JPH0685940A - Remote monitor system for elevator - Google Patents

Abstract

PURPOSE:To improve the reliability and the smoothness of a direct call function by adjusting automatically the gain of a signal level of transmission and reception signals between an in-cage interphone and a monitor center. CONSTITUTION:A monitor terminal equipment side in the remote monitor system for an elevator allows a reference tone generator installed in the elevator cage to generate a reference tone at a prescribed sound pressure level at the connection of a direct talking function, the reference tone is picked up by a microphone 6B of an interphone 6 to form a transmission signal, and a reference tone generator at the monitor center side generates a reference tone of a prescribed sound pressure level, the tone is sent to a monitor terminal equipment through a telephone line 8 as a reception signal, the reference transmission signal and the reference reception signal are given to an A/D converter circuit 24 respectively, from which digital the signal is converted into digital output data with the signal level. Then a proper gain adjustment value is obtained from the output data of the signal level by referring a gain adjustment reference table 26 at an arithmetic operation circuit and the gain of the amplifier circuit is adjusted automatically by the gain adjustment circuit based on the gain adjustment value.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a remote monitoring system for an elevator having a direct-speaking function for making a call between an intercom in an elevator car scattered in each area and a monitoring center by using a telephone line. Regarding

[0002]

2. Description of the Related Art In recent years, the use of elevators has become active,
Not only middle- and high-rise buildings, but also small-scale buildings have been installed, and the number of popular vehicles has become enormous. Elevator, which is the main transportation in the vertical direction,
Daily maintenance and inspection work is indispensable, and a system in which a specialized maintenance staff of an elevator maintenance company visits the site on a regular basis every month to perform maintenance and inspection work, but with the rapid increase in the number of elevators installed, However, it requires a lot of labor to perform maintenance and inspection of all elevators. Therefore, the demand for labor saving and efficiency improvement in maintenance and inspection work has become remarkable, and in order to respond to this, recently, a remote monitoring system for intensively monitoring individual elevators in a remote place has been developed, and particularly recently installed. Elevators tend to make extensive use of this system.

In this elevator remote monitoring system, as shown in FIG. 5, an elevator machine room 1 installed in each elevator installation building is equipped with an elevator controller 2 and a monitoring terminal 3, and both of them are connected by a transmission line 4. In addition, the monitoring terminal 3 is connected by an intercom 6 installed in the elevator car 5 and a tail cord 7. Further, the monitoring terminal 3 is connected to a monitoring center 9 of a maintenance company via a telephone line 8, and information communication can be performed mutually by connecting the line by dial operation.

The functions of this remote monitoring system are roughly classified into the following three types.

(1) Failure Information Notification Function When some failure occurs in the elevator, the elevator terminal 2 of the monitoring terminal 3 collects the information through the transmission line 4 and automatically issues the information to the monitoring center 9. , Transfer information.

(2) Maintenance data reporting function Basic information such as the number of times the elevator is operated is regularly collected,
Information is transferred by establishing a line connection with the monitoring center 9 at regular intervals.

(3) Intercom call function (direct talk function) When the elevator is out of order, passengers trapped in the elevator car 5 and the monitoring center 9 can talk directly with each other, so that the intercom 6 in the car can use the tail cord 7 After being connected to the monitoring terminal 3 in the elevator machine room 1 via the automatic dialing function, the telephone line 8 between the monitoring terminal 3 and the monitoring center 9 is automatically connected by the automatic dial function to enable direct communication.

Among these three functions, particularly regarding (3), when an abnormality occurs in the elevator and a confinement accident occurs in which the passenger is confined in the car, the passenger in the car is prevented from panicking. In order to do so, immediacy, reliability and smoothness are the most required functions. Especially in the recent condominiums, there are many cases where the manager is absent at night, and if the monitoring center cannot be contacted urgently, the passengers' anxiety in the car will be a great deal of concern. It is extremely important in terms of safety that the direct communication function with the monitoring center of the system works properly.

