US 3841443 A
An elevator system which includes an elevator car mounted for movement in a structure to serve landings therein. The car and corridor calls are serially transmitted at a first rate which is at or below a predetermined maximum limit imposed by noise in the data transmission system. A rate converter provides high speed images of the serial car and corridor call signals, providing them at a second rate which is above the predetermined maximum limit and also above a predetermined minimum rate for consideration by the floor selector. The minimum rate is determined by the number of floors in the associated structure and the length of time valid data is presented for a floor when the data is transmitted at the first rate.
Description (OCR text may contain errors)
United States Patent Booker, Jr.
[I 11 3,841,443 Oct; 15, 1974 ELEVATOR SYSTEM Primary ExaminerRobert K. Schaefer  Inventor: Clyde A. Booker, Jr., Pittsburgh, Pa. Ass'smm Exammerw' Duncanson Attorney, Agent, or Firm-D. R. Lackey  Assignee: Westinghouse Electric Corporation,
Pittsburgh, Pa. 57 1 ABSTRACT  Filed; Sept. 13, 1973 An elevator system which includes an elevator car mounted for movement in a structure to serve land-  Appl' 396956 ings therein. The car and corridor calls are serially transmitted at a first rate which is at or below a prede-  [1.8. CI 187/29 R termined maximum limit imposed by noise in the data  Int. Cl B66b 1/18 r n mi i n y em. A r con rter provide high  Field of Search 187/29 speed im g f h ri l r and Corridor Call g providing them at a second rate which is above the  Ref Cit d predetermined maximum limit and also above a preden- STATES PATENTS termined minimum rate for consideration by the floor 3 589 473 6/1971 Kirsch at al 187/29 selector. The minimum rate is determined by the num- 373988O 6/1973 187/29 ber of floors in the associated structure and the length of time valid data is presented for a floor when the data is transmitted at the first rate.
14 Claims, 4 Drawing Figures ,QQ ,los roa j MULTIVIBRATOR lg'gi fg gg (320mm (5 |z MHZ) CLOCK SIGNALS (32OKHZ SHIFTED) ussos- 1 I ussos 14o COMPARATOR ."'"\D 50s- J w 5* K025 Q Ma MULTIVIBRATOR "Qgggiggg 7 C D Q (32 KHZ) SIGNALS ATREGULAR 6 RATES l(P5, 5
i C D (NO OF 44 D Q E SHIFT c EGISTER FROM CALL Q REGISTERS D c 14s To FLOOR BSERIALIZERS 22 D Q OP ATSOOHZ E SHIFT Z SELEgTOR RATE QEGIST'ER 2 320 KHZ I34 0 c RATE (I20 ("4 32 D Q g sun-"r I48 I 6 ncblbll; z
PATENIEDOU I SL974 3 841 443 SHEET 1 OF 3 TIMING I N 46 TIMING- f REMAINING CARS N EL i SYSTEM OF. BANK CONTROL PROCESSOR 2o TIMING l as OTOR '5 RT- ast C 42 INTERFACE Z moo 56 DATA RATE LANDING CONVERTER LIMIT SWITCHES 60 5 H812 IN H Z HATCHWAY N RM 34 6 52, TlMlNG I E!" To HALL 3e DOOR FLOOR @256 388 OPERATOR SELECTOR T LANTERNS 2nd LANDING OPERATOR 1 I L54 MOTOR SPEED -01 TANCE uUNTROLLtR EQEEEQ Rises 50 48 56 Is? LANDING L DEP1PE| CI%R Q 1; y -64 u se DEEI'EICTOR ELEVATOR SYSTEM BACKGROUND OF THE INVENTION 1. Field of the Invention The invention relates in general to elevator systems, and more specifically to elevator systems which employ serial handling of floor related information.
