Elevator control system - Patent Review 5042620

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BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a control system for an elevator.

2. Summary of the Prior Art

The technology of elevator control systems is becoming increasingly complex as attempts are made to provide a more responsive system to the users of the elevator. Thus, JP-A-56-75365 and JP-A-58-104880 discuss devices in which an indication is made when an elevator cab is fully packed with passengers, and therefore will pass and not stop at certain floors. Furthermore, JP-A-57-38277 shows a device which indicates the amount of space within the elevator cab, to inform users how many more passengers can get in. Furthermore, it is common for a device located at the user's floor to indicate the position of the cab in response to a call, such as those described in JP-A-49-1260, JP-A-56-88081, and JP-A-52-126850. It is also possible to indicate at which floors the elevator cab will stop, and such as described in JP-A-50-124067, JP-A-63-87435 discloses a network system in which the signal control channels connect each other. JP-A-60-23270 is concerned with an elevator maintenance system.

In all such systems, the problem is the increasing complexity of the interlinking of the various devices of the control system. The present invention is concerned with configurations which seem to overcome, or at least reduce the interconnection of the components of the system.

SUMMARY OF THE INVENTION

The present invention has a number of aspects. As mentioned above, each aspect is concerned with the interconnection of the various components of the elevator control system, and we will first discuss those components.

In general, any elevator system according to the present invention will have a plurality of elevator information generation devices, each of which devices has an information output unit for outputting elevator information. Some of those elevator information generation devices may be in the elevator cabs themselves, but others may be positioned e.g. at the floors at which the elevator cab is to stop. Similarly, in order to provide information to the user, the control system will have at least one (normally more) displays for providing an elevator display.

Furthermore, in general, the system will have an elevator control which receives the elevator information from the information output unit of the elevator information generation devices, and generates elevator control signals.

In a first aspect of the present invention, a display controller is connected to the information output of the information generation devices, and that display controller generates display control signals which control the display(s). The system may have a plurality of display controllers connected to the information output of the elevator information generator devices by a common transmission path, or there may be a single display controller, again connected by a common transmission path. This common transmission path is important as it simplifies the interconnection of the system, and thus second and third aspects of the invention are concerned with the presence of such a common transmission path, interconnecting the display controller and the elevator information generation devices. These second and third aspects, therefore are independent of the elevator controller.

Where an elevator controller is provided, however, that elevator controller may determine the time of transmission of the elevator information to the elevator controller and the display controller and this is the fourth aspect of the present invention.

In more complex systems, it may be necessary to provide separate elevator controllers for each elevator, and in that case a superviser controller may be provided for supervising the elevator controller. In this case, a common transmission path may interconnect the elevator controllers, the superviser controller and the display controller(s).

Other aspects of the invention are concerned with the methods of operating the system, the display system within the elevator system, the method of installation, and the overall elevator system.

The present invention simplifies the control of display devices representing information about the movement of the elevator cab(s). On average, an elevator takes 7 seconds to reach a given floor, 2.5 seconds to open the door, 2 to 12 seconds for passengers to step in and out of the cab, and 3 seconds for the door to close. Since this may occur at an unknown number of floors between one user and the initial position of the cab, waiting for the cab involves an unknown delay. It is affected by the length of time the door stays open, and therefore the number of passengers who enter or leave the cab. If the user is not provided with information concerning the movement of the cab, it is easy for him to become irritated because of the uncertainty in the delay.

Conventional elevator control systems generally do not include data concerning door opening and closing or the running position, i.e. the data for the time required to close the door and start to move to another position. Because of the complexity, conventional elevator systems cannot successfully control several elevator cabs, and faulty operations develop in the programming of the movement which does not assist the user.

In the prior art, there is generally a direct link between the elevator controller and the corresponding display, but this leads to the problem that, where several elevator controls are provided, one display can be linked to another, and furthermore the control for the display, such as display timing etc has to be controlled from within the elevator and this makes the circuitry more difficult. In the present invention, the use of a display controller, preferably connected to the elevator controllers by a common transmission path, simplifies the control of the display. Since the display controller may be varied, it becomes easier to control variations in the displays desired. This is important because the type of information that needs to be displayed is often a matter of fashion, and it is desirable that the elevator display system can be up-dated when desired.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the invention will now be described in detail, by way of example, with reference to the accompanying drawings, in which:

FIG. 1 illustrates parts of elevator control system forming an embodiment of the present invention;