The internal structure of the monitoring terminal 3 for realizing such a direct call function will be described with reference to FIG. 6, and a telephone line processing unit 12 for connecting to the two-line public telephone line 8. The operational amplifiers (operational amplifiers) 13A to 13D for amplifying the transmission signal and the reception signal are compared with the signal levels of the received voice and the transmitted voice, and the higher level of the received voice or the transmitted voice is preferentially switched. A CPU that controls the operation of the transmission / reception switching circuit 14, the intercom connection circuit 15, and each of these circuits, and performs necessary calculations.
16 are provided. Then, the tail cord 7 is connected to the intercom connection circuit 15, and the tail cord 7
Is connected to an intercom 6 installed in the elevator car 5. The intercom 6 includes a speaker 6A and a microphone 6B, and the received voice is the speaker 6A.
Then, the transmitted voice is picked up by the microphone 6B and sent to the monitoring terminal 3.

In such a structure, the intercom 6
In order to directly talk between the monitoring center 9 and the monitoring center 9, the CPU 16 outputs a connection signal 16A indicating selection of an intercom, and the intercom connection circuit 15 receives the connection signal 16A and the monitoring terminal 3 and the tail cord. The intercom 6 in the car 5 is electrically connected via 7. As a result, the monitoring center 9-telephone line 8-monitoring terminal 3-
The call line of the tail code 7-intercom 6 is established.

The telephone line 8 is a two-line type signal line,
The reception signal received from the monitoring center 9 and the transmission signal transmitted from the intercom 6 to the monitoring center 9 via the monitoring terminal 3 are propagated in the same signal line in an overlapping manner. The telephone line processing unit 12 converts the 2-wire type signal into a 4-wire type signal, extracts the reception signal component from the duplicated transmission / reception signal, and puts it on the reception signal line 14A, or from the intercom 6 to the transmission signal line 14B. It has a function of transmitting the transmitted transmission signal to the telephone line 8.

Therefore, the reception signal from the monitoring center 9 is
After passing through the telephone line processing unit 12, operational amplifiers 13A, 13
The signal level is amplified to an appropriate volume range by B, and is output from the speaker 6A of the intercom 6 via the tail cord 7. Similarly, the transmission signal input from the intercom microphone 6B is also input to the monitoring terminal 3 via the tail cord 7, amplified to an appropriate signal level by the operational amplifiers 13C and 13D, and then transmitted through the telephone line processing unit 12. The call is sent to the line 8 so that the user can talk with the monitoring center 9.

By the way, the transmission / reception switching circuit 14 is inserted in order to avoid occurrence of a howling phenomenon in the circuit. This is because the intercom 6 is becoming smaller and more compact, and the one used in recent elevators is 10c.
The main type is a small box type measuring about mx 10 cm x 5 cm.
The distance between the intercom speaker 6A and the microphone 6B is short. Therefore, the received voice that is input from the telephone line 8 and reproduced and output by the speaker 6A is picked up by the intercom microphone 6B and re-input as the transmitted voice, which causes the received signal on the telephone line 8 to wrap around. Not only will the pseudo-speech signal be duplicated, but the leakage of the signal from the transmission system to the reception system in the telephone line processing unit 12 (this is called sidetone) will occur again in the operational amplifiers 13A and 13B. The audio loop phenomenon is amplified and amplified by the intercom speaker 6A, and a howling phenomenon occurs.

Therefore, in order to avoid the howling phenomenon, in the transmission / reception switching circuit 14, the reception signal line 14A
The upper receiving signal and the transmitting signal on the transmitting signal line 14B are input to the comparator 14C, the signal with the higher input level is given priority, and the other signal has a certain loss, generally 30 dB to 7 dB.
A process for giving 0 dB loss is performed.

As a result, for example, the voice output from the intercom speaker 6A when the reception is prioritized is detected as a transmission signal by the intercom microphone 6B, but a loss is given in the transmission / reception switching circuit 14 and the telephone line 8 is used.
It is possible to avoid the adverse effects of the outflow to and the side noise. In addition, when the transmission is prioritized, the side noise causes the telephone line processing unit 12 to sneak into the reception signal line 14A, but since a loss is given to the reception system in the transmission / reception switching circuit 14, input from the intercom microphone 6B The phenomenon that the sound is output from the speaker 6A does not occur. Since the transmission / reception switching circuit 14 is a switching circuit that enables only one of the transmission system and the reception system, when the passengers in the car and the surveillance staff at the monitoring center speak at the same time, either Although the direction is invalid, intercom 6
There is no problem in the circuit through which

In this way, the direct communication function between the intercom 6 in the car 5 and the monitoring center 9 is realized.

