Classifications

• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04B—TRANSMISSION
  • H04B5/00—Near-field transmission systems, e.g. inductive or capacitive transmission systems
  • H04B5/70—Near-field transmission systems, e.g. inductive or capacitive transmission systems specially adapted for specific purposes
• • G—PHYSICS
  • G06—COMPUTING OR CALCULATING; COUNTING
  • G06K—GRAPHICAL DATA READING; PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
  • G06K7/00—Methods or arrangements for sensing record carriers, e.g. for reading patterns
  • G06K7/08—Methods or arrangements for sensing record carriers, e.g. for reading patterns by means detecting the change of an electrostatic or magnetic field, e.g. by detecting change of capacitance between electrodes
  • G06K7/082—Methods or arrangements for sensing record carriers, e.g. for reading patterns by means detecting the change of an electrostatic or magnetic field, e.g. by detecting change of capacitance between electrodes using inductive or magnetic sensors
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04B—TRANSMISSION
  • H04B5/00—Near-field transmission systems, e.g. inductive or capacitive transmission systems
  • H04B5/20—Near-field transmission systems, e.g. inductive or capacitive transmission systems characterised by the transmission technique; characterised by the transmission medium
  • H04B5/24—Inductive coupling
  • H04B5/26—Inductive coupling using coils
  • H04B5/266—One coil at each side, e.g. with primary and secondary coils
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04B—TRANSMISSION
  • H04B5/00—Near-field transmission systems, e.g. inductive or capacitive transmission systems
  • H04B5/70—Near-field transmission systems, e.g. inductive or capacitive transmission systems specially adapted for specific purposes
  • H04B5/79—Near-field transmission systems, e.g. inductive or capacitive transmission systems specially adapted for specific purposes for data transfer in combination with power transfer