2. Description of the Prior Art Certain economies may be realized in elevator control systems by handling floor related data serially, instead of in parallel. Application Ser. No. 254,007, filed May 17, 1972, now U.S. Pat. No. 3,750,850 which is assigned to the same assignee as the present application, discloses a new and improved floor selector for an elevator system which handles corridor and car call information serially. As pointed out in co-pending application, Ser. No. 340,614, filed Mar. 12, 1973, which is assigned to the same assignee as the present application, certain parts of the elevator system such as the traveling cable, are susceptible to electrical noise, and data transmission over these portions of the elevator system is thus limited to a predetermined maximum rate in order to assure error-free transmission. Thus, serial transmission of car calls over the traveling cable may be limited to a relatively slow data rate, such as 500 Hz. While this relatively low data rate is satisfactory for the majority of elevator installations, it is possible to have an installation in which the maximum car speed and minimum distance between two adjacent landings is such that the relatively slow data rate is not high enough to permit the floor selector to select a floor for stopping. This situation occurs if the floor or landing can be passed during the time between successive appearances of data for the floor concerned.
De-serialization of the data for the critical floors requires additional hardware, and it is not a solution which is easily implemented. If all of the floors of the associated structure are below the minimum height and thus critical, all benefit of serial data handling would be lost by this de-serialization.
SUMMARY OF THE INVENTION Briefly, the present invention is a new and improved elevator system which permits serial handling of floor related information without regard to floor spacing and car speed, and without de-serialization of information, by providing higher speed images of the serial corridor and car call signals. The relatively slow data rate signals are used in that part of the elevator system which requires the slower data rate, and just prior to the point where these signals would ordinarily enter the floor selector, they are directed to a new and improved rate converter. The rate converter provides the high speed images of the serial call signals, and the high speed images are used in the floor selector.
In a preferred embodiment, a shift register is used to provide the high speed image of a serial call signal. A first scan counter creates the basic or regular rate scan slots by repetitively counting through a group of binary numbers, with the counting being used to clock the data rate. The landings are assigned to predetermined different counts. A second scan counter creates high speed clocking by counting through the group of binary numbers at a much higher rate. The minimum rate is that rate which enables the high speed scan counter to count through all of the counts assigned to the landings while the regular rate scan counter is on a single count, and if the call information does not occupy the complete basic scan slot, the high speed scan counter should scan the counts assigned to the landings while the regular rate scan counter is on that portion of a single basic scan slot in which a call might appear.
A comparator responsive to the outputs of the regu- Iar rate and high speed scan counters provides a signal each time their counts are equal, which signal is used to enter data from a serial regular rate call signal into the high speed shift register.
BRIEF DESCRIPTION OF THE DRAWINGS FIG. 3 is a graph which illustrates the output waveforms of a high speed scan counter used to generate timing signals for the rate converter; and
FIG. 4 is a graph illustrating waveforms which aid in understanding the invention.
DESCRIPTION OF PREFERRED EMBODIMENTS To simplify the presentation of the invention it will be described relative to the elevator system disclosed in the following U.S. Pats. which are assigned to the same assignee as the present application, and these patents are hereby incorporated into the present application by reference:
I. U.S. Pat. No. 3,750,850, Ser. No. 254,007, filed May, 17, I972. 2. U.S. Pat. No. 3,804,209, Ser. No. 340,618, filed Mar. 12, 1973.
Referring now to the drawings, and FIG. 1 in particular, there is shown an elevator system 10 constructed according to the teachings of the invention. Elevator system 10 includes an elevator car 12, the movement of which may be controlled by a system processor 11. Since each car ofa bank of cars, and the controls therefor, would be similar in construction and operation, only the controls for a single car I2 are illustrated.