[0017]

However, such a conventional elevator remote monitoring system has the following problems. That is, the intercom 6 in the car 5
The call function between the monitoring center 9 and the transmission / reception switching circuit 1
The switching function in 4 avoids problems such as howling and enables smooth calls.
In order to switch the transmission / reception switching circuit 14 by the voice input, it is necessary to achieve it by the voice exceeding the signal level of the priority system, and both the observer of the monitoring center 9 and the passenger in the car can use the daily voice. In order to perform the switching operation of the transmission / reception switching circuit 14 by the input, the comparator 14C is used.
It is necessary that the signal level of the received signal and the signal level of the transmitted signal input to are equal. However, the input signal level of the comparator 14C fluctuates due to the following factors.

(1) Fluctuation of line loss in the telephone line 8 The line loss varies depending on the connection method of the telephone line 8, the length of the route, the conditions at the time of connection due to weather, disaster and the like.

(2) Individual difference of intercom 6 (3) Total extension of tail code Generally, it is said that the volume of a person's voice is about 10 dB around ambient noise. Therefore, in order for the switching operation to be performed by normal voice input, that is, in order for the input signal level of the non-priority system to become higher than the input signal level of the priority system, the signal level of the priority system and the non-priority system at the time of silence are set. The level difference with the signal level is within 10 dB, 5 considering the margin
It is desirable to be within dB.

However, for example, the factor of (1) above is
It may fluctuate from -8 dB to -33 dB,
If you want to control multiple units at once, (2),
The effect of (3) becomes significant. Regarding (2), there is generally a difference in characteristics of 3 to 4 dB even if the same intercom is used, and the effect of (3) cannot be ignored, and especially a building in which multiple elevators are installed in parallel. Then, if the hoistway stroke differs depending on the number of units, the effect will be even greater. Therefore, there is a high possibility that the input signal level difference between the transmission and reception will be much higher than 10 dB instead of 5 dB depending on the connection condition. Due to these factors, the difference between the input signal levels of the transmitting system and the receiving system widens, and the smoothness of the switching operation of the transmission / reception switching circuit 14 is lost. In some cases, the difference exceeded 10 dB, and the call was completely disabled.

Therefore, if the elevator is installed far away from the telephone station and the conditions are not always good and smooth calls cannot be made, it is necessary for a dedicated maintenance staff to visit the site and perform manual tuning. There was a problem that required a lot of labor. Moreover, even if such a measure is taken, it is not sufficient, and the loss at the time of connection varies each time, so there are some cases where the call may be disturbed. In this regard, the conventional CPU 16 controls only the output of the connection signal 16A to the intercom connection circuit 15, and the transmission / reception switching circuit 1
Since the switching operation of No. 4 relies on the fixed gain operational amplifier, there is no flexibility in the communication function with respect to the fluctuation of the input signal level.

The present invention has been made in view of the above-mentioned problems of the related art, and by providing a function of automatically adjusting the amplification factor of a transmission / reception signal, the signal level of the transmission / reception signal is equalized and transmitted. An object of the present invention is to provide a remote monitoring system for an elevator that can smoothly perform the switching operation of the reception switching circuit and enhance the reliability of the direct-speaking function.

[0023]

SUMMARY OF THE INVENTION The present invention provides a direct communication between an intercom in an elevator car and a monitoring center through a telephone line by using a monitoring terminal installed in elevator control devices scattered in each area. In an elevator remote monitoring system equipped with a talk function, a reference sound generator that generates a reference sound of a certain level to be sent through the telephone line is provided on the monitoring center side, and a receiving voice from the telephone line is provided on the monitoring terminal side. An amplifier circuit for amplifying the voice transmitted to the telephone line, a signal transmission / reception switching circuit for comparing the signal levels of the received voice and the transmitted voice, and switching between the received voice and the transmitted voice with priority given to the higher level. An A / D conversion circuit for converting the signal levels of the received voice and the transmitted voice into digital data, and a proximity of the intercom for providing data to the A / D conversion circuit. A gain adjustment reference table and the reference sound generator, the output data of the A / D converter circuit to control the gain control data corresponding thereto installed in the A /
With respect to the output data of the D conversion circuit, an arithmetic circuit for obtaining an appropriate gain adjustment value by referring to the gain adjustment reference table, and a gain adjustment of the amplifier circuit based on the gain adjustment value obtained by the arithmetic circuit. A gain adjustment circuit is provided.