Definitions

• the present invention relates to a method for transferring energy from a main unit to a secondary unit and for bidirectional transfer of data between the main unit and the secondary unit and a system consisting of a main unit and a secondary unit for transmitting energy from the main unit to the secondary unit and for the bidirectional transmission of data between the main unit and the secondary unit.
• EP-A-288 791 already discloses a method and a system for transmitting energy from a main unit to a secondary unit and for bidirectional data transmission between these units.
• energy transfer takes place alternately from the main unit to the secondary unit or data transfer from one unit to the other unit.
• the transmission of energy and data takes place in a fixed cycle.
• Each cycle begins with an energy pulse of a predetermined duration, which is transmitted from the main unit to the secondary unit in order to ensure an energy supply to the secondary unit.
• a decay phase has elapsed after the energy pulse has been switched off, there is a switchover phase, during which the main electronics can switch the data direction between the main unit and the secondary unit for all further data cycles by transmitting a further energy pulse.
• EP-Al-02 87 175 discloses another method and system for transmitting energy from a main unit to a secondary unit and for bidirectional data transmission between these units. With this system, a simultaneous transmission of energy and data takes place.
• a carrier is amplitude-modulated, whereby, as will be explained later, eight bits (one byte) are modulated onto a high-frequency carrier for each data bit to be transmitted.
• a clock signal and a data signal are obtained from the received, modulated signal by means of a voltage divider in order to be able to distinguish a transmitted "0" with a first small amplitude from a transmitted "1" with a second, large amplitude. It is therefore necessary to adapt the transmission power of the main unit to the attenuation of the respective transmission link.
• the transmission of data from the secondary unit to the main unit takes place in that the secondary unit carries out a load change on the secondary coil with half the carrier frequency.
• the phase position of the switching of the load change on the secondary coil determines the state of the retransmitted bit.
• two start bits, one data bit with its complementary value, one clock bit with its complementary value and two stop bits are transmitted for the transmission of each data bit from the main unit. After these bits have been transmitted, the carrier is not modulated for a period of eight oscillations of the carrier. During this time, the data is retransmitted by sending back a data bit with the load change of the secondary coil described above.
• EP-A2-03 20 015 Another method and system for transmitting energy from a main unit to a secondary unit and for bidirectional data transmission between these units is known from EP-A2-03 20 015.
• the data transmission from the main unit to the secondary unit takes place by pulse duration modulation of a high-frequency supply voltage signal by means of three different pulse-pause ratios, which correspond to a transmitted "1", a transmitted "0 H” or the calling of a bit from the secondary unit
• Data is retransmitted from the secondary unit to the main unit by short-circuiting the secondary coil in the decay phase after the transmitted pulse from the main unit to the secondary unit, as a result of which the decay level of the primary coil voltage changes within the transmission cycle whether the value of the primary coil voltage of the return corresponds to a "1" or "0” from the slave unit to the unit.
• EP-A2-01 85 610 Another method and system for transmitting energy from a main unit to a secondary unit and for bidirectional data transmission between these units is known from EP-A2-01 85 610.
• the data transmission from the main unit to the secondary unit takes place by modulating the mutual phase position of two coherent supply voltage oscillations.
• the data transmission in the opposite direction takes place by changes in the load on the coils of the secondary unit. This means that a simultaneous directional data transfer possible.
• Two spatially separated coil pairs are required for the transmission of the two coherent signals.
• a network for data and energy transmission which has a network to which a plurality of units of the same structure are connected.
• the network is supplied with energy by a central supply device.
• the power supply unit is used solely for the energy supply with AC voltage.
• the data transmission between the individual units takes place in that each unit accesses the network in order to apply amplitude modulation to the AC voltage signal present there.
• a message transmission system is already known from EP-A2-01 95 626, in which messages modulated in the frequency keying method are transmitted from a secondary unit to a main unit.
• the present invention is based on the object of developing a method and system for transmitting energy from a main unit to a secondary unit and for bidirectional transmission of data between these units, that the secondary unit is simple and compact and that a secure transmission of the data is guaranteed in both data transmission directions.
• Fig. 2 is a block diagram of an embodiment of the slave unit
• FIG. 3 is a block diagram of an embodiment of the main unit.
• Fig. 4 is a timing diagram for explaining the transmission method according to the invention.
• the system for the transmission of data and energy designated in its entirety by reference number 1 in FIG. 1, comprises a main unit 2 and a secondary unit 3.
• the main unit 2 comprises a power supply unit 4 for supplying a main circuit device 5 which is connected to a first and a second coupling element Lla, L2a.
• the secondary unit 3 comprises a secondary circuit device 6, which is connected to a third and fourth coupling element L1b, L2b.
• Energy transmission from the main unit 2 to the secondary unit 3 takes place via the first and third coupling elements Lla, Llb.
• a bidirectional data transmission between the main unit 2 and the secondary unit 3 takes place via the second and fourth coupling elements L2a, L2b.
• any type of contact-free coupling elements are suitable for inductive or capacitive or optical coupling, both for data transmission and for energy transmission.
• the coupling elements Lla, Llb, L2a, L2b have the form of coils for generating an inductive coupling.
• the secondary unit 3 comprises a rectifier circuit 7, which converts the alternating supply signal received by the third coupling element L1b into a DC supply voltage V cc .
• the third coupling element L1b is also followed by a first signal shaping circuit 8, which converts the received, essentially sinusoidal signal into an essentially rectangular clock signal, which is supplied on the one hand to a reference counter 9 and on the other hand to a sequence control circuit 10.
• the fourth coupling element L2b is followed by a first transmission / reception switch 11, the switching state of which the sequence control circuit 10 is determined.
• the first transceiver switch 11 connects the fourth coupling element L2b to a second signal shaping circuit 12, which is connected on the input side to a data counter 13.
• a microprocessor 14 is connected both to the reference counter 9 and to the data counter 13 and is also connected to the sequence control circuit 10 for mutual data exchange.
• the microprocessor 14 has a reset logic circuit 15, which resets the microprocessor, for example, when the supply voltage V cc is initially applied and in the event of undesired program states occurring.
• a frequency shift keying circuit 16 for the retransmission of data from the secondary unit 3 to the main unit 2 is controlled by the microprocessor 14 for binary frequency shift keying, depending on the logical value of the bit to be retransmitted, and is on the output side with the first transmission / reception switch 11 in connection, which connects the frequency shift key 16 in its transmit position to the fourth coupling element L2b.
• the main unit 2 comprises a host computer 17 which is in communication with a second microprocessor 18.
• the main unit 2 further comprises an oscillator 19 which is connected to a power amplifier 20 which is connected on the output side to the first coupling element Lla for transmitting a high-frequency supply change signal to the slave unit 3.
• the output signal of the oscillator 19 becomes the second coupling element depending on a gate time or switch-on time defined by the second microprocessor 18 in the transmission position of a second transmission / reception switch 21 L2a supplied.
• a short or long gate time corresponds to the connection of the output signal of the oscillator 19 to the second coupling element L2a to the transmission of a first or second binary data value from the main unit 2 to the secondary unit 3.
• this connects the second coupling element L2a to a first phase-locked loop 22 and a second phase-locked loop 23, each of which is connected on the output side to the second microprocessor 18.
• the first phase-locked loop 22 responds to signals of the first frequency which the frequency shift keying circuit 16 of the secondary unit 3 generates, while the second phase-locked loop 23 responds to signals of the second frequency from the frequency shift keying circuit 16.
• the transmission method is explained in more detail below with reference to FIGS. 2 to 4.
• a clock signal is generated in the secondary unit 3 by the first signal shaping circuit 8, with which the reference counter 9 is clocked or incremented.
• the data counter 13 becomes corresponding to the Vibrations of the transmitted data signal are counted up, the sequence control circuit 10 having the reference counter 9 counted from the receipt of the data signal and thus from the start of the counting of the data counter 13.
• the reference counter 9 is used to define a time window with a time base defined by the clock signal.
• the microprocessor 14 reads out the data counter 13 at this point in time.
• the first microprocessor 14 switches over the first transmit / receive changeover switch 11 in order to initiate a retransmission of data from the secondary unit 3 to the main unit 2.
• the frequency shift keying circuit 16 generates in accordance with the data value to be transmitted now a transmission signal with one of two transmission frequencies.
• the second microprocessor 18 of the main unit has switched the second transmit / receive switch 21 after the end of the data transmission to the secondary unit 3, so that either the first or the second phase-rigid control circuit 22, 23 responds to the signal transmitted by the secondary unit 3 , which in turn is detected by the second microprocessor 18. This completes the data retransmission.
• more than one bit can of course be transmitted per transmission in the respective data direction, provided the data counter 13 has sufficient capacity and the transmission path is sufficiently secure.
• a corresponding multiple frequency shift keying with a suitable multiple phase-locked loop is required instead of a binary frequency shift keying.
• the method and system according to the invention enable a very low amount of circuitry on the side of the secondary unit 3, which, in addition to comparators and basic gates, is used almost exclusively with flip-flops for realizing counters and Dividers can be implemented. This makes it easy to design the slave unit as a user-specific integrated circuit.
• the main unit determines the start time of a cycle and the secondary unit determines the end of the same.
• both the main unit and the secondary unit can have the other unit wait before each data transmission in order to carry out certain time-critical tasks.
• the method according to the invention is further characterized by a high level of transmission security.
• a suitable choice of the time window an almost arbitrarily large transmission security can be achieved.
• the data counter content can be interpreted by suitable software in such a way that bits are transmitted in pairs, for example, or that the data counter content corresponds directly to one byte. Of course, however, this leads to a reduction in the achievable transmission security.
• the data transmission from the secondary unit to the main unit is also insensitive to interference due to the selected frequency shift keying modulation method.
• the slave unit can send back a bit after each bit received, the transmission of a byte in both data directions is possible almost simultaneously.

