Classifications

• • G—PHYSICS
  • G10—MUSICAL INSTRUMENTS; ACOUSTICS
  • G10H—ELECTROPHONIC MUSICAL INSTRUMENTS; INSTRUMENTS IN WHICH THE TONES ARE GENERATED BY ELECTROMECHANICAL MEANS OR ELECTRONIC GENERATORS, OR IN WHICH THE TONES ARE SYNTHESISED FROM A DATA STORE
  • G10H1/00—Details of electrophonic musical instruments
  • G10H1/0033—Recording/reproducing or transmission of music for electrophonic musical instruments
  • G10H1/0041—Recording/reproducing or transmission of music for electrophonic musical instruments in coded form
  • G10H1/0058—Transmission between separate instruments or between individual components of a musical system
  • G10H1/0066—Transmission between separate instruments or between individual components of a musical system using a MIDI interface
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
  • H04L25/00—Baseband systems
  • H04L25/02—Details ; arrangements for supplying electrical power along data transmission lines
  • H04L25/05—Electric or magnetic storage of signals before transmitting or retransmitting for changing the transmission rate
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
  • H04L25/00—Baseband systems
  • H04L25/38—Synchronous or start-stop systems, e.g. for Baudot code
  • H04L25/40—Transmitting circuits; Receiving circuits
  • H04L25/49—Transmitting circuits; Receiving circuits using code conversion at the transmitter; using predistortion; using insertion of idle bits for obtaining a desired frequency spectrum; using three or more amplitude levels ; Baseband coding techniques specific to data transmission systems
  • H04L25/4917—Transmitting circuits; Receiving circuits using code conversion at the transmitter; using predistortion; using insertion of idle bits for obtaining a desired frequency spectrum; using three or more amplitude levels ; Baseband coding techniques specific to data transmission systems using multilevel codes
  • H04L25/4923—Transmitting circuits; Receiving circuits using code conversion at the transmitter; using predistortion; using insertion of idle bits for obtaining a desired frequency spectrum; using three or more amplitude levels ; Baseband coding techniques specific to data transmission systems using multilevel codes using ternary codes

