DE4143560C2 - Monitoring system for programmable implanted transponder - Google Patents

Abstract

The monitoring system uses an interrogator transmitting an energising signal which is received by the transponder and used to provide a data signal incorporating temp. data and an identification code. The data signal is combined via phase shift keying with a carrier frequency which is higher than the frequency of the energising signal provided by the interrogator. Pref. the transponder has a programmable memory with a number of memory locations used to store data provided after mfr. of the transponder and accessed to provide the data signal.

Description

The present invention relates to a passive transponder which is used for Implantation in a host is suitable, according to the preamble of the claim 1. In particular, the present invention relates to a passive transponder, which after completion of manufacture is programmable and for monitoring your own properties of a host in which he is inserted is embedded, and in particular for the identification of a Tiers and its properties is used.

Transponder and measuring point scanner or scanner systems are known in the art. These systems include an interrogator or interrogator that sends signals transmits a passive transponder and from it receives. Such use is in an animal embedded transponder. The from U.S. Patent No. Known system 4,730,188 includes an antenna that a 400 kHz signal transmits which signal from that to the Animal embedded transponder is received, and one shared signal of 40 kHz and 50 kHz again. This signal is according to a combination of 40 kHz and 50 kHz portions of the transmitted signal encoded to a preprogrammed identification number speak which one in the passive transponder contained chip is stored. The identification Number is preprogrammed at the time of manufacture. This identification number allows identification of the animal in which the transponder is embedded. Of the Measuring point scanner then gives this identification number for editing in a micro-computer.

The known transponders are not completely satisfied because the amount of information provided by them can be transferred to those contained in them preprogrammed identification numbers is limited. Accordingly, the user must look at one  Use, for example animal identification, the preprogrammed identification number for identification Use the test animal. However, identifiers tion numbers usually as a short form for the description of data related to the animals. This requires the user to send their animal information to the predetermined transponder identification number adjusts what an increase in working time and effort pulls. In addition, the known system can not automa System status information, such as muscle voltage or temperature of the animal. Correspond Accordingly, the amount of information transmitted is very small.

Since the transponders share the received signals, the Transponder transmits a radio frequency received signal so that the divided signal has a frequency high enough to convey information. This high frequencies are approved by the FCC (Federal Communica tion commission) and therefore the performance quantity that can be fed to the transponder and thus the transmission distance is limited. Because the transmission antenna of the transponder works at 40 kHz, is the Transponder additionally background noise interference from Surveillance television screens or computer monitors subjected to the necessary and usual are present as they are in connection with the measured value microprocessors used. These monitors also work using a 40 kHz and 50 kHz radio frequency signal. Because these monitors have a higher power output than the antenna, interfere with the operation of the interrogator if the Interrogator near computers or various other monitors is used.

GB 2 163 324 A is a passive transponder according to the generic term of claim 1 known. The passive known from this publication The transponder is provided with a programmable memory device. The Programming the programmable memory device can as well also the data query communication between the interrogator and the Transponders are made contactless by means of inductive coupling. To a unintentional programming of the programmable memory device to be able to prevent is an increased in this known device Programming voltage of more than 40 V required.

DE 36 02 171 A1 describes a test device for an electromedical device known with the pre-programmable operating states in a test object can be generated in order to check a function on the part of the test object. The signal transmission between the device under test and the test device takes place via Signal lines instead.

It is the object of the present invention to use a passive transponder programmable memory device and increased security unintentionally overwriting the content of the programmable To provide storage device. According to the invention, this task solved by the passive transponder specified in claim 1.

The present invention provides a passive transponder that simultaneously scans an environmental condition and this information together with one of the
User programmable identification information is conveyed in a manner that is less susceptible to background noise.

