Portable detecting plate which is programmable by fields.

Portable field programmable detector plate

p0001The invention relates to a portable field programmable detector plate according to the preamble of claim 1.

p0002At the present time, in which almost all production processes are automated, electronic identification technologies are in high demand, in which only one number is sent either (read only), or where variable data can even be included, which can be programmed over a distance (Read / Write). This portable data carrier or "detector plate" z. B. are planted in valuable horses under the skin to detect this always safe. Cows and pigs received an implant to control or to all data of animals to save from birth to the automatic feeding system.

p0003In production automation detector plate are used by so painting lines are fitted so that the vehicles have the appropriate color depending on the programming. A robot is about the handling systems a certain type of screws that were packed in the warehouse in a universal container and shipped by programming the detector plate at him.

p0004The prevalence of such techniques is strongly influenced by the price of the disk, because it is needed in large quantities.

p0005An attractive price, high life expectancy and a correspondingly small size is achieved mainly with batteryless detector plate. Many applications can be a "Read Only" system perform, but the possibility to change the data content of the detector, open now - and for the future - much greater prospects. This programmable variant, the invention is concerned. Basically all battery-free techniques is following in common: An RF transmitter emits an antenna, an electromagnetic field from. Upon entry into this field, the detector plate is energized and begins to send the stored data.

p0006A system clock for the electronics of the detector is often obtained by division from the frequency of the RF field. Thus, the data memory is read and the serial data stream provided by a special circuit a field synchronous attenuation of the RF field. This damping is coupled out at the receiver of the RF transmitter, amplified and digitally processed. In turn, it is possible to read / write systems, to modulate the RF transmitter, thus to transmit data to the detector plate over a distance.

p0007The option of being able to change the memory content in the detector plate by the packaging in a housing without contact, this technique opens much more areas of application than just the identification. There are only a few areas cited as cashless payments, tool management, conveyor systems, vehicle data and also personal data, for which a re-programmable detector plate can be used.

p0008The prior art of contactless programming techniques with detector plate is as follows. This can be programmed without contact, the detection wafer containing a plurality of coils, one for power transmission, the remaining coils are used for data transmission and synchronization.

p0009The spatial distances during programming will be a few millimeters. Mostly the detection wafer is therefore placed directly on the programmer. The modulation used is most FSK, as these can easily be decoded with a PLL circuit.

p0010In order to minimize the circuit scale, is synchronized with the prior art, the programming process by the field frequency.

p0011The known contactless programming techniques in detection wafers have several disadvantages. Thus, it is required a plurality of coils, for example two or three coils, to use the energy transfer for receiving, for synchronization and for sending. The production of low cost and especially of small detector plate is thereby impossible. But just the size is a critical feature in detection wafers for tool identification or veterinary implants, wherein the smallest possible size is desired.

p0012The use of more than one coil also often makes it necessary, the coils in their spatial arrangement in a very specific situation correctly to read / write unit to position. Due to this limitation, the systems with multiple coils for many applications are not suitable.

p0013Another disadvantage relates to the distance when programming. When Datendekodieren on the side of the detector analog Dekodiermethoden as FSK PLL demodulation be used with a large demand for electricity. This is a real field programming as a programming tool over a greater distance, impossible. The current required can be transmitted only through the smallest distances in the millimeter range. This limitation is especially in the CIM area very disadvantageous because there the exact positioning is often impossible. The battery-prone systems there used therefore are very much more expensive, but moves the read-write distance in a range between 5 - 10 cm. The aim is to realize such distances with battery-less systems.

p0014A further drawback finally relates to the field sync of the system clock. The use of the field frequency in order to generate the clock for the data rate thereof, is indeed obvious, and it saves an oscillator, however, it is not possible to program the detector plate via an AM modulation, since the field is switched off thereby and then no system clock is present.

p0015From US Patent No. 3,299,424 an identification device with a detector plate is known, the resonant circuit in the tuned state the RF field of the transmitter removes energy and thereby measurable feeds back to the RF transmitter.

p0016In DE 2748584 an identification device is described, which uses the characteristics of above-mentioned US-PS 3,299,424 and combines these features with the advantages of obtaining the supply voltage from the resonant circuit.

p0017The energy from an induction loop is finally also already known from DE-AS 1,219,990.

p0018All of the above three documents are not concerned with the possibility of the same resonant circuit which is needed for energy and data transmission, also for non-contact program or modify the data in the detector plate to use, especially in the context that only during the programming process very little energy is transmitted to the detector plate and just a conventional decoding circuit (PLL, FSK, etc.) as well as programming the memory requires a lot more energy than simply sending data.