FIG. 2 illustrates the interconnection of parts of the elevator control system;

FIG. 3 shows a cab operation control data table;

FIGS. 4 and 5 show information control data tables;

FIG. 6 shows an information guidance rule table;

FIG. 7 shows a cab control circuit;

FIG. 8 is a flow-chart of elevator operation according to the present invention;

FIG. 9 is a diagram of a circuit for door position;

FIGS. 10 to 12 show elevator displays;

FIGS. 13 and 14 are flow-charts of information processing in a system according to the present invention;

FIG. 15 shows the format of data;

FIG. 16 shows other data formats;

FIG. 17 shows a transmission control data table;

FIG. 18 shows the transmission timings;

FIG. 19 is a flow-chart of data processing;

FIG. 20 shows a part of the data header of the format of FIG. 16; and

FIG. 21 shows a further information display.

DETAILED DESCRIPTION

FIG. 1 illustrates a constructional view of an elevator signal control system according to the present invention. FIG. 1(a) shows an example of a signal control system applied to the situation where there is a single elevator cab. The system has an operation control channel C1 consisting of an elevator operation controller CE1 and a control commander CU1 that selects the operation control rule or the monitoring of the control state. The operation controller CE1 and control commander CU1 are connected to each other by a connected transmission path CN10 in the signal control channel network. The system also has an information control channel S1 consisting of an information inputter IF1 and an information control channel CS1, which are connected to an information channel network transmission path SN10. The information inputter IF1 inputs and selects the information, designates the information guidance rule, and receives the data from an information center. The information control channel S1 is connected to the operation control channel C1 via the information network transmission path SN10.

The elevator operation control channel C1 transmits data that provides basic control information to the three other devices CU1, IF1, and CS1 through the above network transmission paths. The three devices CU1, IF1 and CS1 receive the data at the same time. This transmission arrangement does not increase the volume of data transmission through the network transmission path CN10 and SN10 but increases the time required for editing the data output from the elevator signal control channel CE1. However, this effect is not a disadvantage in the signal control channel if the information input device IF1 is designed to use only the information network transmission path SN10 in outputting the data to the information control channel CS1.

FIG. 1(b) shows an example of an elevator operation control system for two cabs consisting of an information guidance control system that has an individual guidance device at each floor and an information guidance controlling unit to control all of the system channels, where the combined method for transmitting the data for mechanical and effective control of two elevator cabs plus the data for information control channel CS1 is the same as in FIG. 1(a). However, since the information control channel CS1 receives data directly from the information center independent use of the network transmission path CN10 can satisfy the purpose of sending the data.

FIG. 1(c) shows an example where the present invention is applied to an elevator group control system for eight cabs. In FIG. 1(c), the operation control channel C1 has eight sub-channels CE1 to CE8 for the eight cabs and similarly the information control channels S1 has eight sub-channels SE1 to SE8. There is shown the construction of an elevator signal control system including an operation control channel C1, as information control channel S1, and a maintenance channel H1.

When the operation signal control sub-channel CE1 of the first elevator cab outputs operation data to a supervisor controller in the form of a group control device M10 via the network transmission path, the information guidance control sub-channel SE1 assigned to the first cab receives it at the same time.

Likewise, when the group control device M10 outputs service data to the operation signal sub-channel of the eighth cab CE8 to supply information concerning operating conditions at a service floor, a hall-call or other items of service, the information guidance sub-channel SE8 and the maintenance channel H1 that consists of the elevator operation watcher K1, the user commander U1, and the trouble shooter T1 receive the same data at the same time.

The information channel S1 consists of the basic information control sub-channels SE1 to SE8 and the hall guidance control channels SC1 and SC2 that operate the inter-building information devices provided at the entrances of the elevator halls to display guidance information about the floors presently in service and/or event(s) presently held in the building. This channel receives data output from every floor one after another and selects information data generated by an external information input device IF2.

The transmission path N10 takes a complete double channel system to use the operation signal control channel or the information channel individually, because of the high independence of the channels.

FIG. 2 shows a general physical constructional view of the systems of FIG. 1(c), except that the information control sub-channels SE2 to SE8 respectively assigned to the second to eighth elevator cabs and the elevator operation signal control sub-channels CE2-CE8 again assigned to the second to eighth elevator cabs are omitted for the sake of clarity.

The operation control channel C1 consists of group control device M10 and the elevator operation control sub-channel assigned to each of the eight cabs (only sub-channel CE1 being illustrated).

