CN116796780A

CN116796780A - Method for automatically sending sensor data code stream by RFID tag

Info

Publication number: CN116796780A
Application number: CN202311083858.4A
Authority: CN
Inventors: 吴边
Original assignee: Excelio Technology Shenzhen Co Ltd
Current assignee: Excelio Technology Shenzhen Co Ltd
Priority date: 2023-08-28
Filing date: 2023-08-28
Publication date: 2023-09-22
Anticipated expiration: 2043-08-28
Also published as: CN116796780B

Abstract

The invention provides a method for automatically sending sensor data code stream by an RFID tag, which provides a logic control mechanism for integrating a temperature and pulse sensor to a passive radio frequency identification tag chip, wherein the logic control mechanism can be implemented in the form of a flexibly configurable finite state machine or in the form of simple operation steps or processes which are executed in sequence, and the temperature and pulse sensing information, pulse measurement data and calibration parameter data related to the sensor are circularly and repeatedly sent to a data reading device by using a mode of uplink transmission of the radio frequency identification tag, so that the communication reliability of the passive wireless temperature and pulse sensor is improved, and smooth user experience is obtained.

Description

Method for automatically sending sensor data code stream by RFID tag

Technical Field

The invention belongs to the technical field of radio frequency identification (Radio Frequency Identification, RFID), and particularly relates to a method for integrating a temperature sensor, a pulse sensor or other sensors in a passive and passive radio frequency identification tag and automatically and circularly sending a sensor data code stream to data reading equipment by utilizing the RFID tag so as to improve the communication reliability of the sensor.

Background

In the application field of the Internet of things of everything at present, as a network node in a wireless sensor network, a wireless sensor tag combines information sensing and measuring functions with radio frequency data transmission functions under the support of two technologies of a radio frequency identification tag technology and an intelligent sensor technology, and an countless intelligent application of the wireless sensor tag is started in daily life and industrial ecology of people. On one hand, as a core technology of a foundation in the wireless transmission technology of the internet of things, a radio frequency identification tag (RFID) technology is widely applied to various aspects of social life, such as application of logistics tracking, storage checking, smart card payment, access control and the like, and a matched data acquisition system and a mobile terminal are ubiquitous. Different from other wireless transmission technologies, the most outstanding passive characteristic of the radio frequency identification tag technology is that a battery is not needed when the tag works, and the passive radio frequency identification tag technology can convert energy from surrounding electromagnetic fields into electric energy and supply the electric energy to work of circuits inside the radio frequency identification chip, so that the radio frequency identification tag technology is very suitable for large-scale and low-cost deployment in the technical field of the Internet of things, and has very outstanding commercial value. On the other hand, the intelligent sensor technology can convert perceived and measured physical quantities in the surrounding environment into binary digital codes for digital storage and transmission, so that people can accurately display and further process perceived and measured environmental information by using digital equipment. The passive and passive radio frequency identification sensor tag technology is an innovative technological breakthrough in the field of the Internet of things, has huge application prospect, and is the first choice technology for widely implementing the wireless sensor network.

In particular, in the fields of livestock breeding, pet health care and biological and medical experiments, animal identification taking international standard ISO 11784/11785 as industry specification has application requirements of higher-level organism sign monitoring on basic application examples of identity identification; as one of the most important indicators of vital signs, the measurement of the body temperature of an animal needs to be accurate to an accuracy of less than +/-0.1 degrees celsius and collected along with identity information into a data system. Unlike smart card tags in other fields or traditional ear tag tags in the field of animal identification, the main carrier for this application is a glass tube tag made of bioglass material. A passive radio frequency identification chip with the resonance frequency of 134.25 kHz is arranged in the glass tube tag and is implanted into an animal body, and people can read the identity information of the animal through an external scanning and reading device. After the semiconductor temperature sensor is integrated into the 134.25 kHz low frequency animal identification tag chip, the voltage signal, which is in direct proportion to the in vivo ambient temperature, is sampled and quantized to binary values with a certain (typically 8-to 24-bit) accuracy, and transmitted in the form of a modulated coded digital code stream in a radio frequency communication manner, and finally read by the data acquisition system. Furthermore, an ECG electrode plate is encapsulated on the outer wall of a tag glass tube implanted in a living body, a circuit inside the glass tube is connected with the tag glass tube by a wire, a heartbeat pulse signal of the living body can be conducted into a chip inside the glass tube through the electrode, collected and amplified by an on-chip integrated amplifier, and quantized into a binary digital signal with pulse measurement information, typically 8-bit to 24-bit precision through signal processing of a Time-to-Digital Converter, abbreviated as TDC), and finally transmitted in a form of modulated and coded digital code stream in a radio frequency communication mode and read by a data collection system.