In general, a passive transponder is provided according to the invention which identifies a condition to be scanned, for example the internal temperature or the like of an object, and simultaneously scans and transmits it. The transponder and / or interrogation signal from an interrogator ( 100 ) (hereinafter called the interrogator). The transponder is driven by the interro signal. A sensor circuit arranged in the transponder reads the condition to be scanned of an animal in which the transponder is embedded. A data sequencer receives the interrogation signal and enables the sensor circuit to output a signal representing the condition to be scanned. The data sequencer causes the signal representing the condition to be output via a transmission or transmission antenna contained in the transponder.

The transponder according to the invention comprises also a programmable memory circuit, that using one received from the transponder Signals with an identifier selected by the user tion code can be programmed. The data sequencer sequentially enables the sensor circuit output the temperature and the programmable Memory to issue an identification code. A Frequency generator and modulator is used to receive the condition representing the signal to be sampled and the Identification codes and for modulating the output Data on an output carrier signal in response to that Input signal provided. The output signal frequency is regardless of the input signal frequency that is less than Can be 10 kHz.

The invention is based on an embodiment example will be explained in more detail with reference to the drawing. It represents:

Fig. 1 is a block diagram of an interrogator according to the invention;

Fig. 2 is a block diagram of a passive transponder according to the invention;

FIGS. 3a and 3b are illustrations of the respective halves of the frequency generator and modulator according to the invention from Fig. 2;

Fig. 4 is a circuit diagram for a data sequencer according to the Invention;

Fig. 5 is a circuit diagram of a once programmable memory according to the invention;

Fig. 6 is a side view of a transponder according to the invention;

Fig. 7 is a plan view of a transponder according to the invention;

Fig. 8 is a sectional view taken along line 8-8 in Fig. 7; and

Fig. 9 is a sectional view taken along line 9-9 in Fig. 7.

In Figs. 1 and 2 are block diagrams of an exciter / receiver ( "interrogator") 100 and a IMPLAN-mountable passive transponder ( "transponders") 200 provides Darge. The interrogator 100 transmits an excitation signal to the transponder 200 . The excitation signal is received by the transponder 200 and feeds the transponder 200 . Once the transponder 200 has been excited, it is prompted to output a data signal. This data signal includes an introduction section, temperature data and an identification code. The data signal is a phase shift keyed or phase encrypted signal with a 455 kHz carrier frequency. The transmission is a continuous, cyclical data stream that contains the transponder identification and temperature information. This information is received by the interrogator 100 and is demodulated, translated and entered into a central computer for processing.

As will be explained in more detail below, the transponder 200 comprises a programmable memory 9 . The programmer 100 , which is coupled to a central computer, receives an identification code which is to be programmed into the transponder 200 . The interrogator 100 modulates the amplitude of the excitation signal to communicate with the transponder 200 . When the trans ponder 200 is in a programming mode, the once programmable memory 9 can be programmed by the interrogator 100 .

In an exemplary embodiment, the interrogator 100 communicates with the transponder 200 via inductive coupling, which is known in the art according to U.S. Patent No. 4,730,188, which patent is incorporated herein by reference as if it were incorporated in its entirety. The interrogation signal has a frequency of less than 10 kHz, more precisely 7109 Hz. The data stream returned by the trans ponder is output on a higher-frequency carrier signal of 455 kHz.

A more detailed description of the invention will now be given. A system will be described in which the transponder 200 has already been programmed and an identification code selected by the user is stored in the once programmable memory 9 . The interrogator 100 comprises a frequency generator 1 which outputs a 7109 Hz signal. A power amplifier 2 receives the output signal and causes the signal to flow through the primary coil of a transmitting antenna 3 , which generates an excitation field emanating from exciter 100 at a frequency of 7109 Hz.

With reference to FIG. 2, the internal construction of the Trans will be described ponders 200th A receiving antenna 4 installed in the transponder 200 receives the excitation signal from the interrogator 100 and inputs a 7109 Hz signal to a rectifier / regulator 5 . The rectifier / regulator 5 receives the AC signal from the receiving antenna and rectifies the signal. The unregulated voltage is then regulated to 3 volts in order to feed the digital circuit contained in the transponder 200 . In one embodiment, the rectifier / regulator 5 uses, for example, Schottky diodes to reduce the voltage drop. The rectifier / regulator 5 limits the voltage to protect the digital electronics. The rectified signal is then passed through a frequency recording, generator, and modulator device 6 , hereinafter referred to as frequency generator and modulator 6 , and input into a data sequencer 7 and a Manchester encoder and introduction generator 10 .