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• Engineering & Computer Science (AREA)
• Computer Networks & Wireless Communication (AREA)
• Signal Processing (AREA)
• Artificial Intelligence (AREA)
• Computer Vision & Pattern Recognition (AREA)
• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Theoretical Computer Science (AREA)
• Bidirectional Digital Transmission (AREA)
• Near-Field Transmission Systems (AREA)
• Selective Calling Equipment (AREA)
• Synchronisation In Digital Transmission Systems (AREA)

Priority Applications (3)

Applications Claiming Priority (2)

Publications (1)

Family

ID=6408272

Family Applications (1)

Country Status (7)

Cited By (2)

Families Citing this family (5)

Citations (5)

Family Cites Families (9)

• 1990
  • 1990-06-12 DE DE4018814A patent/DE4018814A1/de active Granted
• 1991
  • 1991-06-05 DE DE91910294T patent/DE59100782D1/de not_active Expired - Fee Related
  • 1991-06-05 JP JP3509507A patent/JPH05502147A/ja active Pending
  • 1991-06-05 WO PCT/DE1991/000480 patent/WO1991020135A1/de not_active Ceased
  • 1991-06-05 KR KR1019920703164A patent/KR960000146B1/ko not_active Expired - Lifetime
  • 1991-06-05 CA CA002084995A patent/CA2084995A1/en not_active Abandoned
  • 1991-06-05 AU AU79719/91A patent/AU640026B2/en not_active Ceased
  • 1991-06-05 EP EP19910910294 patent/EP0533709B1/de not_active Expired - Lifetime

Patent Citations (5)

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