Combining passive rfid tags with semiconductor sensors into a single chip of passive, passive wireless sensor presents a number of technical challenges. First is a challenge in low power design. As the name implies, the passive radio frequency identification tag is a tag without an external power supply or battery power supply, and the electric energy required by the tag during operation is derived from an alternating magnetic field obtained by induction of a tag coil and a surrounding magnetic field, and the alternating magnetic field is converted into a direct current power supply required by the operation of the whole tag circuit through an alternating-to-direct current rectifying and voltage stabilizing circuit in the tag chip; according to the current required by the operation of the tag circuit and the time required to continuously operate under the condition that the surrounding electromagnetic field is completely turned off, the chip can be externally connected or not externally connected with an energy storage capacitor. When an external energy storage capacitor is connected, the energy storage capacitor stores charges when a surrounding magnetic field is coupled into an inductance coil connected with the chip; when the surrounding magnetic field is completely turned off, the electric charge stored on the energy storage capacitor is released to the tag circuit, and the tag circuit plays a role of a power supply. The power supply mode of magnetic field induction and rectification and voltage stabilization determines that the electric energy consumed by the whole radio frequency identification tag chip circuit during working must be minimized, otherwise, the operations of radio frequency identification downlink demodulation, uplink response and the like meeting the requirements of a certain communication distance cannot be completed. Under this limitation, the sensor must first measure the physical quantity to be measured accurately, and further, the analog physical quantity obtained by the measurement must be converted into a digital code suitable for data communication and transmission, i.e., a/D conversion, and it is obvious that both processes must reach the minimum power consumption limit.

As is well known, the physical quantity measured by the sensor belongs to a weak signal, and the processing and amplification of the weak signal need to overcome the influence of device noise (such as power supply level, noise on a ground line and the like), common mode signal change (caused by a changed direct current working point) and differential mode mismatch deviation, so that the processing and amplification of the weak signal need to consume larger power consumption in the traditional circuit technology; on the other hand, to track the change of the sensor signal requires the whole signal processing system to have a relatively large signal processing bandwidth to obtain a relatively fast response speed, and a large bandwidth also means a relatively large system power consumption. The conversion process of sampling and quantizing the analog signal to the digital signal also involves consideration of signal-to-noise ratio, common mode rejection ratio, power supply voltage rejection ratio and signal bandwidth; based on the same principle and inference, the accurate A/D conversion also needs to consume larger current and system power consumption to meet the key performance indexes of the mismatch and the random mismatch of the comparator system in the A/D conversion and the linearity requirement taking differential nonlinearity and integral nonlinearity as indexes in the dynamic range of the input signal. This is also a dilemma faced by low power designs known in the industry. Such difficulties face significant technical challenges in integrating the sensor with passive, passive radio frequency identification tags.

Further, the intelligent temperature and pulse sensor inevitably involves the operation of multiplication and division of voltage and current representing the measured physical quantity of temperature and pulse, so as to achieve the functions of mathematical scaling and linear mapping, and the necessary consistency calibration operation related to the sensor is added, and floating point number operation becomes a necessary condition for acquiring intelligent temperature and pulse information. The limitation of low power consumption makes it impossible for the passive rfid tag integrated with the temperature sensor and the pulse sensor to implement a microcontroller with floating point number calculation capability, i.e. MCU (Micro Controller Unit) unit, on-chip; meanwhile, if the floating point number operation is performed by using limited special hardware on the passive radio frequency identification tag, namely a mode commonly known as ASIC (Application Specific Integrated Circuits), the floating point number operation is very high in power consumption and chip area, and is not a preferred method. Thus, a series of floating point arithmetic operations required by the intelligent temperature sensor and the intelligent pulse sensor cannot be performed on the passive radio frequency tag, and the temperature and pulse measurement information required by calculation and the indispensable consistency calibration parameters related to the sensor have to be sent to one end of the RFID card reader device, and the MCU unit on the RFID card reader device is utilized for floating point operation, so that the calibrated real temperature and pulse data are obtained. Under this application limitation, the role played by passive rfid tags is limited to passive temperature and pulse measurement as well as wireless data transmission.