p0019From the document WO-A-67 89 050 a transponder is known which is suitable for identification of objects and both the stored data can be transmitted to a base station and through the base station is programmable. The transponder comprises a coil provided with a tapped resonant circuit which is used both for energy transmission and for transmitting the data and programming of the transponder. When sending at least a portion of the coil is used. As modulation when sending and receiving FSK modulation is preferably used. The decoding in the transponder is effected by using this modulation with the aid of a PLL circuit. Furthermore, the transponder comprises a capacitor, which is used for energy supply in the transmission pauses.

p0020The invention is based on the object of a to create simple, space-saving and especially over large distances to be programmed detector plate.

p0021This object is carried out at the detector plate mentioned in the preamble of claim 1 by the features of the characterizing part of claim 1.

p0022In the invention, one and the same resonance circuit is affected by the Modulationseinkopplung of the read / write device so that the decoder PPM-coded switching signals is controlled in the detector plate, and thus, data is written in the memory of the detector via field modulation.

p0023In addition, the invention is only one coil for field programming for data transmission and for power supply to use, so that the detector plate can be made very small and inexpensive. In the aforementioned field programming commands and data are inventively mixed by AM modulation and transmitted with pulse pause modulation for detection wafer.

p0024The form of data transfer and an inventive purely digitally operating decoding circuit on the detector plate make zusamen with a backup capacitor inventive field programming also distances from 5 - 10 cm possible. The heart of the decoding circuit according to the invention, a plurality of counter and an oscillator which serves as feldunabhänigige time reference. Advantageous developments and embodiments of the invention result from the dependent claims.

p0025Based on the embodiment shown in the drawing the invention is explained in more detail below:

p0026Show it:<dl id="dl0001"><dt>Fig. 1</dt><dd>A schematic representation of the combination of read / write device / detector plate,</dd><dt>FIG. 2</dt><dd>the block diagram of a detector plate,</dd><dt>Fig. 3</dt><dd>a diagram of the decoding logic in the inventive detector plate,</dd><dt>Fig. 4</dt><dd>a data telegram from the detector plate to read / write device, and</dd><dt>Fig. 5</dt><dd>Data telegrams from the read / write device for detection wafer.</dd></dl>

p0027The illustrated in Fig. 1 the read-write device comprises a RF transmitter having a modulator and a data receiver with a demodulator. The RF transmitter generates a quartz-stabilized frequency, which is conducted in a resonant circuit RK 1 as an antenna order to build a RF field. The modulator controls the RF field by Feldbedämpfung so that an AM pulse pause modulation arises, which is used for data transmission to the detector plate.

p0028On the same resonant circuit RK 1, a data receiver is connected, which demodulates the Feldbedämpfung of the detector and then processes them to detect z. B. the number of the detector.

p0029while four different things are transmitted over the same RF field: energy, commands and data to the detection wafer and data read-write device from the detector plate.

p0030Fig. Figure 2 shows a detector plate, in which a resonant circuit RC is composed of a coil L 1 and a capacitor C 1, the resonance frequency corresponds to the frequency of a pressure prevailing in an electromagnetic field detection zone.

p0031If the detection wafer is brought into the detection zone, the resonant circuit RK by Detektierfeld is caused to oscillate. This creates an alternating voltage across the LC circuit, of which in this example, the coil L 1 and the capacitor C 1 are connected in parallel.

p0032The AC voltage passes through a rectifier, which is symbolically represented here with D 1, the chip E. On the chip E are an oscillator with a counter controls the code generator and the decoder and a memory in which a code is. This memory communicates with the code generator and the decoder.

p0033In the readout process which is initiated in the RF field after the immersion of the detector, the code generator processes the data contained in the memory and sends these data modulated at the read-write device by a switching member SG the resonant circuit RK tune.

p0034When programming operation rated the decoder together with counters and the oscillator, the received modulation of the read-write device and progammiert the data in the memory. The "S" in the memory can be programmed from manipulation reasons there only once.

p0035A capacitor C 2 is provided as a buffer capacitor to enable programming pulses to the memory even if no constant power supply by the modulated RF field is possible.

p0036In addition, the capacitor C 2 is required to ensure the pulse pauses in the function of the decoder to the counter and the oscillator and the function of the whole chip to maintain, since the field is temporarily switched off during the programming operation.

p0037The following is a functional description of the detector will be given with reference to FIG. 3, initially the functional sequence when reading of the detector will be explained. If the detector plate in an RF field with the Feldfreque passes nz F2, the energy supply by means of the resonant circuit RK, the rectifier D 1 and the backup capacitor C 2 takes place The oscillator provides the field-frequency-independent system clock F1. The applied field frequency F2 holds counter 1 and the flip-flop FF1 is in the reset state. The address generator generates by means of two binary counters (counters 1 and 2), the data addresses and causes the read out of the memory. A Work In address generator shift register accepts the implementation of the parallel data into a serial data stream.

p0038The code generator has to implement the task of the serial data stream in known serial data formats (FSK, BIPHASE) (see Fig. 4). In addition, the code generator to the switching element SG causes the data transmission by a field modulation.