The data sequencer 7 receives as input signals the 7109 Hz signal, temperature data from a temperature / frequency converter 8 and the programmed identification data from a programmable memory 9 and controls the sequencing of the cyclically transmitted data stream, which includes the introduction, identification data and temperature data . The once programmable memory 9 stores the identification data therein. When the data sequencer 7 receives the 7109 Hz input signal, it first outputs an initiate enable signal which causes the Manchester encoder and initiator generator 10 to output an initiate data. It then outputs the identification data stored in the once programmable memory 9 . The data sequencer 7 accesses the address to be read from the memory 9 sequentially through the address bus 202 . This causes the memory 9 to output the data to the data sequencer 7 , which controls the data and outputs the identification data to the Manchester encoder and introduction generator 10 at an appropriate time.

In FIG. 4 is a circuit diagram of the Datensequenzie shown RERS. 7 The data sequencer 7 includes a counter 700 which receives the 7109 Hz signal, divides it by 16 and outputs a 444 Hz signal. The once programmable memory 9 outputs a programming lock signal, which indicates whether the memory has been programmed by the user with identification data. The programming lock signal has a value of 0 if the memory has already been programmed and a value of 1 if the memory has not yet been programmed. A first NAND gate 704 receives the 7109 Hz signal output by the frequency generator and modulator 6 as a first input signal and the inverted programming disable signal as a second input signal. A second NAND gate 706 receives the 444 Hz clock signal and the programming disable signal as input signals. The output signals of both NAND gates 704 , 706 are input to a third NAND gate 708 which controls each of the output signals and generates a clock signal with a value of either 444 HZ or 7109 Hz as an output signal.

A binary counter 710 receives the output signal of the NAND gate 708 and uses this signal as an internal clock signal. The binary counter 710 provides a data clock of 3555 Hz at its output Q1 when a signal of 7109 Hz is received. With this clock rate, the binary counter 710 also accesses the addresses in the programmable memory 9 sequentially via the address bus.

During the reading of data from the memory 9 , access to each memory causes identification data to be output by the memory 9 . This data is then input to a clock 718 which receives the 3555 Hz data clock output signal from the binary counter 710 as a clock input signal. This is used to synchronize the data output from the memory 9 with the transmission frequency, as represented by the data clock.

A NAND gate 714 and a NAND gate 716 are provided to control the transmission of the initiation, identification data and temperature data portions of the cyclically transmitted data stream. The NAND gate 714 receives the output of Q8 as one of its inputs and the output of Q9 as its other input and outputs the initiate enable signal. The NAND gate 716 receives the inverted output signal from Q8 and the output signal from Q9 so that the two NAND gates do not simultaneously enable the transfer of the respective data and outputs the temperature enable signal. In addition, a NAND gate 720 uses the initiate enable signal to control the temperature data generated by the temperature / frequency converter 8 so that the temperature waveform is blocked when the initiate enable has a low signal level.

During the read operation, the programming lock signal has a low signal level or value. Therefore, its inverted signal is high. Because an input to NAND gate 706 is 0 (the program lockout value), it continually produces a high output. On the other hand, the input signals of the NAND gate 704 are continued during the high signal and the oscillating waveform signal of the received 7109 Hz signal. Therefore, the output of NAND gate 708 will be a 7109 Hz clock signal. The binary counter 710 uses this signal and generates a data clock of 3555 Hz and a read rate of 3555 Hz.

For example, in one embodiment, if the output of Q9 is low, the initiation data and then the program identification data are output. When the value of Q9 goes high or rises to a high signal level, the initiation enable also rises to a high level and allows the temperature data to be transmitted through the NAND gate 720 . While Q9 is high, the EPROM of memory 9 continues to be sequenced. However, the identification data is not output by the Manchester encoder and the preface generator 10 .