The elevator operation control sub-channel CE1 assigned to the first cab consists of an elevator control system C10 connected to the transmission path by a suitable interface I, a cab door open-close device C20, a door open-close driver device C50, a cab interface terminal device C60, and a floor interface terminal device H6A.

The information control channel SE1 of the first elevator cab which forms a part of the information channel S1 consists of an information control device S101 and a transmission path S10, which intake the data from the network transmission path N10 to form that data into a signal and outputs that signal to drive the hall information guidance devices H1F1 to H9F1. These display information based on the data in LED display boards or in speaker devices.

Building managers can make use of the user command board UCB in the maintenance system H1 to input or alter the information guidance program, elevator operation mode, timing, and the extent of cab service with its appearance in the information guidance devices (Major signals for the assignment are illustrated in the user command tables in FIG. 5). Such managers can monitor the state of the elevator cabs in service and the performance of each cab in passenger service.

The data in a general purpose information table USTBL (see FIG. 5) is output from the user command board UCB, to show e.g. a weather forecast (data predicted by US1 in FIG. 5) or traffic guidance information such as a train time table or the time a taxi would take to reach stations (data indicated by US3 in FIG. 5) for the convenience of the passengers of the elevator. That output data is passed to the information network transmission path N10 and reaches each of the control devices (S101, C10, M10) simultaneously.

The maintenance channel H1 also has a remote control maintenance system MAS, which is a double function device including the information input device IF2 and the trouble shooter device T1 mentioned above in FIG. 1(c). This may be connected to the service center by a telephone line TEL3 for service, maintenance, and general information.

A sensor P6F1 generates information indicating how many passengers are waiting at a cab doorway located at the 6th floor. Similar sensors (not illustrated) are provided on the other floors. The sensor P6F1 supplies a data signal indicating how many passengers are waiting at the hallway to every device of M10, C10, and C20 via the I/O transmission path L10. This signal may be connected via the information transmission path S10 when required by the first elevator cab information control channel SE1 in some cases.

In a similar way FIG. 2 illustrates other elevator information generation devices on the sixth floor (again similar devices being provided on other floors).

It can be seen that the group control device M10, the user command device UCB, the network transmission path N10 and the remote control maintenance device MAS are used in common but other functions individually would require a system with as many devices as elevator cabs. FIG. 2 also shows hall door D6F1, being the door at the elevator doorway on the 6th floor.

The group control device M10 receives the button's hall-call signal from an interface terminal device H6A located at the cab doorway of every floor, selects and designates the service elevator by the method discussed later with reference to FIG. 8 and that mentioned in the official gazette Toku Kai Sho 59-223672, and transmits service instruction for responding to the hall call signal KDH to the designated cab control device C10.

FIG. 3 illustrates the tables contained in each device (C10, M10, UCB, MAS and S101) for storing the data acquired through the network transmission path N10 between the group control device M10 and the elevator operation signal device C10. The data table CMTBL of the cab stores data output from the network transmission device C160 of the elevator control device C10 shown in FIG. 7 (to be discussed later). The signal is received not only by the group control device M10 but also simultaneously by the remote control device MAS, the user command device UCB and the information control device S101.

All of the signal intake devices prepare table CMTBL corresponding to the number of the intake devices. The CACD-CWG has memory of 1 byte in general, but the cab calling CC has to have 8 bytes at the 64th story. The byte for door opening requires only 1 bit each for signals COPEN-CCLLCS.

Likewise, the group control data table MTBL taking charge of overall common information output from the group control device M10 and the individual control instruction data table MCTBL taking charge of individual elevator cab simultaneously not only to the elevator operation signal control device C10 that covers the first to eighth cabs but also to the information guidance control device S101.

This way of constructing the network transmission gives the advantages of (1) diminution of process on the output force at each device, (2) combination of informational channel and operational signal channel by means of the network transmission path, and (3) independent designing, enhancement of performance and remodelling of the informational channel. The transmission format shown in FIG. 16 takes charge of control on the transmission data output from the control table shown in FIG. 17 in determining if the data is necessary or not for transmission and designating the address of the receiving table. The network transmission path makes an orderly transmission according to the bus use permit signal like the time chart shown in FIG. 18. FIG. 19 represents an example of a process flow in the network transmission path.

