and 5. The fourth selecting circuit will 'reoperate relay 423. Under this condition a circuit may be traced from battery through the-armature of relay' 208, contact 240 and contact 2I0 to parallel circuits; One branch extends throughcontact 43I and through the filament of lamp 421 to ground to maintain the middle tens lamp lighted. The second branch extends through contact 432 to the left-hand terminal-of lamps 445 to 449 corresponding to full units 5 to 9. Lamp 445 or unit lamp 5 will light. The lighting of this combination of lamps provides the 15.00 unit indication.

Reference to Fig. 7 discloses that the codes for each of the four different full unit settings between multiples of five are the same. For instance, the codes for l, 2, 3 and 4 units are the same as for 6, 7, 8 and 9 units, etc. The third se-- lecting circuit functions in the same manner for each group of four. For each code received by the third selecting circuit ground is connected to the right-hand terminal of a different lamp in each of the two groups of units lamps.

For the 20.00 unit setting, reference to'vertical column 720 indicates that cam H4 and H5 close their contacts. The annatures of relays I I9 and I20 will be actuated to their lower positions. When the armature of relay H9 engages with its bottom contact a circuit is established from negative battery through contact I 30, armature of relay H9, conductor 353, left-hand winding of.

relay 204, conductor 351, contact I45 and through the armatures and upper contacts of each of the other relays in the chain circuit which extends to ground connected to the armature of relay I21. The armature of relay 204 will be actuated to 4 close its contact 232. When the armature of relay I20 engages with its contact I38 a circuit i closed which extends from negative battery through contact I38, armature of relay I20, left-hand winding of relay 209 to conductor 35'! which also extends to ground connected to the armature of relay l2I. The armature of relay 209 will be actuated to connect with its lower contact 242. The armatures of relays H5, H1 and H will all be actuated to engage with their upper contacts. As a result of this the armatures of relay 30!, 20I and 202 will all engage their upper contacts. Under this condition the first and second selecting circuits will cooperate as heretofore described to select the .00 lamp in the hundredths lamp bank 450. When the armature of relay 202 engages with contact 221 the third selecting circuit will connect ground to the right-hand ter-' minals of units lamps 440 and 445 corresponding to units 0 and 5. With the armatures of relays" 204 and 209 actuated to engage their respective lower contacts a circuit may be traced from loattery through the armature ofrelay 204, contact 232, armature of relay 209, contact 242, contact 292 and the winding of relay 424 to ground closing the contacts of relay 424.

The armature of rela 08 in the fifth selecting circuit was actuated to its lower position to close contact 240 when the measuring instrument was in the position corresponding to I units. The

armature of relay 208 remains locked in this polamps indicates that the measuring instrument is setin the 20.00 position. I 1

For the 25.00 position of the measuring instrument reference to verticalcolumn 725 of Fig. .7 indicates that cam I I4 only closes its contact. As a result of this the armature of relay H9 is ac; tuated to its lower position closing contact I36. The armatures of relays II6, I H, H8 and I are all operated to their upper positions. Th 00-- operation of the first and second selecting circuits again efiects the selection of .00 lamp in the hundredths lamp bank. The third selecting circuit connects ground to the right-hand terminals of units lamps 440 and 445m the sam manner as heretofore described. The armature of relay 204 in the fourth selecting circuit will be actuated to'itslower position to close contact 232; The armature of relay 209 in the fourth @selectingc'ircuit will be actuated to its upper position to close, contact 24I. A circuit may be traced which-extends from battery through thearmature ofrelay 204, contact 232, armature of relay 209, contact 24L contact 294 and the winding ofrelay 425 to ground closing the-contacts of relay 425. The armature of relay 208 in the fifth selecting circuit remains locked in engagement with contact 240. A circuit may be traced'from batter through the armature of rela '2'08, contact 240 and contact 2I6 to parallel branches. one parallel branch extends through contact 49I whichconnect 'to the left-hand terminals of units lamps 445m 440 in parallel. Units lamp 445 corresponding to 5 units will therefore light. The second parallel branch extends through contact 438 and th fila ment of lamp 428 to ground lighting lamp-428. Lamp 428 as explained is the-20 tens lamp. The lighting of thiscombination-of lamps-indicates that the measuring instrument is in'the 25.00 position.