In order to obtain the temperature data section of the output signal, a thermistor 19 in chip form is provided, which outputs a resistance value in response to temperature changes. The resistance value is input into the temperature / frequency converter 8 , which converts the resistance value into a frequency that is input into the data sequencer 7 . In one embodiment, the temperature / frequency converter 8 is formed, for example, by an RC oscillator, which is controlled by the resistance of the thermistor 19 . The frequency of the oscillator increases with temperature. The oscillator has a frequency of approximately 160 kHz at 36 ° C. The Datensequenzierer 7 controls this frequency and outputs the signal at an appropriate time to the Manchester encoder and initiation generator 10 off, thereby allowing the Manchester encoder and initiation generator 10 is possible to output a cyclically transmitted data stream, which the introduction, identification data and temperature / Frequency data includes.

The Manchester encoder and lead generator 10 receives the 7109 Hz signal and responds to the lead enable and temperature enable signals, data output and data clock signals generated by the data sequencer 7 . If the initiation enable signal generated by the data sequencer 7 is high, the Manchester encoder and initiation generator 10 encodes the data transmitted by the data sequencer 7 . The 7109 Hz clock is selected as the Manchester clock and the data output signal is always high and generates an output signal with twice the normal data clock frequency. This is a simple means of capturing the start of the cyclic data sequence. In a first step, the Manchester clock is mixed with the identification data in order to generate a Manchester-coded initiation and identification data signal. In a next step, when the temperature enable signal is high, the Manchester encoder and lead generator 10 replaces the Manchester encoded identification data with the temperature data and completes a cycle of data transmission. This data is transmitted to the frequency generator and modulator 6 at 3555 baud. Introduction, identification data and temperature data are generated in this order, for example. However, since the entire output signal is continuous and cyclical, the temperature data can be output first.

The frequency generator and modulator 6 receives both the data to be transmitted from the Manchester encoder and induction generator 10 and the received clock signal of 7109 Hz. The frequency generator and modulator 6 multiplies the input clock signal at 64 to a transmit carrier frequency of 455 kHz generate to output a 455 kHz carrier signal containing the data. This carrier signal is phase-shifted by 180 ° when the transmitted data change state to output a phase-encrypted signal.

In FIGS. 3a and 3b is a circuit diagram of the frequency generator and modulator is shown. The circuit shown in FIG. 3a operates digitally on the received 7109 Hz signal and provides an input signal for an analog section of the circuit shown in FIG. 3b. The frequency generator and modulator multiplies the frequency of the received clock signal (7109 Hz) to generate a 455 kHz carrier signal by comparing an internal, digitally controlled oscillator with the period of a cycle of the received clock signal.

An analog oscillator is provided with a capacitor 649 which is charged by a combination of voltage sources 630, 634, 638, 642 and 646 with values of i, 2i, 4i, 8i and 64i, respectively. The current is input to capacitor 649 for charging. Capacitor 649 is coupled to inverters 648 , 650 arranged in series. The output signal of the inverter 650 is input to a MOSFET transistor 652 for discharging the capacitor 649 . This ongoing charging and discharging provides an oscillator of a certain frequency. The rate of oscillation is based on the current sources such that the amount of charge stored in capacitor 649 as a function of the amount of current and then discharged through transistor 652 causes oscillations in the circuit and generates pulses of approximately 910 kHz. In one embodiment, capacitor 649 has a value of 10 pF, for example.

The 910 kHz signal is input to a circuit which divides it by 256 and includes a NAND gate 610 and two binary counters 608 , 612 . The 910 kHz signal is input to binary counter 608 and also to an input of NAND gate 610 . The second input of the NAND gate 610 is connected to the divided output Q3 of the binary counter 608 . The output of NAND gate 610 is input to binary counter 612 as a clock input so that the Q3 output is a signal with a frequency of approximately 3554.68 Hz.