Definitions

• the present invention relates to a method for the transmission of information on an electrical medium. It is more particularly intended for the transmission of digital type information circulating in time series on the support. It has long been known to transmit information in time series on electrical media according to various methods. Methods and devices for transmitting information between musical instruments are known, for example, according to the MIDI (Musical Instrument Digital Interface) standard. Often, depending on the coding of information specific to the transmission method envisaged, it is not uncommon to be limited in the number of different coded messages that the transmission method is capable of circulating on the medium. In the case of the MIDI standard, for example, we very quickly come up against the imperative limitation to 16 addresses (also called channels) of different instruments that the system is capable of taking into account
• the invention aims to remedy the drawbacks of known methods by providing a method which makes it possible to increase the number of different messages that the system is capable of conveying while maintaining compatibility with existing systems.
• the invention relates to a method for transmitting a greater quantity of information between at least two devices according to which information elements which are successively circulated in time series on an electrical medium are circulated, these information elements consisting of a packet of binary transitions forming messages which include one or more data and / or addresses of the devices for which these data are intended, said method not increasing the number of transitions circulating on the medium and nevertheless making it possible to increase the number of different messages that the system is able to convey.
• the rest state of the binary transitions is used for possibly generate symmetrical transitions of the active state of the binary transitions with respect to their quiescent state so as to enrich the content of the message by replacing the two-state logic with at least one binary transition likely to be able to take the state of rest by a three-state logic.
• information we mean here any information whose semantic content can be coded.
• the devices constitute information transmitters, information receivers or combined information transmitters and receivers.
• the information elements follow one another in time series on the electrical support.
• succession in time series is meant to denote a transmission of each item of information in a time sequence one after the other, each element alone occupying all of the information capacity of the medium.
• electrical support is meant any means capable of conveying an electrical signal from one point to another. These supports will generally consist of one or more electrical conductors in the form of one or more wires insulated from each other and assembled in a cable provided at its ends with connectors.
• the coding of the information on the electrical support can be carried out in any known manner. It can, for example, be carried out in voltage, current, frequency, phase or any other means compatible with the support.
• the information elements consist of a set of binary and ternary transitions which follow one another over time.
• a binary transition is materialized by a sudden jump from the rest voltage to the working voltage (active state) or even from the working voltage to the rest voltage.
• binary and ternary transition sets also known as binary and ternary transition packets, form messages for devices connected to the electrical support. Each message contains one or more data intended for one or more devices). The message can also contain binary and ternary transitions reserved for the addresses of each of the devices. The purpose of these addresses is to identify a particular device and to allow the personalization of certain messages intended for this particular device.
• one or more symmetrical transitions are generated of the active state of the binary transitions with respect to their rest state.
• symmetrical transition is meant a symmetrical transition from the normal transition to the neutral state.
• the normal binary transition will be constituted by the engagement (or the cessation) of an electric current while the symmetrical transition will be constituted by the engagement (or the cessation) of a circulating current in the opposite direction on the same electrical conductor.
• the normal binary transition may consist of a positive step of electrical voltage and the symmetrical transition will consist of a step of negative value with respect to the same zero voltage level.
• Nsup [3 n . 2 , m'n) ] - 2 m
• n and m are whole numbers such that n is less than or equal to m.
• the three-state logic which replaces, according to the invention, the two-state logic is a logic in which each piece of information can take only one value selected from any of the three different values symbolized by -1, 0 and 1.
• a preferred variant of the method according to the invention consists in detecting the presence of the devices addressed. This detection can be done by any means adapted to the mode of coding of the information produced. If, for example, the coding is carried out with current, the voltage drop caused by this current can be detected in the resistors placed in series in the support circuit. This voltage drop can be used, for example, to generate a logical signal of acquiescence intended for the transmitting device.
• An advantageous coding mode of the binary information circulating on the medium is current coding.
• the two binary levels are materialized by the presence or absence of current. It does not matter whether binary level 1 is materialized by the absence or by the presence of current. In practice, an embodiment which has given good results is that in which the binary level 1 is materialized by the absence of current and the binary level 0, by its presence.
• the invention also relates to the use of the method for the communication of information relating to the operation of musical devices according to the MIDI communication standard.
• a current coding of 5 mA for binary level 0 and we interrupt this current for logic level 1.
• the basic frequency of such a MIDI communication system is 31.25 kbaud according to a protocol asynchronous, each message comprising a binary transition ("bit") of start of message ("start" bit in active state, ie state 0), 8 data bits and one end of message bit (“stop” bit in state of rest, i.e. state 1).
• the connectors placed at the ends of the information carrier cables are standard DIN 5-pin connectors (180 degrees). Pins numbered 4 and 5 are used to connect the current loop carrying the information, pin 2 is not connected (in the case of a "MIDI In” terminal) or is connected to the cable shield (in the case of "MIDI Out” or "MIDI Thru” terminals). Pins 1 and 3 are not connected.
• the second support is an electrical support parallel to the first support.
• the coding of the information on this second support can be carried out in a different manner from that used on the first support. It is possible, for example, to code the information on the first current support and on the second voltage support. However, in the majority of cases, it is preferred to carry out the coding of the information in the same manner on the two supports.
• a second current loop is connected to unused pins 1 and 3 of the same 5-pin DIN connector so as to produce a second information carrier.
• the invention also relates to an information communication system in accordance with the method according to the invention and to its use for the communication of information relating to the operation of musical devices according to the MIDI standard.
• the invention also relates to an information communication system, according to which the sending device maintains a reverse current on the support and that the receiving device modulates this reverse current in order to return information to the transmitter device and thus implement a bidirectional alternating communication system ("half-duplex" system)
• FIG. 1 represents a device according to the state of the art.
• the information circulating on the support enters the device through pins 4 and 5 of the standard connector DIN 2 marked IN connected to an optical coupler 6 via connections 4 and 5.
• the flow of binary transitions in series leaving the optical coupler 6 is then sent to a serial-parallel converter 8 which deserializes the information to develop the data words. These are sent via the connection 9 in the processing unit 10.
• the information generated by the processing unit 10 is sent via the connection 11 to be serialized in the parallel-serial converter 12, which is connected to the pin 5 of the DIN 14 connector marked OUT via connection 13.
• the DIN connector 3 marked THRU has its pin 5 connected to the signal leaving the optical coupler 6 via connection 15.
• Figure 2 shows two devices according to the prior art connected by a link conforming to the MIDI standard.
• the first device comprises a processing unit 10, a serial-parallel converter 8 and an optical coupler 6 connected to the DIN connector 2 (IN).
• An electric cable 16 connects the terminals 2, 4 and 5 of this connector to the terminals 2, 4 and 5 of the DIN 14 connector (OUT) of the second device.
• the OUT connector 14 is connected to a parallel-serial converter 17, itself connected to the processing unit 18.
• FIG. 3 diagramming said system.
• FIG. 3 gives a practical embodiment of the technique of generating ternary transitions.
• the processing unit 18 itself performs the parallel-serial conversion of the information without requiring the use of a separate parallel-to-serial converter.
• the serialized information is sent to output A of the processing unit 18 and enters the line amplifier 24, the output of which is connected by resistor 26 to the power supply and, via resistor 25, to the terminal 5 of the DIN 14 connector marked OUT.
• a second output B of the same processing unit 18 is connected to the terminal 4 of the connector 14 via the line amplifier 27 and the resistor 28, the output of the amplifier also being connected to the electrical supply via the resistor 29 .
• two optical couplers 6 and 21 are connected to the terminals 4 and 5 of the connector 2 marked IN via resistors 20 and 22.
• the outputs of these two optical couplers directly attack the processing unit 10 at the inputs marked C and D.
• the processing unit 18 is programmed so that, at any time, the signal on its output B is only emitted while the output A is in the quiescent state. Likewise, when output A emits a signal, output B is programmed to remain in the quiescent state.
• FIG. 4 gives a time diagram which illustrates the sending by the transmitter device of FIG. 3 of the message consisting of a "start" bit, followed by a normal bit, a symmetrical bit, a normal bit , a second symmetric bit and four normal bits and a "stop" bit.
• On the lower line one can follow the time evolution of the current circulating in the cable which connects the two devices.
• FIG. 5 represents a device according to the invention similar to that of the prior art shown diagrammatically in FIG. 1, except that it also has a second optical coupler 30 and two series-parallel 31 and parallel-series 32 converters intended to receive the second support. This second support is connected to pins 1 and 3 of the DIN connectors 2 (IN), 14 (OUT) and 3 (THRU).