More specifically, car 12 is mounted in a hatchway 13 for movement relative to a structure 14 having a plurality of landings, such as 30, with only the first, second and thirtieth landings being shown in order to simplify the drawing. The car 12 is supported by a rope 16 which is reeved over a traction sheave 18 mounted on the shaft of a drive motor 20, such as a direct current motor as used in the Ward-Leonard drive system, or in a solid state drive system. A counterweight 22 is connected to the other end of the rope 16. A governor rope 24 which is connected to the top and bottom of the car is reeved over a governor sheave 26 located above the highest point of travel of the car in the hatchway l3, and over a pulley 28 located at the bottom of the hatchway. A pick-up 30 is disposed to detect movement of the car 12 through the effect of circumferentially spaced openings 26A in the governor sheave 26. The openings in the governor sheave are spaced to provide a pulse for each standard increment of travel of the car, such as a pulse for each 0.5 inch of car travel. Pick-up 30, which may be of any suitable type, such as optical or magnetic, provides pulses in response to the movement-of the openings 26A in the governor sheave. Pickup 30 is connected to a pulse detector 32 which provides distance pulses for a floor selector 34. Distance pulses may be developed in any other suitable manner, such as by a pick-up disposed on the car which cooperates with regularly spaced indicia in the hatchway.
Car calls, as registered by push button array 36 mounted in the car 12, are recorded and serialized in car call control 38, and the resulting serialized car call information is directed to the data rate converter 100.
Corridor calls, as registered by push buttons mounted in the corridors, such as the up push button 40 located at the first landing, the down push button 42 located at the thirtieth landing, and the up and down push buttons 44 located at the second and other intermediate landings, are recorded and serialized in corridor call control 46. The resulting serialized corridor call information is directed to the system processor 11. The system processor ll directs the corridor calls to the data rate convertets of the various elevator cars via an interface circuit associated with each car, shown generally at 15, to effect efficient service for the various floors of the building and effective use of thecars.
The data rate converter 100 provides high speed images of the serial corridor and car call signals, and these high speed call signals are directed to the floor selector 34. The floor selector 34 processes the distance pulses from pulse detector 32 to develop information concerning the position of the car 12 in the hatchway l3, and also directs these processed distance pulses to a speed pattern generator 48 which generates a speed reference signal for a motor controller 50, which in turn provides the drive voltage for motor 20.
The floor selector 34 keeps track of the car 12 and the calls for service for the car, it provides the request to accelerate signal to the speed pattern generator 48, and provides the deceleration signal for the speed pattern generator 48 at the precise time required for the car to decelerate according to a predetermined decelera tion pattern and stop at a predetermined floor for which a call for service has been registered. It will be appreciated, however, that since the floor selector handles floor associated data, such as corridor and car calls and the serial advanced car position, serially, that the elevator car must not sweep past a floor between successive appearances of data relative to that floor. In the incorporated applications, the data rate used in the floor selector 34 is set by the noisiest" part of the data transmission system, which is the traveling cable interconnecting the car station in the elevator car with the possible for the floor selector 34 to select floors for stopping without regard to car speed and floor spacing, and without restoring to de-seri'alization of floor related data for the floor, or floors, which have the critical spacing. The data rate converter creates high speed images of the corridor and car call signals, and also generates the high speed timing signals and strobes necessary to use the high speed serial car and corridor call signals.
The floor selector 34 also provides signals for controlling the door operator 52, and it controls the resetting of the car call and corridor call controls when a car or corridor call has been serviced. The floor selector 34 also provides the signals for controlling the hall lanterns 54.
Landing, and leveling of the car at the landing, may be accomplished by a hatch transducer system which utilizes inductor plates 56 disposed at each landing, and a transformer 58 disposed on the car 12.
The motor controller 50 includes a speed regulator responsive to the reference pattern provided by. the speed pattern generator 48. The speed control may be derived from a comparison of the actual speed of the motor and that called for by the reference pattern by using a drag magnet regulator, such as disclosed in US. Pats. 2,874,806 and 3,207,265, which are assigned to the same assignee as the present application. The precision landing system using inductor plates and transformer 58 is described in detail in patent 3,207,265.
An over speed condition near either the upper or lower terminal is detected by any suitable arrangement, such as by the combination of a pick-up 60 and slowdown blades, such as a slow-down blade 62. The pickup 60 is perferably mounted on the car 12, and a slowdown blade is mounted near each terminal. The slowdown blade has spaced openings, such as a toothed edge, with the teeth being spaced to generate pulses in the pick-up 60 when there is relative motion between them. These pulses are processed in pulse detector 64 and directed to the speed pattern generator 48 where they are used to detect overspeeds.