Further, in the elevator remote monitoring system of the present invention, when a plurality of elevators are installed in one building, a reference sound generating device is installed for each elevator car on the monitoring terminal side, and A storage circuit for storing the gain adjustment value obtained by the arithmetic circuit for each elevator car may be provided.

In the elevator remote monitoring system of the present invention, the reference sound generators on the monitoring center side and the monitoring terminal can be operated immediately after the direct-talk function is connected to perform gain adjustment.

[0026]

In the elevator remote monitoring system of the present invention, when the direct-speaking function is connected, the reference sound generator installed in the elevator car generates a reference sound at a constant sound pressure level on the monitoring terminal side. These signals are picked up by the intercom microphone to be used as a transmission signal, and the reference sound generator on the monitoring center side also generates a reference sound with a constant sound pressure level, which is sent to the monitoring terminal through the telephone line as a reception signal. Each of the reference transmission signal and the reference reception signal is converted into signal level digital output data by an A / D conversion circuit.

Then, the arithmetic circuit obtains an appropriate gain adjustment value for the output data of the above signal level by referring to the gain adjustment reference table, and the gain of the amplifier circuit is obtained based on the gain adjustment value obtained by this arithmetic circuit. Make adjustments.

In this way, by automatically adjusting the gain of the amplification circuit of the transmission / reception signal, the transmission / reception signal level is equalized, the transmission / reception switching circuit switches the transmission / reception signal according to the signal level, and the reception from the monitoring center, By transmitting to the monitoring center, the reliability and smoothness of the direct-speaking function are secured.

[0029]

Embodiments of the present invention will now be described in detail with reference to the drawings.

FIG. 2 shows the system configuration of an embodiment of the present invention, and like the general system configuration of FIG.
The elevator machine room installed in each elevator installation building is equipped with an elevator control device and a monitoring terminal 3. The monitoring terminal 3 is connected to an intercom 6 installed in the elevator car 5 by a tail cord 7. Further, the monitoring terminal 3 is connected to a monitoring center 9 of a maintenance company via a telephone line 8, and information communication can be performed mutually by connecting the line by dial operation.

As a feature of this embodiment, in order to cause the intercom 6 in the car 5 and the microphone of the intercom 6 to pick up the sound, the reference sound pressure is transmitted in response to the reference sound request signal 20 from the monitoring terminal 3. An announcement device 21 for outputting a level sound is provided, and a reference sound generating device 22 for generating a sound signal having a constant signal level to be transmitted by being mounted on the telephone line 8 is provided on the monitoring center 9 side.

FIG. 1 shows the internal configuration of the monitoring terminal 3, which is a telephone line processing unit 12 for connecting to a two-line public telephone line 8 and a calculation for amplifying a transmission signal and a reception signal. The amplifiers 13A to 13D, a transmission / reception switching circuit 14 that compares the signal levels of the reception voice and the transmission voice and switches the reception voice or the transmission voice by giving priority to the higher level.
An intercom connection circuit 15 and a CPU 23 that controls the operations of these circuits and performs necessary calculations are provided. Here, one of the operational amplifiers 13A to 13D, the operational amplifier 13A is provided with a gain adjusting circuit such as an electronic volume variable resistance value by an electric signal, and a gain adjusting signal from a gain adjusting CPU 23 described later. In response to 27, the gain is automatically adjusted.

The tail cord 7 is connected to the intercom connection circuit 15, and the tail cord 7 is connected to the elevator car 5.
It is connected to the intercom 6 installed inside. The intercom 6 includes a speaker 6A and a microphone 6B. The received voice is output from the speaker 6A, the transmitted voice is picked up by the microphone 6B, and is sent to the monitoring terminal 3.