FIG. 4 represents the cab operation data table CSTBL output from the first elevator operation control device C10 and the service condition data table MSTBL output from the group control device M10. These signals are necessary for an information control device S101 to generate reports of the service condition of elevator cabs, which are transmitted to the hall information devices H1F1 to H9F1. In addition, an incoming passenger detection signal CINMP indicates a passenger moving to and stepping into cabs during the time the door is open, sensed by the device P6F1 (which detects the movement of waiting passengers) each of which is located at the cab doorway. Alternatively a suitable signal may be generated by a photoelectric device which senses passengers stepping in and out of the cab. This is necessary for representing the pattern D12A or D10A shown in the display illustrated in FIG. 10.

FIG. 5 represents the use command table UCTBL mentioned previously. This is the signal output by the user command device UCB to the information channel C1 and the general information data table USTBL that is the signal output to the individual information control sub-channels CE1 to CE8 of the cabs. The data of the UCTBL is considered to be an important control rule. It should therefore be recorded in an EEPROM to prevent data loss due to loss of power or UCB power failure.

FIG. 6(a) represents a transmission table for recording the information guidance rule USRU in the general information data table USTBL, as stated in FIG. 5.

The information guidance control device S101 of each cab receives the operation rule data in the control schedule to commercial 2 and stores it in a semi-permanent memory device EEPROM or an IC memory card. It thereafter reuses the data, receiving it from the control channel CE1, to generate guidance information following the rule determined by the group tables, as shown in FIGS. 3 and 4. The information guidance control system analyses these tables to see if any of them belong to the rules of the control command SCMD or the service guidance or hall service guidance or elevator cab condition guidance. It also checks to see if any information guidance device displays the data thus selected.

FIG. 6(b) shows an example of the CSM1 table specified in a commercial control system, whose construction is available for all specifications mentioned regarding cab service guidance and further instances.

FIG. 7 is a block diagram representing an example of an elevator operation control device C10.

In FIG. 7, the I/O transmission circuit C110 receives a door open terminal position signal COPLS or cab call button signals K11 to K19, cab door open-close button signals K20, K30 and the safety shoe signal CSHW from I/O transmission path L10. FIG. 7 illustrates the output of the OPEN and CLOSE signals that instruct the door to open or close, the signal to cause the response lamp to light the signal to cause the response lamp light permits a cab call to be answered, the signal for indicating a half-open door and the permit signal for door closing is derived from activation of an open button K20 or a close button K30.

The network transmission control circuit C160 outputs a signal CSTBL which is the data table for operating the individual cab data table CMTBL in the form of serial transmission data TXD and transmits it through the send-and-receive circuit C165 to two transmission paths N10a and N10b.

Output permission signals are indicated at ETa and ETb. A data "1" signal can be substituted for ETa and ETb. Shown at ERa and ERb are signal intake path selection signals (only one of which can be at logic level "1"). The control condition data table MTBL, the control instruction data table MTBL, the control instruction table MCTBL and/or the user command table UCTBL is received through either one of the network transmission paths N10a or N10b.

The send-and-receive circuit C165 controls data transmission in the network transmission path N10, where the data sending and receiving is between the group control device M10 and the information control device S10. This is controlled by the circuit C165. The data play interruption into the information control device S101.

The information control device S101 transmits the data (illustrated in FIG. 15) to individual hall information guidance devices H1F1 to H9F1 independently, following the data transmission path, and controlled by the send-and receive circuit S165. The operation mode selection circuit C140 determining the operation mode number CACD from the signals of the trouble shoot code CTCD, the operation control mode number MACD, the operation control board i.e. the cab interface terminal device C60's operation selection switch. (Refer for detail to the article in Official Gazette Toku Kai Sho 58-119567).

This signal generates a permit signal that determines the specification suit to each control circuit in the general operation control circuit C190 through the operation mode permit instruction circuit C180 and also determines at the same time the door open-close mode instruction CADRCD and the trouble shooting mode instruction CATCD repsectively, which are transmitted to the door open-close signal control circuit C130 and the door open-close permit relay drive circuit C170 as well as the door rationality circuit C120 and the trouble-shooting code making circuit C150.

The door open-close signal permits the relay circuit C170 to include the door rationality check circuit C120 that troubleshoots if a problem occurs at the door open-close control device C20 or the door open-close drive device C50, and turns off the door open-close permit relay (not illustrated) to make it inactive. This prevents the door unexpectedly opening during the cab's normal operation. The signal given for the normal operation is "close torque" under which vibration does not cause the door to open. A faulty semiconductor may let the door open occassionally, however.