A new and improved floor selector 32 for operating a single elevator car, without regard to operation of the car in a bank of cars, has been disclosed in the first incorporated US. Pat. Ser. No. 3,750,850. Modification of the floor selector 32 to adapt it to bank operation and control by system processor 11 is disclosed in the second incorporated US Pat. No. 3,804,209.
FIG. 2 is a partially block and partially schematic diagram of a data rate converter which may be used for the data rate converter 100 shown in FIG. 1. ln describing FIG. 2, the graphs shown in FIGS. 3 and 4 will be referred to, as they illustrate waveforms which aid in understanding the invention.
The data rate converter 100 provides hi g h speed images of the serial up corridor call signal lZ, the serial dow r 1 corridor call signal i, and the serial car call signal 3Z. The data rate of these signals is determined by that maximum rate which can reliably be transmitted without error over the noisiest portion of the elevator data transmission system, such as over the traveling cable. In the incorporated patents, this rate was selected to be 500 Hz. In these incorporated patents, a 32 KHz. multivibrator, shown generally at 102 in FIG. 2, provides the basic timing clock, and a plurality of dividers, counters and gates, shown generally at 104, provide the various timing signals and strobes used to properly time the operation of the system which operates by handling floor related information serially. The timing signals generated by the 32 KHz. clock includes SQS S6S, K088, K08, S100, S200, S300, STA, STB, STC, S4, K025 and KPS, all of which are shown in graphs of timing waveforms in the incorporated patents.
The signals SOS-S68 are provided by a seven bit counter which repetitively divides successive predetermined time intervals into a plurality of scan or time slots. For example, the counter is pulsed every 2 milliseconds, thus making a complete scan of its 128 possible states in 256 milliseconds. Each floor of the building the elevator system is associated with is assigned to a particular count of this counter, with the counts being referred to as scan or time slots, each of which are of 2 milliseconds duration. Each floor of the building is thus assigned to a specific scan slot, but each scan slot does not necessarily designate a floor level. For example, some scan slots may be used to designate when a car is in an express zone, and some scan slots may be unused.
When signals SOS-86S are outputting a particular binary count, such as the binary count for 63, information relative to the landing assigned to binary count 63 is transmitted. The information does not necessarily have to occupy a complete scan slot. As illustrated in FIG. 4, the serial can call signal 3Z includes information indicating a car call in the last seven-sixteenths of the scan slot.
In providing a high speed image of a serial corridor or car call signal, the minimum speed selected is not determined by the data rate necessary to assure that the car will not sweep past the floor between successive appearances od data relative to that floor, but is determined by multiplying the rate of data to be translated into a high speed image times the number of scan slots in the basic count group, and dividing the resulting product by that portion of a scan slot during which the data is valid. Thus, if the basic system operates at 500 Hz. and the scan counter repetitively counts through 128 scan slots before resetting the counter to zero, and the data is valid over seven-sixteenths of a scan slot, the minimum rate of the high speed image is:
n: 500 x 128/7/16= 14 KHZ The maximum rate is set by the component of the circuitry having the lowest operating speed, and will generally be about 1 MHz. This minimum frequency of 146 KHZ will enable each presentation of data at'the slow rate to update the appropriate high speed scan slot since all of the high speed scan slots will appear while valid data for a floor is being presented in a basic scan slot. In general it would be advisable to provide a higher frequency than the minimum frequency in order to insure that all of the high speed scan slots appear at least once during each presentation of valid data. For purposes of example, a high speed data rate of 320 KHz will be used, which is 640 times faster than the 500 Hz data rate. This will enable the high speed rate to count through 128 high speed scan slots five times during one basic scan slot, and over twice during the sevensixteenths of a basic scan slot that the data is valid.
To achieve the exemplary 320 KHz data rate, a 5.12 MHz. multivibrator 106 is provided, the output of which is applied to dividers, counters and gates, shown generally at 108, to provide the high speed counts and strobes necessary to operate the floor selector 34 at the 320 KHz. data rate.