Landscapes

• Engineering & Computer Science (AREA)
• Computer Networks & Wireless Communication (AREA)
• Signal Processing (AREA)
• Physics & Mathematics (AREA)
• Power Engineering (AREA)
• Spectroscopy & Molecular Physics (AREA)
• Acoustics & Sound (AREA)
• Multimedia (AREA)
• Electrophonic Musical Instruments (AREA)
• Dc Digital Transmission (AREA)
• Logic Circuits (AREA)

Applications Claiming Priority (3)

Publications (1)

Family

ID=3886876

Family Applications (1)

Country Status (6)

Families Citing this family (6)

Family Cites Families (9)

• 1993
  • 1993-03-02 BE BE9300195A patent/BE1006904A3/fr not_active IP Right Cessation
• 1994
  • 1994-02-28 JP JP6519399A patent/JPH08507664A/ja active Pending
  • 1994-02-28 EP EP94906800A patent/EP0694238A1/de not_active Withdrawn
  • 1994-02-28 US US08/522,309 patent/US5734682A/en not_active Expired - Fee Related
  • 1994-02-28 WO PCT/BE1994/000017 patent/WO1994021070A2/fr not_active Application Discontinuation
  • 1994-02-28 CA CA002157371A patent/CA2157371A1/fr not_active Abandoned

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events