At the same time, the received 7109 Hz signal is received by the frequency generator and modulator 6 and inverted by an inverter 602 . The inverted received signal is input to a flip-flop 604 as a clock input signal. The flip-flop 604 divides the signal by 2 so that its Q output signal is a signal with a frequency of approximately 3554.5 Hz. This signal is asynchronous with the circuit's 3554.68 Hz signal dividing by 256.

A NOR gate 618 , like the NAND gate 616, receives the two signals. A comparison between the two signals is made to determine which one occurs first and adjustments are made.

In order to prevent the arrival and departure times of the two signals at the NAND gate 616 from fluctuating relative to one another, a delay circuit is provided. The delay circuit includes flip-flop 606 , which provides an input to flip-flop 620 . The flip-flop 606 receives the 910 kHz signal as a clock input signal and provides a Q output signal for the flip-flop 620 , which is received at the D input of the flip-flop 620 . The flip-flop 620 in turn clocks this signal with the 910 kHz pulses of the oscillator clock generator formed around the capacitor 649 . This delays the output of flip-flop 620 by at least one cycle of the 910 kHz pulse signal.

A pair of NAND gates 624 , 626 are provided. The Q output of flip-flop 604 , which is the divided received signal at a frequency of 3554.5 Hz, is input to both NAND gates 624 , 626 , as is the delay Q output of flip-flop 620 . However, NAND gate 624 receives the inverted output of the circuit dividing the signal by 256 (the 3554.68 Hz signal), while NAND gate 626 receives the actual signal itself. The output signals of the NAND gates 624 , 626 are input to an up / down counter 628 . The QA-QD output signals of the up / down counter 628 control the amount of current flowing from each current source through switches 632 , 636 , 640 and 644 to the capacitor 649 .

The relative output signals of NAND gates 624 , 626 control an increase or decrease in the amount of current fed into capacitor 649 and thus influence the frequency of the pulses generated. This is a delayed function, so no matter which signal, the shared receive signal or the shared oscillator signal first assumes a high signal level, this signal is delayed before gates 624 , 626 can determine whether the up / down counter Counter 628 is to be increased or decreased. When flip-flop 604's Q output rises first, flip-flops 606 , 620 delay it. At the same time, when the Q3 output of binary counter 612 is low, the input of NAND gate 624 is high while the input of NAND gate 626 is low. The output of NAND gate 624 in this case causes an increment pulse to counter 628 . The counting of flip-flops 608 , 612 is controlled by flip-flop 614 , which receives the Q output of flip-flop 604 as its clear signal. The flip-flop 614, on the other hand, controls the resetting of the flip-flops 608 , 612 and thereby controls the output signal of the circuit dividing by 256. In addition, the clock input of flip-flop 614 is the output of AND gate 616 . When the Q3 output signal is 1 , the Q output signal of the flip-flop 614 goes high and causes the signal level of the Q3 output signal of the flip-flop 612 to decrease, which starts the whole process again. Counting can only occur when the Q output of flip-flop 604 is low.

If it is determined by NAND gates 624 , 626 that pulses are not output at 910 kHz, corrections are made by up / down counter 628 . The switches 632 , 636 , 640 , 644 are analog switches which allow the current from the respective current source 630 , 634 , 638 , 642 to be output to the capacitor 649 in order to charge it at a higher rate and thereby to increase the pulse frequency . When there is a need for an increased frequency, the number of switches 632 , 636 , etc. that are turned on to allow current to flow to capacitor 649 increases sequentially until the pulse frequency is sufficiently high.

A flip-flop 654 dividing by 2 receives the 910 kHz pulse as a clock signal and outputs a 455 kHz signal as a Q output signal. The 455 kHz signal is the carrier frequency for the data that are transmitted by the transponder 200 . An exclusive-OR gate 656 receives the 455 kHz signal and the data to be transmitted with introduction, identification data and temperature data as a second input signal. The exclusive-OR gate shifts the phase of the carrier signal by 180 ° in response to the data, so that the exclusive-OR gate 656 generates a phase-coded data output signal. This phase-encrypted signal is then transmitted to the interrogator 100 , where it is processed.