The CPU 23 is provided with an A / D conversion circuit 24, and the signal level comparator 1 of the transmission / reception switching circuit 14 is provided.
Each of the voice transmission / reception signals input to 4C is input, and the volume data 24A obtained by converting the signal level of each of the transmission signals and the reception signals into a digital amount is input to the CPU 23. A volume data buffer 25 is also connected to the CPU 23 to store and store the volume data 24A described above. The volume data buffer 25 is an EEPROM or a battery backup RAM.
It is possible to avoid the influence of a momentary power failure.

Further, the CPU 23 is provided with a gain adjustment reference table 26, and the gain adjustment data indicating how much gain adjustment is necessary for the volume data 24A from the A / D conversion circuit 24 is stored in a table format. is doing. Therefore, for the volume data 24A, the operational amplifier 13A is referred to by referring to the data table of the gain adjustment table 26.
The gain adjustment signal 27A necessary for the above is provided.

In such a structure, the intercom 6
In order to directly talk between the monitoring center 9 and the monitoring center 9, the CPU 23 outputs a connection signal 23A indicating intercom selection, and the intercom connection circuit 15 receives the connection signal 23A and sets the monitoring terminal 3 to the tail code. It is electrically connected to the intercom 6 in the car 5 via 7. As a result, the communication line of the monitoring center 9-telephone line 8-monitoring terminal 3-tail code 7-intercom 6 is established.

Here, the telephone line 8 is a two-line type signal line, and the reception signal received from the monitoring center 9 and the transmission sent from the intercom 6 to the monitoring center 9 via the monitoring terminal 3 are transmitted. The signal and the signal are propagated in the same signal line in an overlapping manner. The telephone line processing unit 12 converts the 2-wire type signal into a 4-wire type signal, extracts the reception signal component from the duplicated transmission / reception signal, and puts it on the reception signal line 14A, or from the intercom 6 to the transmission signal line 14B. It has a function of transmitting the transmitted transmission signal to the telephone line 8.

Therefore, the reception signal from the monitoring center 9 is
After passing through the telephone line processing unit 12, operational amplifiers 13A, 13
The signal level is amplified to an appropriate volume range by B, and is output from the speaker 6A of the intercom 6 via the tail cord 7. Similarly, the transmission signal input from the intercom microphone 6B is also input to the monitoring terminal 3 via the tail cord 7, amplified to an appropriate signal level by the operational amplifiers 13C and 13D, and then transmitted through the telephone line processing unit 12. The call is sent to the line 8 so that the user can talk with the monitoring center 9.

Next, regarding the automatic gain adjustment operation of the operational amplifier 13A, the block diagrams of FIGS. 1 and 2 and the CPU 2 of FIG.
This will be described with reference to the flowchart showing the processing operation of No. 3.

Intercom connection signal 2 from CPU 23
The intercom 6 is connected to the monitoring terminal 3 by 3A, and at the same time, the reference sound vocalization request signal 20 is sent to the announcement device 21 in the car 5 (steps S1 and S2).

In response to this, a reference sound is output from the announcement device 21 in the car 5, the reference sound is picked up by the intercom microphone 6B, enters the monitoring terminal 3 through the tail cord 7, and the transmission signal line 14B. Is amplified by the operational amplifier 13D and input to the comparator 14C as a transmission comparison input. At this time, the transmission comparison input is also input to the A / D conversion circuit 24, the signal level of the voice integrated by the attached CR is converted into digital data, and is input to the CPU 23 as the transmission volume data 24A ( Step S
3). The CPU 23 stores the transmission volume data 24A in the volume data buffer 25 (step S4).

When the intercom is connected, the reference sound generator 22 also automatically transmits the reference sound to the monitoring terminal 3 on the monitoring center 9 side. Therefore, the telephone line processing unit 12 receives the reference sound signal at a signal level attenuated by the line loss of the telephone line 8, is amplified by the operational amplifier 13A through the reception signal line 14A, and is compared with the reception comparison input signal. Is input to the comparator 14C. At this time, it is appropriate to set the initial value of the gain of the operational amplifier 13A to about 18 dB which is the average line loss of the telephone line 8. This reference sound reception signal also has the same A / D as the reference sound transmission signal.
It is input to the conversion circuit 24.