p0039The functional sequence for field programming of the detector is as follows: The basis for the field programming of the detector of the support capacitor C 2 and the oscillator, which together ensure that the system clock F1 and the supply voltage of the detector for the AM and data-related disconnection of the RF -field remains. The programming operation begins when the RF field for a bit longer than the time T 1 is turned off (see. Fig. 5 / E).

p0040Since the counter is 1 no longer resets (and the system clock from the oscillator continues to run), its output Q 6 goes to T 1 on High, sets the flip-flop FF4 and stops itself. The set flip-flop FF4 now opens with the CS signal the command decoder. The high level of the signal is also FF1 at the D input of the flip-flops.

p0041After the time T 1, the RF field is switched on again and the counter 1 resets characterized. In addition, the capacitor C 2 is now naturally recharged.

p0042If now the RF field is switched off again, the flip-flop sets the first high-level of the output Q 2 of counter 1 FF1 (without signal CS, the flip-flop FF1 is not set). This high level reached at the output of flip-flop FF1 as a DATA signal to the command decoder and also sets the flip-flop FF2. This flip-flop is in turn releases the counter. 2 and 3 The counter 2 generates with the aid of the flip-flop FF3 after the time T 2 (see Fig. 5 / G) the clock signal for the command decoder. Depending on whether the RF field for the duration T 3 and T 4 (see Fig. 5 / F) is turned off, assumes the command decoder with the CLOCK signal, a DATA-H or DATA-L (ppm).

p0043The CLOCK signal also resets the flip-flop FF2, the counter 2 and the flip-flop FF3. The first data to be transmitted to commands to the command decoder (see Figure 5 / A.), Which sets the detector plate on the basis of these commands in the following four states:<ul><li>1. Programming memory: After recognizing the programming command, the command decoder sets the flip-flop FF6 and are using the flip-flop FF7 the counter 4 free. In addition, a multiplexer is switched to the flip-flop FF6, which directs all subsequently transmitted signals CS, DATA and CLOCK to the memory. Thus, the transferred data is written into the memory. Each transmitted DATA signal causes a reset for the counters 3 and 4, so that extends the duration of the CS signal (counter 3) and the programming (multiplexer switching counter 4) until no further data is transmitted. The detector plate is then immediately returns to the read mode.</li><li>2. Stop reading: After detection of the stop command, the command decoder via the line L and over the code generator stops the modulation of the RF field. The stop command enables the read-write device, disable a detector plate immediately after the detection of the RF field and to recognize in this way even more passing into the RF field detector plate.</li><li>3. Read memory: The readout command is the inverse of the stop command (via the line L is the code generator enabled). The read command is transmitted when a previously abgeschaltetes detector plate to be reactivated. Depending on the area of ​​the detector further commands are of course possible.</li><li>4. Set the operating mode: The detector plate is also a mode register, which is automatically loaded upon entry of the detector in the RF field with the data bits of the first memory address. These data bits following operating modes are set: Baud rate, single-phase modulation, two-phase modulation, field-synchronous and feldasynchrone data transmission, binary format, Biphaseformat, FSK format, FSK frequencies, memory size, read-write mode, read-only mode, etc. Since the memory content changed by the RF field (programmed) can be, it is possible at any time to reprogram the detection wafer from one mode to another mode.</li></ul>

p0044Fig. 4 shows a data telegram which is transmitted from the detector plate to the write-read apparatus. The message begins with a header, which is required for the detection of the detector, followed by the actual data, and a CRC check at the end.

p0045For the code structure of various self-clocking codes can be dialed as Biphase, Manchester, etc. The transmission of 0 and 1 - bits can be accomplished by damping the field A or by superimposing two frequencies B or by other types of modulation.

p0046In Fig. 5 seven data telegrams AG are represented by the read-write device for detection wafer.

Data message A:

p0047To program the detector plate, a command header is sent first, followed by a command instruction and the actual data. Some of the possible commands are:<ul><li>1. Write data</li><li>2. Read data</li><li>3. Start data transfer</li><li>4. Stop data transmission.</li></ul>

Data telegram B:

p0048The modulator of the read-write device damped while the pitch of the RF generator and generates the pulse pause signal PPM in the resonant circuit RK. 1

Data String C:

p0049This modulated RF field is now sent through the communications link to the detector plate.

Data telegram D:

p0050The data transmitted from the resonant circuit RK 1 cause temporally proportional data on resonant circuit RK or at the input of the decoder, etc. formed by the above-mentioned counter, flip-flops from the detector plate.

Data telegram E:

p0051After the time T 1, the decoder delivers the command detection signal (CS signal).

Data telegrams F / G:

p0052Due to the transmitted PPM signals T 3 and T 4 of the decoder generates by command detection with the counter T 2 Clock and data for performing the various commands. In this manner, commands (as in A) and data from the write-read system are transmitted to the detector plate.