By multiplying the received clock by 64 receive a carrier frequency of 455 kHz. By digitally comparing the period of 64 cycles of internal, digitally controlled oscillator with the period a cycle of the received clock can be a very inaccurate frequency source with a very accurate frequency source can be synchronized to an exact carrier fre to generate a frequency at a much higher frequency, without imposing limits on the frequency values. How explained above, this is accomplished by determining becomes whether the received clock cycle is shorter or longer than which is 64 cycles of the oscillator. If the received Clock cycle is shorter, the oscillator frequency is too low and a boost pulse is generated and sent to one Output up / down counter of the power sources to the Capacitor controls. If the clock cycle received is longer, so the oscillator frequency is too high and a low The supply pulse is generated and sent to the up / down counter spent.  

The phase-encrypted data are output by the rectifier / regulator and a transmitting antenna 11 . A 455 kHz field is generated which is received by the receiving antenna 12 of the interrogator 100 .

The received signal is an optionally in an impedance buffer 13, the coil, the high impedance of the tuned receiver, which forms the receiver antenna 12, buffers so that the much lower impedance of the reception filter does not reduce the received signal strength. The impedance matched signal is input to a receive filter and gain circuit 14 . The receive filter amplification circuit 14 filters out unwanted signals and amplifies the received signal for further processing.

For example, in one embodiment, the receive filter gain circuit 14 uses a multipole ceramic bandpass filter with a passband bandwidth of ± 15 kHz and 60 dB attenuation in the stop band or blocked band to filter out unwanted signals. The signal is then amplified with a gain of 40 dB. The circuit is shielded and the power supply is isolated to prevent external electromagnetic interference from interfering with the received signal.

The amplified received signals are then input into a mixer and phase-locked loop circuit or PLL circuit 15 . The mixer mixes the received signal with a 410 kHz signal to produce a baseband received signal of 45 kHz. The PLL circuit generates a positive pulse with every phase shift of 180 ° of the received signal. These pulses are then entered into a micro-control unit 16 , where the received identification data are reconstructed and the part of the data stream from the transponder 200 , which forms the temperature-dependent frequency, is detected and analyzed.

The micro-control unit 16 reconstructs the identification data section of the received signal and the temperature information from the frequency pulses output by the temperature / frequency converter 8 . The micro-control unit 16 outputs data and suitable protocol signals, which may include a ready-to-send signal, which indicates that data is about to be sent. The transmitted data are then sent in serial form to an RS 232 interface 17 , which converts the data from digital levels to RS 232 levels. The converted information is then forwarded through a connection unit 18 to the central computer in which the data are processed.

By providing a passive transponder that is one Chip thermistor and a temperature / frequency converter contains, it becomes possible to increase the temperature of animals monitor in which the transponder has been implanted. The Temperature was used only as an example. By using data described above sequencers can have other system status properties, for example muscle tension, light level or others Fluid conditions, continuously monitored and communicated to you remote central computer are transmitted. In addition it will by providing a frequency multiplier Interrogation possible within the transponder signal less than 10 kHz, one not by the FCC (Federal Communications Comission) regulated frequency, too use. This makes it possible to send this Signals used to increase transmission power and thus increased transmission distances between the inductive to allow coupled interrogator and transponder. By using a frequency generator and modulator,  in which an internal digitally controlled period of time with is compared to a cycle of the received clock and being acted on can continue to be a very imprecise one Frequency source, namely the internally generated oscillator clock, with a very precise frequency source, the Received signal, to be synchronized to an accurate Frequency source at a much higher frequency generate that to transmit the more complex transmit data current of the transponder is suitable.