The reception volume data 24A output from the A / D conversion circuit 24 is input to the CPU 23 (step S5), and the transmission volume data stored in the volume data buffer 22 is extracted. Are compared with each other (step S6), and a gain adjustment calculation is performed (steps S7 and S8). That is, the CPU 23 accesses the gain adjustment reference table 26 to input the received voice,
The gain correction value data 26A corresponding to the transmission sound volume data is provided, and the gain adjustment signal 27 corresponding to this is output to the operational amplifier 13A.

In response to this, the operational amplifier 13A changes the gain in the circuit as instructed so that the signal level of the reception voice signal passing therethrough becomes equal to the signal level of the transmission voice. Be improved.

Thus, the signal levels of the received voice signal and the transmitted voice signal input to the comparator 14C are corrected so as to be substantially equal to each other, the switching operation in the transmitted / received voice switching circuit 14 becomes smooth, and monitoring is performed. It is possible to maintain a good direct call between the center supervisor and the passenger in the car.

In the above embodiment, the announcement device normally provided in the elevator is used as the reference sound generator from the intercom 5, but the reason is as follows. That is, in recent elevators, floor guidance,
In many cases, an in-car announcement device that automatically performs full-packing guidance, etc. is equipped as standard. In this system, by using the announcement function as a reference sound generator, a request signal 21 for activating the announcement device from the CPU 23 is generated. This is because it is possible to easily obtain a voice by outputting and operating the announcement device in response to the output. In addition, the announcement device has an advantage that the voice of a person can be taken into the intercom as a reference voice (noise in the car + about 10 dB).

However, the present invention is not limited to this, and as means for obtaining the reference voice in the car, a system using a buzzer in the car, a system using a chime, or a voice synthesizer separately installed, It is possible to use a method of activating it, a method of making the intercom equipped with a holding tone and remotely activating the holding tone, and the like.

Further, the reference sound generator 22 installed in the monitoring center 9 preferably has the same sound quality and volume level as the voice of the receiver, but the gain adjustment reference table 26 of FIG. 1 is weighted from the beginning. By providing the corrected value data, it becomes possible to use even a reference sound having a different level and character from the human voice.

Further, in the above embodiment, when the intercom is connected, both the reception signal and the transmission signal are automatically adjusted in gain. However, in general, the reference sound input from the intercom in the same car is used. Since the signal level of the transmitter comparator input signal is considered to be almost the same when the line is connected, sampling of the transmitter signal is omitted every time the interphone is connected, and the volume data stored in the volume data buffer is omitted. It may be reused. In this case, the data in the volume buffer is updated, for example, at the time of regular inspection every other month. Since the loss of the signal level in the telephone line differs depending on the connection, it is necessary to sample the reference voice of the receiving system and adjust the gain every time the line is connected. Even so, sampling of the transmission system can be omitted, so that the operation can be performed faster than the gain adjustment operation wave.

FIG. 4 shows the internal structure of the monitoring terminal in another embodiment of the present invention. In this embodiment, when a plurality of elevators A, B, ... Are installed in one building, the gain of the direct talk function of the intercom in the elevator car of each elevator is automatically adjusted. It is a circuit configuration. In this embodiment, the intercom connection circuit 1 is connected to the intercoms 6, 6, ... Installed in each of the elevator cars for one CPU 23.
Are provided so that the connection signal 23A can be transmitted from the CPU 23 to any of the intercom connection circuits 15, 15 ,.
Then, a reference sound is generated from the reference sound generator to the intercom of the selectively connected car, the reference sound is picked up by the intercom, input to the monitoring terminal 3 as a transmission signal, and amplified by the operational amplifier 13D. The latter signal is the comparator 1
4C as well as the A / D conversion circuit 24 to obtain digital volume data and store it in the volume data buffer 25A, 25B, ... For each machine.

Since the other structure is the same as that of the first embodiment shown in FIG. 1, the description thereof will be omitted by giving the same numeral thereto.

In this embodiment, when a plurality of elevators are installed, individual differences such as intercoms and tail cords affect the signal level of the transmission sound signal depending on the selected machine, so that the operational amplifier 13A is controlled. By performing the gain adjustment for each machine, it becomes possible to communicate directly with the monitoring center at a good signal level using the intercom of any machine.