FIG. 3 is a graph which illustrates l /5 of a basic scan slot, and the 128 high speed scan slots which are generated during this 0.4 millisecond time period. The scan slots are generated by a binary counter responsive to the 5.12 MHZ. multivibrator, with the output of the counter being illustrated in FIG. 3 as signal HSSO- S-HSS6S. The HS prefix indicates that the following signal is 640 times faster than the signal identified with those letters in the incorporated applications.
The serializers for the corridor and car calls at the basic 500 Hz. rate may be conventional multiplexers which assemble parallel data and serialize it into the time or scan slots assigned to the landings the data is associated with. The high speed serializers, however, must increase the speed of the relatively slow speed serial call signals. The data is received at the 500 Hz. rate, and thus the slow speed signals cannot simply be increased in speed to the desired rate.
The invention creates a high speed image of the lower speed signal, which high speed image operates at the high speed rate selected, and as the slower speed data becomes available it is used to update the high speed image of the slower regular rate signal. During the time no data is available for updating, the high speed image is recirculated without change. When the data signal becomes available, it is used to correct, if necessary, the data in the high speed scan slot which represents the regular scan slot currently .being presented.
The high speed serializers used in data rate converter are shift registers. Shift registers 100, 112 and 114 provide high speed images gf th e up an d down corridor call and car call signals 12, 2 Z and 3Z, respectively, which hi h speed signals appear at output terminals and HS3Z, respectively.
Since in the example, 128 basic scan slots are used, which number will handle an elevator system for the tallest structure known to date, the high speed image must also have at least 128 scan slots and thus the shift registers 110, 112 and 114 must each have at least 128 bits. An example of a suitable shift register is the MOS- TEK type number MK1002P. As disclosed in the incorporated applications, the scan counter which develops the scan slots may also be programmed to count to 64, 32 or 16, for those systems which do not require 128 scan slots. The present invention is applicable to any number of scan slots in the basic scan group. If a 128 bit shift register is used for systems having 16, 32 or 64 scan slots, the data would simply be repeated eight, four or two times, respectively, in the shift register.
Each of the shift registers includes a clock input C for establishing the shift rate, a data input D, an enable input E, and an output OP. The clock inputs are connected to the timing block 108 to obtain a clock signal which will shift the shift register at the desired high speed rate, which in the example chosen for illustration will be 320 KHz.
The data inputs D are connected to receive the serial regular speed signal it is tgprovigg a high speed image of. The serial signals 12, 2Z and 32 are applied to their associated shift registers I10, 112 and 114, respectively via input registers 116, 118 and 120, respectively. Input registers 116, 118 and 120 may be D-type edge triggered flip-flops, such as Texas lnstruments type number SN7474, which transfers input information appear ing at input D to output Q on the positive edge of a clock pulse applied to immt C.
The serial signals 12, 2Z and 3Z are connected to the D inputs of the input registers 116, 118 and 120, respectively, via inverters or NOT gates 122, 126 and 134, respectively.
The input registers 116, 118 and 120 are clocked at the same 320 KHZ. rate used for the shift registers 110, 112 and 114, but the clock for these input registers is shifted forward or advanced in phase compared with the 320 KHZ. clock applied to the shift registers, in order to insure that none of the information in the input signals is missed. This 320 KHZ. shifted clock signal, used to clock the input registers, is applied to the C inputs thereof.
The data from the scan slots of the relatively low rate serial signals a 2 Z and I? is transferred into corresponding scan slots in the high speed serial image signals W2, H522 and H832, respectively, by comparing the count SOS-S6S of the counter 104 which establishes the regular rate scan slots, with the count HSSO- S-HSS6S of the counter 108 which establishes the high rate scan slots, in a comparator 136, such as two 4-bit comparators (Texas Instruments SN7485, for example). When the counts of the two counters are equal, the A B output of comparator 136 goes high, and this high or true signal is used to enable update of the data in the shift registers 110, 112 and 114. If the input data occupies a complete regular scan slot, the A B output of comparator 136 could be directly connected to the enable inputs E of the shift registers. In the elevator system disclosed in the incorporated patents, the data is valid for only the last seven-sixteenths of each scan slot assigned to a floor. This portion of the scan slot is identified by using clock signals KPS and K025 from the timer block 104, and a D-type edge triggered flip-flop 138, which may be similar to the input register flipflops. It will be noted from FIG. 4 that clock KPS is high for the last one-half of each scan slot, and clock KO2S is high four times during each regular rate scan slot. Clock KPS is applied to the D input of flip-flop I38, and it is clocked to the Q output by clock KO2S. Thus, the valid data period, illustrated in FIG. 4, appears as a true Q output from flip-flop 138.