The permit relay can cut off the drive voltage at the door open-close drive device C50 when it senses even a small change in the door close position to put on the disc brake in the door open-close drive device C50, to prevent no further door open-close action. The permit relay has a "fail safe" system where the action of other contact points simultaneously can stop the cab from running.

FIG. 8 represents a flow chart of the operation of the control device in improving the guidance of programmed elevator cab services, taking advantage of continuous door open-close position signals.

The process flow starts by determining the initial values for the guidance information in the display devices located at the elevator service floors and in the cab, the arrival program data table to be combined in the group control device M10, but now also it combines with the information guidance control system S101 that covers the waiting time guidance devices (D1 and D4) as shown in FIG. 10, giving improved functioning.

The reason why the signal for the programmed waiting time is not transmitted from the group control device M10 to the information control device S101 via the network transmission path N10 is that the number of data tables would become so large (the amount of data is calculated by the number of elevator cabs (3 to 8).times.number of floors (2 to 40).times.number of operation direction (2) to result in (12 wards--640 wards)) that it would be difficult for the operational channel C1 to accept it. The increase also may induce problems of short times for data processing in the control channel C1 and would cost more to convert into a high speed system. The problem of degradation of the anti-noise properties in the system would also have to be addressed.

FIG. 8 represents the process flow originally used for cutting the "closing button" to promote quick action of the elevator at a service floor, taking a speed cycle of 0.1 to 1 seconds per step for cab motion, where the cab starts at Step M200 and collects the elements to determine the condition of motion at Step M210 and selection of the condition for beginning cab motion at step M220. The process flow first determines if a passenger is stepping in or out of the cab and branches out to Step M250 to make "close button cut" and displays the guidance to intake a passenger stepping in the cab when the cab has arrived at a floor.

Next, the process flow advances to step M260 to declare "reopen available", then to Step M265 to set the initial value which is the time at which the time "STOP" signal passed from door opening is substracted from a presumed arrival time length to cab departure YSTOP.

Next, when the process flow determines that it is at the point at the beginning of door closing (1-2 seconds) and the time the door is in closing motion, the process flow advances to Step M230 to output the signal that instructs to stop the departure signal and stop the guidance display indicating passengers entering the cab.

When the time passes over a programmed stopping time HSTOP, or the congestion inside the cab reaches a predetermined rate HLOD, or the cab door edge is judged too close to a predetermined value (100-300 mm) to cause a large loss of time to make the door reverse action, or if departure has already been indicated, the process flow advances to Step M240 to output the signal to the control channel to ensure the departure and cuts off the action of the door opening button.

At the same time, the information channel acts on the "hall information device" H1F1 to H9F1 to display a visual sign "Please wait for next cab" or "Please take other line" when a cab will soon arrive or a neighbouring cab will soon arrive and to cause the "cabs-interior information device" to display "Ready to depart", "Door will not open" or "Cab delayed, Door will not open" when the door is beginning to close, using audio signs such as a human voice or a chime or a buzzer for guidance.

When it is determined that Step M270 right before door closing is completed, the processing moves to Step M280 to cause the leading cab proceed to the next floor programmed, and uses Step M290 for calculating the time to run to the next stop and inputs the data for the initial value of presumed arrival time.

In this type of elevator operation, some cabs may pass more than one floor, but a waiting passenger will not get angry because he has no knowledge of how the elevator system is working. Any such passenger is advised that he will have a vacant cab in the time displayed on the guidance device.

It is most important for efficient elevator service that a cab first goes to the floor where many passengers are waiting than going to a floor unexpectedly requested by people whose number is unknown. This cab system however, keeps vacant cabs run down to the 1st floor regardless of the number of waiting people, if a cab call has not been made by some one else from other floors.

FIG. 10 shows an example for guidance information displayed in hall guidance device H6F1 fixed to the top part of hall door D6F1 at the time the first cab is at the 6th floor of the building. FIG. 12 depicts the same example accompanied by voice guidance.

FIG. 9 represents the door open-close position presuming circuit S120 that acts as an information device for the door open and stay position SDRP to substitute the door open-stay position device CDRP in the information control device S101 in an emergency where the network transmission path N10 cannot send the door open-close signal (CDRP, CCLTM) to the information control channel of the first cab.

