FR2555843A1 - Terminal and installation for storing and consulting data by way of a single line - Google Patents

Abstract

The invention relates to data consultation. It refers to a data consultation installation in which a database 10 includes a first bank 14 containing digital signals and a second bank 16 containing analog data. All the data are transmitted by a single line 20. Before transmitting analog data for a specified period, the database transmits a switching command to a control unit 30 for the specified period. In this way the terminal 12 automatically toggles, for a requested period, from a first peripheral 24 to a second 28. Application to the consulting of multiple databases.

Description

 The present invention relates to a terminal and an installation for storing and consulting data requiring only a single signal transmission line, the line having a small bandwidth.

 Telephone lines of the switched network are commonly used for the transmission of telephone signals and for consulting databases, in particular using screen terminals, for example used in the "Videotex" system.

Such a terminal is sometimes called a "directory terminal" and allows information to be exchanged with a database, in digital format. This system does not allow the transmission of digital signals and analog signals representing sounds simultaneously.

 It is however often desirable that audio information be transmitted in the same communication as digital information. Thus, databases can include databases in digital form, associated with at least one database holding sound information which is associated with information from the digital data bar.

Installations are already known which allow the simultaneous transmission of digital signals and signals in another format or analog. For example, there are already known installations in which two lines are used, one for digital signals and the other for sound signals. There are also known installations in which a
.1 4 line k is used, but this line has a large weary nd so that separate channels can be assigned to digital signals on the one hand and to audio signals on the other hand, possibly with frequency transposition.

 However, there is no system allowing the transmission of digital signals and analog signals in an automatic manner, using a t-ule line with bandwidth tOlt, such as a switched public network or stéciaI-isdt low flow.

 The invention relates to a terminal and an installation allowing the exchange of information with two different formats by a single line. According to the invention, the installation is normally intended to operate with signals of a first form and, when signals in a second format have to be exchanged, control signals are transmitted so that they cause the switching of one device to another at the terminal, for a time initially determined according to the importance of the data to be transmitted in the second format, and a switching device ensures the connection of the second device, sensitive to signals in the second format, only during The device then automatically returns to the first format digital signal exchange configuration and can resume the same process.

More specifically, the invention relates to a terminal intended to receive signals by a single line and comprising at least two peripherals intended to work with different formats, the terminal comprising
a switching member normally having a first position in which it connects a first peripheral to the signal reception line and a second position in which it connects the second peripheral to the line, and
- a control member intended to receive directly or indirectly at least part of the signals when the switch is in its first position and to control the passage of the switch in its second position and its maintenance in this second position for a time which is determined by the signals he received.

 It is advantageous for the first peripheral to be of the screen-keyboard type, exchanging digital data. In a particularly advantageous embodiment, the first peripheral and the switching member are incorporated in the same device.

This advantageously comprises a switching circuit which is sensitive to the control signals and communicates the control member and the binder only when the digital signals indicate that analog signals, for example sound signals, will be transmitted.

 It is advantageous that the second device is a telephone, a speaker assembly associated with an amplifier and / or a microphone associated with an amplifier.

The inversion also relates to a data consultation installation, intended to ensure an exchange between a database and at least one terminal as described above, by transmission of signals by a single transmission line, this installation being such that
the database comprises a first database containing data of a first type, a second database containing data of a second type, associated with the data of the first type, and a transmission control member data signals in a first format corresponding to the data of the first type, control signals for nutation; duration control signals representative of a determined time, and data signals in a second format and corresponding data of the second type,
- the first device of the terminal is sensitive to data signals in the first format,
the second device of the terminal is sensitive to data signals in the second format, and
- the signals received by the terminal control member include at least the switching control signal and the duration control signals, the terminal control member holding the switching member in its second position for the determined time indicated by duration control signals.

 It is advantageous that the first format is a digital format and that the second format corresponds to analog data.

 The line is advantageously a telephone line of the public switched network.

 In one embodiment, the terminal has a unique modulator-demodulator intended to receive signals in the first position and to transmit them to the first peripheral and to the control member.

 In one embodiment, the data of the first type contained in the first database is digital data, and the data of the second type contained in the second database is analog data. In a variant, the second database contains data in digital form, and a converter transforms this digital data into analog data.

 In an advantageous embodiment, the terminal allows the transmission of signals in the second format to the corresponding database. When the sound signals are stored in digital form in the second data bank, the latter advantageously comprises an analog-digital converter.