A three input NAND gate 140 and a D-type edge triggered flip-flop 142 are utilized to provide the true enable signal for the E inputs of shift registers 110, 112 and 114. The A B output of comparator 136 is connected to one input of NAND gate 140, the clock signal KPS is connected to another of its inputs, and the 0 output of flip-flop 138 is connected to the remaining input. The output of NAND gate 140 is connected to the D input of flip-flop 142. The clock input C is connected to the same 320 KHZ. shifted clock as the input registers 116, 118 and 120, and the Q output of flipflop 142 is connected to the enable inputs E of shift registers 100, 112 and 114. r
The outputs OP of shift registers 110, 112 and 114 are connected to output terminals HSlZ, H522 and HS3Z via inverters 144, 146 and 148, respectively.
Thus, when the high speed scan slot is on the same count number as the regular rate scan slot, and the regular rate scan slot is that portion thereof which contains valiidata. the output of NAND gate 140 goes low and the 0 output of flip-flop 143 goes high to enable the Q outputs of flip-flops 116, I18 and 120 to update the corresponding high speed scan slot with the data then occurring in the regular rate scan slot. In the absence of a true enable signal at the E inputs of the shift registers, the data is recirculated in the shift registers without change, awaiting the next valid data period for updating the high speed scan slot corresponding to the next basic or regular scan slot.
For purposes of example, it will be assumed that the regular scan slot corresponding to binary count 63 contains a car call. Thus, as illustrated in FIG. 4, the serial car call signal 3Z will be high for the last sevensixteenths of this scan slot. In the example, the outputs I-ISSOS-I-ISS6S of the high speed scan counter, which are shown in FIG. 3, count through 128 bits five times during one regular scan slot. As illustrated in FIG. 4, count 63 of the high speed scan counter occurs twice during the valid portion of the scan slot. Thus, the high speed scan slot corresponding to count 63 will be updated twice while the 32 signal persists, with the second updating being redundant.
In summary, there has been disclosed a new and improved elevator system which enables each part of a serial data system to operate at a suitable rate. Specifically, the new and improved elevator system permits the serial data rate in the floor selector to be higher than that of the data transmission system. The serial data rate of the transmission system is necessarily limited due to system noise and this limitation becomes critical in the floor selector of high speed elevator systems in which floor spacing is such that the car can sweep past a floor in less time than it takes to serially scan all of the time slots assigned to the floors. The invention discloses the connection of a data rate converter between the data transmission system and the floor selector, which converter provides a high rate image of the regular rate serial data signals. The high speed data rate is selected such that all of the high speed scan slots are scanned at least once during the period of each regular scan slot that valid data is being transmitted. Thus, presentation of valid data at the regular rate results in updating the corresponding high speed scan slot.
I claim as my invention: 1. An elevator system comprising: a structure having a plurality of landings, an elevator car mounted in said structure to serve at least certain of the landings, call registering means for registering landing related calls for elevator service, first serializing means responsive to said call registering means, said first serializing means serializing said landing related calls to provide a first serial signal in which the calls for elevator service appear according to the landings to which they are related,
second serializing means responsive to said first serial signal, said second serializing means providing a second serial signal which is a higher speed image of said first serial signal,
and means responsive to said second serial signal for controlling said elevator car to serve the calls for elevator service.
2. The elevator system of claim 1 wherein the first serial signal includes a plurality of landing related time intervals which occur at a predetermined first rate, and the second serial signal includes a plurality of landing related time intervals which occurs at a predetermined second rate, with the first and second rates being selected such that all of the landing related time intervals of the second serial signal occur at least once during each landing related time interval of the first serial signal.