[0053]

As described above, according to the present invention, when the intercom is connected, the reference sound generator generates the reference sound, picks up the reference sound by the intercom, and supplies it to the comparison circuit of the monitoring terminal. Also transmits the reference tone generated by the reference tone generator from the reference tone generator through the telephone line, and automatically adjusts the gain of the amplification circuit of the transmission / reception signal individually according to the difference in these signal levels. Since the levels are equalized, the transmission / reception switching circuit switches the transmission / reception signals according to the signal level, and when receiving from the monitoring center or transmitting to the monitoring center, the signal level is too low or It is possible to secure the reliability and smoothness of the direct-speaking function without the reception signal or the transmission signal becoming inaudible due to excessive balance.

Further, in the present invention, in the case of a building in which a plurality of elevators are installed, a reference sound generating device is provided in the car for each elevator, and the signal level of the transmitted voice is received as a signal for receiving the sum for each of the elevators. Since the level is equalized, the reliability and smoothness of the direct-speaking function can be ensured in any elevator of any number.

Further, in the present invention, since the automatic gain adjustment is performed immediately after the intercom is connected to equalize the transmitted / received signals, the direct call can be always performed in a good state, and the direct call function can be provided. The reliability can be improved, and the service of passengers can be improved.

[Brief description of drawings]

FIG. 1 is a circuit block diagram of a monitoring terminal according to an embodiment of the present invention.

FIG. 2 is a block diagram showing the system configuration of an embodiment of the present invention.

FIG. 3 is a flowchart showing a processing procedure of a CPU in the above embodiment.

FIG. 4 is a circuit block diagram of a monitoring terminal according to another embodiment of the present invention.

FIG. 5 is a block diagram showing a system configuration of a conventional example.

FIG. 6 is a circuit block diagram of a conventional monitoring terminal.

[Explanation of symbols]

 2 Elevator control device 3 Monitoring terminal 5 Basket 6 Intercom 6A Speaker 6B Microphone 7 Tail code 8 Telephone line 9 Monitoring center 12 Telephone line processing unit 13A to 13D Operational amplifier 14 Transmission / reception switching circuit 14A Reception signal line 14B Transmission signal line 14C Comparator 15 Intercom connection circuit 16 CPU 21 Announcement device 22 Reference sound generator 23 CPU 24 A / D conversion circuit 25 Volume data 26 Gain adjustment reference table

Claims (3)

[Claims] 1. A remote elevator having a direct-speaking function for making a telephone call between an intercom in an elevator car and a monitoring center by using a monitoring terminal installed in elevator control devices scattered in each area. In the monitoring system, the monitoring center side is provided with a reference sound generating device for generating a reference sound of a certain level to be sent through the telephone line, and the monitoring terminal side is provided with a reception voice from the telephone line and a transmission to the telephone line. An amplifier circuit for amplifying a speech voice, a transmission / reception switching circuit that compares the signal levels of the reception voice and the transmission voice, and switches the reception voice or the transmission voice by giving priority to the higher level of the reception voice or the transmission voice, the reception voice and the transmission voice A / D conversion circuit for converting a signal level of voice into digital data, and a reference sound installed near the intercom to provide data to the A / D conversion circuit For the raw device, a gain adjustment reference table that compares the output data of the A / D conversion circuit with the corresponding gain adjustment data, and the output data of the A / D conversion circuit, the gain adjustment reference table is referred to. A remote monitoring system for an elevator, comprising: an arithmetic circuit that obtains an appropriate gain adjustment value by means of a gain adjustment circuit; and a gain adjustment circuit that adjusts the gain of the amplifier circuit based on the gain adjustment value obtained by the arithmetic circuit. 2. When a plurality of elevators are installed in one building, a reference sound generator is installed for each elevator car on the monitoring terminal side, and a gain adjustment value obtained by the arithmetic circuit. The remote monitoring system for an elevator according to claim 1, further comprising a storage circuit that stores the information for each elevator car. 3. The elevator remote according to claim 1, wherein the reference sound generators of the monitoring center side and the monitoring terminal are operated immediately after the direct talk function is connected to perform gain adjustment. Monitoring system.