It is pointed out that in the description above of the'operation for the-00.00 position" it was stated that the armatures of the relays were in the positions indicated, but the mannerin-which the armatures oftherela'ys in the second, third, fourth and fifth selecting circuits were operated to these positions was not explained. This will now be made clear. 1:

Reference to vertical columns 500, 600 and 700' in Figs. 5. 6 and '7 shows that for this condition, cams I00, III and II2 close contacts IBI; I60 and H0. The armatures of relays I2I'an'd H6" will beoperated to their lower positions. The armatures of all other relays .in Fig. 1 will be 01') erated to their upper positions. .'Positive.- battery is therefore impressed through 1 theleft-hand windings of each of the relays in the second, third, fourth and fifth selecting circuits. Since the armature of relay I2I is down the usual return path to ground for the operation of the relays in the second, third, fourth and fifth selecting circuits is open. For this condition an alternate path extends from conductors 355, 353 and 35'! through contact I48, I49 and I50 respectively. A chain circuit is established through these contacts which connects each of these conductors to conductors 341. The left-hand Winding of relay 208 also connects to conductor 347. Conductor 347 extends through contact 32I, ar-

mature of relay 304, contact 3I9, armature of re- I lay 303, contact 3I'I and the armature of relay 30| to ground. The, armatures of all of the relays in the second, third, fourth and fifth selecting circuits are therefore operated to their upper positions. A a result of this relay 423 is operated. The cycle may then be repeated.

Relays 22!, 222, 223 and 224 are maintained in the positions shown at all times in the present invention. It was pointed out that the present invention is arranged to measure increasing quantities. A rotational control circuit 593, which is not part of this invention, is indicated by a rectangle. By means of the rotational control circuit which connects to all five selecting circuits and control relay Hi to 224 the circuit herein may be modified to measure both increasing and decreasing quantities. However, this feature is not part of the present invention and no claims are directed to it hereunder.

What is claimed is:

1. A plurality of selecting devices connected in parallel to a single transmitter, means for transmitting a single permutation code signal combination from said transmitter to said devices simultaneously, means for effecting ultimate selectionsby said device in response to the cooperative action of a plurality of signal elements of said combination and means for simultaneously efiecting ultimate selections by said devices in response to single signal elements of said combination 2. A single permutation code signal transmitter connected to a plurality of selecting devices arranged in parallel, means for transmitting permutation code signal combinations from said transmitter to said devices simultaneously, means in said devices for identifying each of the digits of any number from 0 to 100, inclusive, means in said devices for effecting selection by said devices in response to the cooperation of at least three signal elements of a multi-element permutation code signal combination at a first time and means for controlling said devices individually in response to the condition of individual signal elements of a permutation codesignal combination at a second time.

3. A single permutation code signal transmitter, mean connected to said transmitter for transmitting permutation code signal combinations to four separate independent selecting devices connected in parallel to said transmitter, means for effecting selections by one of said devices in response to the cooperative action of a group of elements of a single permutation code signal combination at a first time, and means for simultaneously controlling a group of said devices individually to effect a separate independent ultimate selection by each one of said group of devices in response to the condition of separate individual elements only of said permutation code signal combination at said first time.

4. In a permutation code signaling system, a first, second and third transmission channel, means for impressing either of two electrical conditions on each of said channels to form Formutation code signals, a first selecting device comprising a switch selectively operable to either of two positions connected to said first channel only, a second selecting device independent of said first device comprising two switches each selectively operable to either of two positions connected individually to said first and said second channel, a third selecting device independent of each of said other devices comprising three switches each selectively operable to either of two positions connected individually to said first, second and third-channels, and means for efiecting three separate independent ultimate selections simultaneously through paths through said switches in each device in response to a single multielement permutation code signal combina tion impressed on said channels.

5. In a permutation code signal data transmission system for transmitting code signals corresponding to numbers defining measurements by a data measuring instrument, a first, second and third set of cams, means responsive to the operation of said instrument for operating said cams, a first, second and third set of contacts, mean responsive to the operation of said respective sets of cams, for arranging each of said respective sets of contacts so that each set forms permutation codes defining a separate portion of a mulitdigit number corresponding to a measurement made by said instrument, a plurality of separate signal transmission channels, means for connecting said channels to said first set of cams so as to transmit permutation code signals defining a first portion of said number at a first time, means for connecting said channels to said second set of cams so a to transmit permutation code signals defining a second portion of said number at a second time, means for connecting said channels to said third set of camsso as to transmit permutation code signals defining a third portion of said number at a third time and means for defining a first portion of a number and a second portion of a number by means of a portion of a permutation code and defining the third portion of a number by the remaining portions of a code when said channels are connected to said third set of cam to define the corresponding complete setting of said measuring instrument at a fourth time.

EDWARD M. SMITH.

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