The circuit S120 consists of a door speed presuming circuit S121 that produces door speed data using the open-close instructions COPN and CCLS that form a part of the cab's data table CMTBL, a reverse action detection circuit S122 that senses the door's turning point to reverse its direction by checking the open-close signals, an acceleration selection circuit S124 that makes a presumption of the door's acceleration speed in reverse action based on the data taken from SDRP which is the signal of the continuous door open-close position UDRM, and a door position circuit S123 that integrates the door speed to produce the position and functions to compensate for the door open-close signal by the door open limit switch signal COPLS and the door close limit switch signal CCLS. This determines the door open-close position signal SDRP and outputs it as information data.

The reason this invention may make use of the above-mentioned circuit S120 is as follows: the elevator door speed consists of an arrangement in which the upper limit changes depending on the condition of the door if open or closed, the position it is at, and condition of forward or reverse motion. Circuit S101 allows setting of the door mode UDRM, including the door speed, the acceleration, and the reverse control time, by using the user command device UCB individually for each group control channel of the operation control mode number MACD and traffic demand mode MTRFCD. The door speed presuming circuit S121 makes a presumption of the door speed taking all these conditions in consideration. The signal thus determined is used for selecting the picture element display by determining device D8.

FIG. 10 represents an example of picture elements displayed by the display appearing in the information device H6F1 located at the cab doorway at the 6th floor. The steps tn1 to tn5 illustrates changes in the display of the information device H6F1.

The step tn1 shows the situation where the cab door stays open at the second floor at which a passenger is stepping out the floor being indicated by Pattern D7. The display also indicates by that the cab door is open and pattern D11 shows that a passenger is stepping out of the cab.

Patterns D1 to D4 show triangles illustrating the first cab moving to the 6th floor, those triangles indicating the direction of movement and representations of time to reach the proposed floor. The patterns show the case where the cab moves downward after first moving up. Arrow D43 indicates the order of those operations. Pattern D6 illustrates the present direction of movement the first cab. Patterns D9 and D10 represent the number of passengers.

The animated pictures D10 and D11 illustrate schematically passengers stepping in and out of the cab to indicate that 3 people stepped out at the second floor. This gives a visual understanding of the cab situation that causes a feeling of unconscious relaxation to passengers waiting at the sixth floor of the building. It is a service which will be welcome to busy people in the modern age.

In display of the Pattern D8, the cab frame may be colored in green, the congestion rate in the cab, the passengers in orange or red, the Patterns D4 and D5 green, and the closeness of the elevator (depending on the number of stopping, the difference in floors and the reservation for a downward move) is represented in Pattern D1 and the increase of D4 in the display.

The Pattern D3 and the cab positions illustrated by D6 and D7 may be coloured in yellow. The direction of elevator motion direction is represented by movement of Pattern D6; controlled e.g. by an animation device (FIG. 11-6 D61-D65 or D6 (t.sub.1)-D6(t.sub.3)) or by arranging block line of light (H6F1B) to move up the display (D6a-D6c) to imitate the movement of the cab. Even if Pattern D3 does not have a device for illuminating the lights in order, people would clearly understand the cab motion when three elements were distributed as a set.

The step tn.sub.2 illustrates an animated picture with Patterns D12 and D12A showing three people stepping into an elevator cab at the second floor. There are two ways of checking congestion at other floors; the simple way is to judge it by cab calls, or hall calls and checking the change in the cab load sensor value or the data acquired at the waiting passenger sensor.

Step tn3 represent an animated picture in which D13 shows the door closing. At this time, if the overlapping part of the picture D9 that shows congestion inside the cab, and part D13 (that shows that the door is closing), is colored in yellow or no color (no light) black, a better result display can be expected with better guidance effects and appearance on the LED board, consisting of a two color (red and green) light source.

Another type of elevator system may have a different specification so that the door will reopen when a cab call is made at the second floor for upward motion. (The mode can change over if hall call service mode UHSVN is set by the user command device UCB). However, no elevator is prevented from departing in general.

When the mechanical shoe provided at the tip of a door activates, Pattern D14 of step tn4 represents the reason for door reopening and can make a display at the sixth floor to indicate this to waiting passengers. Furthermore if an elevator is obstructed from departure by the open button K20 of the operation board (provided in the cab interface terminal device) C60 this can be shown e.g. by Pattern D16 of step tn5. If the open button is kept pressed by accident, people waiting at another floor may wonder if the telephone service is out of order or that waiting is hopeless when the elevator system is of conventional type showing only the cab position but no other guidance. However, this syste