Other characteristics and advantages of the invention will emerge more clearly from the description which follows, given with reference to the appended drawing in which
Figure 1 is a general block diagram showing a storage facility and ae data consultation according to the invention; and
FIG. 2 is a more detailed block diagram of an example of a data storage and consultation installation according to the invention.

 The installation schematically represented in FIG. 1 comprises a database 10 and terminals, one of which is identified by the reference 12. The database comprises two databases 14, 16, the bank 16 being considered for example as containing data representative of sound signals. A circuit 18 for controlling the database provides all the necessary management functions.

 The database 10 is connected to the terminal 12 by a line 20. Although a simple telephone line has been shown, it should be noted that the connection is generally carried out by means of one or more telephone exchanges. In this example, line 20 is considered to be a switched public service line with narrow bandwidth (300 - 3400 Hz) or low speed. In particular, these lines do not allow the parallel transmission of two types of data in different frequency bands, with suitable bit rates.

 The terminal 12 includes a switching unit 22 Oh which normally ensures the connection of the line 20 to a first peripheral 24, for example of the screen-keyboard type, by means of a modulator-demodulator 26. The second peripheral 28 is not connected to line 20 only when the switching member 22 (for example a relay) has been excited by a control member 30. In FIG. 1, this is shown connected to the modulator-demodulator 26 which already supplies 1 te The first peripheral 24. The second peripheral 28 can be a telephone set, but it is advantageously a loudspeaker associated with an amplifier, possibly provided with a microphone also connected to an amplifier, when the exchanges must be bidirectional. .

We now consider the operation of the circuit in Figure 1. The first device
which is connected to line 20 allows the subscriber with the terminal 12 to request, in the manner
@@@ tuell, the services he wants. In particular, it can @@ manage the display of various data pages.

the circuit 18 for controlling the database
ends that sound data, contained in the data bank 16, must be associated with digital data contained in the data bank 14, it transmits a specific command signal, in the format of the signals exchanged with the first peripheral 24, these signals reaching the control member 30.

This thus receives a switching command and a
@@@@ indicating the time during which it must maintain the switching member 22 in its other position. The control member 30 therefore excites the switching member 22, for a determined time. The peripheral 28 is then connected to the line 20 and the control member 18 can transmit the associated sound data, taken from the data bank 16, to the peripheral 28. Of course, the duration of the maintenance of the switching member 22 in the excited state i r.end of the importance of the sound data transmitted from the database 16, as determined by the control member 18.

 Thus, when the associated sound data has been transmitted, the device automatically returns to its initial position of exchange with the first device.

 In a variant also applicable to the embodiment of FIG. 2 described hereinafter in this memo, the switching member 22 is also in the position for connecting the second peripheral to line 20 when the terminal is not at all powered.

 One of the most advantageous configurations for the terminal is shown in the lower right part of FIG. 2, a little more in detail. This terminal is advantageous because it implements most of an existing peripheral, known as a "directory terminal" and comprising a screen keyboard, connected by a modulator-demodulator and already comprising a switching member.

 More specifically, this terminal comprises a first device 32, known as a "directory terminal" which includes a relay constituting a switching member 34, a modulator-demodulator 36, a decoder 38, and a screen keyboard 40. The terminal also includes a "peripheral socket" 42 which allows connection to the decoder 38 and to the excitation circuit of the relay 34. In this way, the control member can be connected to the device 32 by the socket 42.

The control member comprises a peripheral coupling circuit 44, a circuit 46 constituting a central processing unit, for example a micro processor, and memories 48. The diagram described so far therefore generally corresponds to that of Figure 1.

 The telephone handset 50 is connected to the contact of the relay 34 which is open when the terminal is energized.

This same contact is optionally connected to filters 52 allowing connection to a loudspeaker 54 via an amplifier 56 and to a microphone 58 via a preamplifier 60.

 FIG. 8 represents, in its upper left-hand part, a database of a particular type, since it contains sound data in digital form, this data being put in analog form before transmission by line 20.

 More specifically, the database proper, bearing the general reference 10, comprises, as in FIG. 1, a first database 62 containing digital data, and a second database 64 containing sound signals in digital form . The database control unit 66 is connected to a circuit 68 for switching between analog and digital modes.

In digital mode, the switching circuit 68 transmits the signals coming from the given dt bank 62 to a modulator-demodulator 70 then to a channel switch 72 which supplies the cauI, their line 74.