The programming of the transponder 200 will be described below with reference to FIGS. 4 and 5. The programmable memory 9 is an EPROM, the output of which is always enabled. Before it has been programmed, it is, as can be seen from FIG. 4, in a programming mode (the programming lock has a high signal level). This causes the data sequencer 7 to operate at an internal clock of 444 Hz. Before programming, each address of the once programmable memory 9 has a value of 1. The programming disable signal causes the data sequencer to operate with an internal clock of 444 Hz. This clock causes counter 710 to operate at a lower 444 Hz speed, causing data transmission to occur at a lower speed. Accordingly, the rate of the phase-coded data when the carrier signal is generated in the frequency modulator 6 is lower than that discussed above when an already programmed identification code is used. This is due to the lower data clock of the data sequencer 7 . This lower rate is 222 baud as opposed to 3555 baud as used during normal data transmission.

During programming, the interrogator 100 generally receives this different data rate and recognizes that the programmable memory 9 has not been programmed.

It then scans the identification section of the data signal and compares it address by address with the identification number to be programmed into the transponder 200 . If the values for the addresses do not match, the values are changed until the identification data stored in the programmable memory 9 correspond to those in the central computer.

In particular, interrogator 100, in a manner almost identical to that discussed above, except for a lower data rate, causes binary counter 710 to increment the address of the programmable memory being accessed. Initially, all 128 bits in the EPROM are set to 1. If the value of 1 for the address currently being accessed is incorrect, the central computer causes the microcontroller 16 to output a programming control signal to the power amplifier 2 . This causes the power amplifier 2 to output a high voltage signal via the transmitting antenna 3 to the receiving antenna 4 of the transponder 200 . This high voltage signal becomes a 12 volt signal after being processed by the rectifier / regulator 5 . This programming voltage is entered directly through the programming input of the once programmable memory 9 in order to change the value of the address of the EPROM which is currently being accessed from 1 to 0. This process is repeated for each address of the EPROM. If the value of that address is correctly set to 1, it is simply scanned, not processed and the binary counter proceeds to the next address. When each address has been read, the value of that address is output by the data output of the once programmable memory 9 and then processed by the data sequencer 7 as described above.

In programming mode, the programming lock signal is set to 1. Accordingly, the inputs of the NAND gates 706 and 704 are switched off from the reading mode described above. The input signals of the NAND gate 706 are 1 and the 444 Hz signal, so that the output signal of the NAND gate 706 is a waveform with a frequency of 444 Hz. In addition, the input signals of the NAND gate 704 are now 0 and a waveform, so that the output signal of the NAND gate 704 is always 1. Accordingly, the clock used by the binary counter 710 in programming mode is 444 Hz, which results in a data clock of 222 Hz. The operation of the enable gate and the temperature gate are identical to those described above.

When the last address of the once programmable memory 9 is programmed, the value is changed from 1 to 0. This causes the output programming lock signal to change the internal clock of the data sequencer 7 from the 444 Hz rate to the 7109 Hz rate. Correspondingly, the interrogator 100 determines on the basis of this new received phase-encrypted data rate during the next questioning by the interrogator 100 that it should not program the transponder 200 .

To generate the programming control signal, the power amplifier 2 is provided with a p-channel power MOSFET, which causes 24 volts to be applied to the upper voltage side of the exciter. This causes the generation of a much more powerful field of excitation. This high excitation field causes the currently accessed bit in the transponder 200 to be programmed to 0. On the receiving side, the rectifier / regulator 5 is provided with a Zener diode in order to limit the programming voltage to the 12 volts described above.

By providing programmable memory that issues a lock signal if each of its addresses once was programmed, and a data sequencer with a internal data clock that during programming  and works at different rates while reading, a programmable memory is provided, the one the inventive interrogator / trans allows programmers to use its ponder system own non-erasable identification codes for the monitored animals after production of the transponder to select. By using a lower frequency signals during programming than during Reception will also increase the efficiency of both Programming as well as the transmission of information improved.