Secondly, the challenge of the application mode is focused on the technical challenges faced by the downlink communication mode and the uplink communication mode. When a temperature sensor for an application targeting animal body temperature and pulse measurement is integrated into an RFID chip conforming to the international low frequency animal identification standard ISO11784/11785, the transmission technique of its temperature data, pulse data and related sensor calibration parameters faces the selection of whether to use a downstream communication mode or an upstream communication mode. The downlink command mode, also called "card reader talk-ahead" mode, or RTF mode (Reader Talks First), is an operation mode in which the card reader sends out a command, the low frequency identification tag receives the command and then completes the action required by the card reader, for example, after comparing the ID numbers, the card reader enters a selected state, or a password login state, or performs the operation of reading and writing the memory meeting the command requirements, and sends out a feedback signal to the card reader device. The so-called upstream data transfer mode, also called the "Tag talk-ahead" mode, or TTF mode (Tag talk First), is an operation mode in which the identification Tag is energized and then repeatedly transmits its own ID data to the reader device. Both modes of transmission have advantages and also bring about different limiting factors.

Firstly, temperature data, pulse data and sensor-related calibration parameters are read from the built-in storage of the electronic tag, which is a natural application of the downlink instruction mode. From an energy level division perspective, the input energy level that enables the downstream command mode operation is also generally sufficient to meet the input energy level required for temperature and pulse measurements, in other words, the temperature and pulse measurement data obtained at this energy level is more reliable because the performance of the circuit is guaranteed at higher energy levels; however, the standard ISO 11784/11785 does not specify the command format of the downlink command, and each manufacturer uses the communication command defined by the manufacturer to transmit the downlink command, so that the downlink command of the electronic tag of each manufacturer in the market is incompatible, thereby limiting the compatibility of the card reader and creating a market barrier for application and popularization; furthermore, the terminal client must upgrade the hardware of the card reader, so that the operation of issuing the advanced instruction can be executed, and meanwhile, driving software is written for each different downlink instruction, thereby increasing the difficulty of system integration of the terminal user; furthermore, the downlink instruction working mode is a single communication process initiated by the card reader, which requires the electronic tag to successfully demodulate the received instruction, and to operate according to the instruction and then to follow a handshake protocol and time sequence with the card reader for feedback response; the success rate of the communication process is objectively and greatly smaller than that of an uplink data transmission mode of repeatedly and circularly transmitting ID data, and the phenomenon that the operation cannot be completed due to failure of receiving and demodulating in downlink communication often exists in user experience, so that the success rate of the downlink command mode communication is reduced. In contrast, the uplink data transmission mode has the characteristic of higher communication success rate, and the international standard of ISO 11784/11785 standardizes the data format of uplink communication, so that the label products produced by different electronic label manufacturers conform to the same uplink data transmission format, the method is generally applied to all card reader devices meeting the ISO 11784/11785 standard on the market, the terminal user only needs to expand and collect further temperature and pulse measurement data and consistency calibration parameter data related to a sensor on the basis of the ISO data code stream of the receiving standard, and a series of floating point number operation is carried out on the RFID card reader to obtain temperature readings and heartbeat pulse readings in degrees centigrade, thereby forming the advantage of application and popularization. The uplink data transmission mode often has lower power consumption than the downlink advanced instruction mode, which is a technical challenge, but the functions of temperature and pulse measurement and analog-to-digital conversion can be completed at the energy level of the uplink data transmission by adopting the low-power chip design and the signal processing technology which are the most top in the industry today.

Therefore, the current industry state of the animal identification field with the low frequency of 134.25 kHz and the market popularization practice show that the acquisition of the sensing information of temperature and pulse in the uplink data transmission mode is quite desirable. This is because the uplink data transmission mode and the downlink instruction mode have objectively very different user experiences. In the uplink data transmission mode, because of the characteristic of repeatedly and circularly transmitting TTF data, a user can receive repeated updated data of tens of milliseconds on a card reader terminal, and a buzzer generates a sound as a response after the card reader is received once, so that the user experiences a real-time and smooth updated data acquisition and stable display experience on the card reader terminal; the downlink instruction mode needs to send out an advanced instruction by the card reader, the temperature sensing tag needs to carry out the processes of receiving and demodulating, then carries out temperature and pulse measurement according to the instruction, and then feeds back to the card reader terminal in the form of binary code stream after quantization, which is a one-time response process to the single advanced instruction, and the downlink communication success rate is smaller than that of the uplink data transmission mode, so that the user experience of the card reader terminal is not blocked and the response is insensitive. Finally, the function of issuing instructions by the card reader also provides higher requirements for hardware of the card reader, and the function of issuing instructions by the card reader becomes a market barrier for transmitting temperature and pulse sensing information in a downlink communication mode under the trend that the market of the existing card reader is pursuing more and more simplicity and low cost.