 When the data transmitted by the database 10 come from the database 64, that is to say represent, in digital form, analog signals, the switching circuit 68 supplies an input-output circuit 76 d a circuit controlled by a central processing unit 78, for example a microprocessor, associated with memories 80. An input-output circuit 82 is intended for the exchange of data while an input-output circuit 84 is intended for the exchange of control signals.

 The analog data put in digital form are transmitted by the circuit 82 to a digital-analog converter 86 which supplies a switching device 90 connected to the circuit 72. The analog data arriving via the line 20 are sent back to this switching device 90 and arrive to an analog-digital converter 88 which supplies the input-output circuit 82.

 The circuit which has just been described allows both the transmission of information from the database 64 to the terminal 12 as well as the reception of analog signals from the terminal 12 so that they can be stored in the database 64. Of course, when the installation is of the unidirectional type (simple consultation of data), certain circuits are superfluous (converter 88, switching member 90).

 Thus, according to the invention, the database which knows the importance of the analog signals to be transmitted, determines the duration during which the second peripheral must be brought online, and it then controls the switching by indicating the time L, <ndant which the second device must remain -n line. The control unit of the terminal receives this order as well as the prescribed duration and maintains the switching unit in the corresponding position.-Ii4ant the time which has been indicated to it. It then automatically returns the terminal to its initial position in which the first device is connected to the liyne.

 Of course, when the first peripheral, for example of the screen-keyboard type, comprises means for processing, ent of data and timing which are sufficient, it can perform the functions of the control member and in particular the timing.

Claims (9)

1. Terminal intended to receive signals by a single line (20) and comprising at least two periphery w .s (24, 28) intended to work with formats i turunts, characterized in that it comprises  - a switching member (22), normally having a first position in which it connects a first peripheral (24) to the line and a second position in which it connects the second peripheral (28) to the line, and  - a control member (30) intended to receive, directly or indirectly, at least part of the signals when the switching member (22) is.; :: tn. Its preitii; ru position, and to control the passage of the switching member (22) in its second position and then its maintenance in this second position for a time determined by the signals it has received. 2. Terminal according to claim 1, characterized in that the first peripheral (24) is of the screen-keyboard type, and the second peripheral (28) comprises at least one element chosen from the group which comprises a telephone set, a loudspeaker speaker with an amplifier, and a microphone with a preamplifier.  . T. rminal according to one of claims 1 @@ @, characterized in that the first peripheral  and the switching member (34) are incorporated in the same device (32). 4. Data consultation installation, intended to ensure the exchange between a database (10) and at least one terminal (12) according to any one of claims 1 to 3, by transmission of signals by a single line ( 20), characterized in that  the database (10) includes a first data bank (14) containing data of a first type, a second data bank (16) containing data of a second type and associated with data of the first type, and a controller (18) for transmitting the data signals in a first format corresponding to the data of the first type, switching control signals, duck signals of duration representative of a specified time, and signals data in the second format and corresponding to the data of the second type,  the first peripheral (24) of the terminal (12) is sensitive to data signals in the first format,  the second peripheral (30) of the terminal (12) is sensitive to data signals in the second format, and  - the signals received by the control member (30) of the terminal (12) include at least the switching control signals and the duration control signals, so that the control member (30) of the terminal (12 ) maintains the switching member (22) in its second position for the time indicated by the duration control signals. 5. Installation according to claim 4, characterized in that the first format is a digital format and the second format is an analog format. 6. Installation according to one of claims 4 and 5, characterized in that the single line is a telephone line of the switched network. 7. Installation according to any one of claims 4 to 6, characterized in that the terminal comprises a single modulator-demodulator intended to receive signals when the switching device (22) is in its first position and to transmit them to the first peripheral (24) and to the control member (30) of the terminal. 8. Installation according to any one of claims 4 to 7, characterized in that the terminal (12) comprises a source of signals in the second format, and the second database (16) is intended to receive signals from the terminals. 9. Installation according to any one of claims 4 to 8, characterized in that the data of the first type are digital data in a first format, and the data of the second type are analog data in the second format. 10. Installation according to any one of claims 4 to 8, characterized in that the data of the first type are digital data in the first format, and the data of the second type are digital data, the base comprising comprising a converter member ( 86) intended to transform the digital data of the second type into data in the second format.