3. The elevator system of claim 1 wherein the first serial signal includes a plurality of landing related time intervals which occur at a predetermined first rate, with a landing related call occupying a predetermined portion of the time interval related to the same landing, and the second serial signal includes a plurality of landing related time intervals which occur at a predetermined second rate, with the first and second rates being selected such that all of the landing related time intervals of the second serial signal occur at least once during the predetermined portion of a time interval of the first serial signal-which may include a call for elevator service.
4. The elevator system of claim 1 wherein the first and second serializing means include first and second counting means, respectively, which clock the first and second serial signals, respectively.
5. The elevator system of claim 4 wherein the first counting means counts through a predetermined group of numbers at a first predetermined rate, with the landings being associated with predetermined numbers of the group, the second counting means counts through the predetermined group of numbers at a second predetermined rate, said second predetermined rate being selected such that the second counting means counts through the group of numbers at least once while the first counting means is on each number of the group, and means coupling the first serial signal and the second serializing means during the time the second counting means is on the same number as the first counting means, to update the second serial signal at the rate of the first counting means.
6. The elevator system of claim 4 wherein the first counting means counts through a predetermined group of numbers at a first predetermined rate, with the landings being associated with predetermined counts of the group, and with a call for elevator service associated with a landing appearing in the first serial signal during the count of the first counting means associated with this landing.
7. The elevator system of claim 6 wherein the second counting means counts through the predetermined group of numbers at least once during the portion of each count of the first counting means which corresponds to the location where a call for elevator service for an associating landing would be located in the first serial signal, and means coupling the first serial signal and the second serializing means when the counts of the first and second counting means are equal, to update the second serial signal during each count of the first counting means.
8. An elevator system, comprising:
a structure having a plurality of landings,
an elevator car mounted in said structure to serve the landings,
call registering means for registering landing related calls for elevator service,
first counting means repetitively counting through a predetermined group of numbers at a first predetermined rate, each of said landings being associated with a different count,
first serializing means responsive to said call registering means and to said first counting means, said first serializing means providing a first serial signal in which a call for elevator service appears when the first counting means is on the count associated with the same landing the call for serivce is associated with,
rate converter means providing a second serial signal which is a higher speed image of the first serial signal,
and selector means responsive to said second serial signal for controlling said elevator car to serve calls for elevator service.
9. The elevator system of claim 8 wherein the rate converter means includes second counting means repetitively counting through the predetermined group of numbers at a second predetermined rate which is selected such that the second counting means counts through the group of numbers at least once during the time a call for elevator service appears in the first serial signal, comparator means responsive to the first and second counting means and providing a signal when the counts of the first and second counting means are equal, and second serializing means providing the high speed image of the first serial signal in response to the first serial signal, to said second counting means, and to the signal provided by said comparator means.
10. The elevator system of claim 9 wherein the second serializing means includes a shift register clocked by the second counting means.
11. The elevator system of claim 9 wherein the second serializing means includes an input register for storing calls for elevator service from the first serial signal and a shift register, with said input and shift registers being clocked by the second counting means, and wherein a call for elevator service stored in the input register is transferred into the shift register when the comparator means provides a signal indicating the counts of the first and second counting means are equal.
12. An elevator system, comprising:
a structure having a plurality of landings,
an elevator car mounted for movement in said structure to serve at least certain of the landings,
call registering means for registering landing related calls for elevator service,
first serializing means serializing said landing related calls to provide a first serial signal for transmission of calls at a rate consistent with system electrical noise,
rate converter means providing a second serial signal which is a higher speed image of said first serial signal for transmission of calls at a rate consistent with the maximum speed of the elevator car and the minimum distance between two adjacent landings,
14. The elevator system of claim 12 wherein the rate converter means includes second serializing means and means effectively coupling the first serial signal and second serializing means to update the second serial signal only when the first and second serial signals are simultaneously presenting information relative to the same landing.
l= k i