In Figs. 6 to 9, an embodiment of the invention constructed in accordance with the transponder 200 is shown. The transponder 200 comprises a substrate or a carrier part 25 . The rectifier / regulator 5 is attached to the carrier part 25 together with a chip thermistor 19 . A chip 20 , which houses the structures of the frequency generator and modulator 6 , the data sequencer 7 , the temperature / frequency converter 8 , the programmable memory 9 and the Manchester encoder and introduction generator 10 , is also held on the carrier part 25 . The rectifier / regulator 5 , the chip 20 and the chip thermistor 19 are electrically coupled to one another by connecting tracks 27 arranged on the carrier part 25 .

The receiving and transmitting antennas 4 , 11 are formed around a ferrite rod 21 . The transmission antenna 11 is formed by winding a coil 31 around the ferrite rod 21 . The receiving antenna 4 is formed by a coil 34 wound around the ferrite rod. The coils 31 and 34 are coupled to the rectifier / regulator 5 via a bonding pad 24 .

In one embodiment, the transponder 200 is enclosed in a glass capsule 28 , for example. The capsule has a length of between 0.500 inch to 0.750 inch (between 1.27 cm and 1.91 cm and has a diameter of 0.080 inch and 0.100 inch (between 0.20 cm and 0.25 cm). The glass capsule can be covered with a protective layer of epoxy, be completely replaced or treated with protective epoxy to prevent migration in animals.

Interrogator 100 may be housed in two separate sections for ease of use. The power amplifier 2 , the impedance buffer 13 , the transmitting antenna 3 and the receiving antenna 12 can be accommodated in a sensor arrangement, as is known from US Pat. No. 4,526,177. The remaining structure of the exciter 100 can be housed in a separate housing. Such a separation of the structures reduces any interference from the micro-control unit 16 , the frequency generator 1 or the central computer onto the transmitting antenna 3 or the receiving antenna 12 .

By designing the frequency generator and modulator, the data sequencer, the memory, the temperature / Fre quenz converter and the Manchester encoder and Einlei tion generator on a single chip can efficient size and efficient cost can be obtained. By designing the entire transponder with one length less than 0.750 inch (1.91 cm) and a diameter of 0.100 inch (0.25 cm) or less will be the entire Arrangement implantable.

A passive transponder includes a receiving antenna for Receive an input signal. A frequency generator and -modulator receives the input signal and inputs data carrier signal with a frequency that is independent of is the frequency of the input signal. A programmable Memory and a thermistor are provided to help users  To provide identification data and temperature data, which are combined with the output signal.

Claims (5)

1. Passive transponder with

• - a receiving antenna device ( 4 ) for receiving an input signal,
• - A transmitting antenna device ( 11 ) for transmitting an output signal generated in response to the input signal and
• a memory device ( 9 ) programmable by a programming signal and having a plurality of memory addresses for storing data which was transmitted to the transponder ( 200 ) in the programming signal by a remotely located interrogation transmitter ( 100 ) after its manufacture.

wherein the output signal contains the data stored by the programmable memory device ( 9 ), characterized in that
that the programmable memory device ( 9 ), when each of the memory addresses has been accessed once during programming, outputs a blocking signal which influences the output signal to be sent to the interrogation transmitter ( 100 ) in order to allow reprogramming by the interrogation transmitter ( 100 ) prevent. 2. Passive transponder according to claim 1, characterized in that the output signal, depending on the blocking signal, either has a first frequency that enables the interrogator ( 100 ) to program the programmable memory device ( 9 ), or has a second frequency that allows programming of the programmable Storage device ( 9 ) prevented by the interrogator ( 100 ). 3. Passive transponder according to claim 1 or 2, characterized in that the transponder ( 200 ) has a data sequencing device ( 7 ) which receives the input signal and the blocking signal and generates a working clock signal and a further clock signal from the input signal, the frequency of which is less than the frequency of the working clock signal, and which accesses the programmable memory device ( 9 ) sequentially when the blocking signal is present on the basis of the working clock signal and when the blocking signal is not present on the basis of the further clock signal. 4. Passive transponder according to one of claims 1 to 3, characterized in that the programmable memory device ( 9 ) is programmed in response to the input signal.