Although the uplink data transmission mode is quite promising, the transmission mode still has problems. The fixed cycle of the uplink data transmission mode specified by the international standard ISO11784/11785 is that the data with fixed bit number is repeatedly transmitted, for example, the uplink transmission 128-bit animal identification code specified by the international standard ISO11784/11785 shown in fig. 1 sequentially includes a code stream start frame head with 11 bits, an identification code with 64 bits and 8 groups sequentially transmitted and each group has a total 72 bits of 1 bit interval respectively, an identification code with 16 bits and 2 groups sequentially transmitted and each group has 18 bits CRC (Checksum Redundancy Check) check codes with 1 bit interval respectively, and the rest 24 bits and 3 groups are transmitted and each group has 27 bits of spare tail codes with 1 bit interval respectively; wherein the first three parts are data which are necessary to be contained in the specification of the ISO11784/11785 protocol, and the rest 27 bit tail codes are not specified; seemingly available for transmitting data such as temperature and pulse measurements, but only a 27-bit free bit number is insufficient to store binary data of temperature or pulse measurements, as well as binary data of several key calibration parameters related to the sensor.

Specifically, taking a temperature sensor implemented in patent CN201811212762.2, "a method for improving measurement accuracy of a semiconductor temperature sensor", as an example, temperature data required to be transmitted by the temperature sensor, and calibration parameters related to the temperature sensor, include four floating point numbers including a temperature specific physical quantity X, a slope calibration parameter value a, an offset calibration parameter B, and an internal current specific design parameter α, and under the condition that requirements of measurement and calculation accuracy are satisfied, a binary conversion of 16 binary numbers to represent one floating point number requires at least 64 binary free digits in the positions of free end codes to represent the four floating point numbers.

Taking a pulse sensor as an example, in short, the measurement of pulse is the measurement of time. Referring To the signal processing method discussed in the academic works "Time-To-Digital Converters" by Stephan Henzler in the advanced microelectronic series books published by Springer publishing in 2010, (Time-To-digital converter, ISBN 978-90-481-8627-3), the pulse sensor may define a period To be quantitatively measured with a first pulse Time triggered by one pulse signal acquired by the ECG electrode pad as a Time start and a second pulse Time triggered by the other pulse as a Time end, and convert the period into an analog voltage signal; then the voltage signal is sampled at high speed by a high-frequency clock signal, and the number of clock pulses in the sampling period is obtained by a counter synchronous with the clock signalA binary representation of the measured value N of the length of the time period. In order to make the measurement result not affected by the Process fluctuation (Process), the Voltage of the power supply (Voltage) and the Temperature of the measurement environment (Temperature), PVT (for short), the signal link from the pulse signal to the binary quantitative measurement for the above time period often adopts a differential structure, that is, two signals converted from time to analog Voltage are input to a Voltage comparator with a differential pair tube structure, and the output Voltage of the Voltage comparator synchronized with the clock signal is inverted to end the counting Process. In the signal processing architecture, on one hand, the longer the measurement time is, the more accurate the measurement result is; on the other hand, the higher the sampling clock frequency is, the larger the number of pulses obtained by measurement is, and the more accurate the measurement result is. In order to obtain a preferable measurement accuracy, the integer count value N of the counter is often a larger integer, for example, the maximum available number is 256, and the integer count value N needs to be represented by an 8-bit binary number. Further, as can be seen from the basic principle of analog signal processing, the delay time difference epsilon between two signal links _T Offset error V inherent to sum voltage comparator _os Is the main physical quantity of the pulse sensor which needs to be calibrated. Delay time difference epsilon between two differential signal links _T The offset error Vos inherent to the voltage comparator can be obtained by sampling the clock at a high speed to obtain an integer value N representing the number of clock cycles, i.e. the number of pulses _ε And N _os In order to obtain a more optimal measurement accuracy, these two parameters also need to be represented by binary numbers of at least 8 bits, respectively. Plus the number of CRC calibration bits, and the number of bits required for the space code, the 27-bit tail code left free in 128 bits of the ISO11784/11785 standard is also insufficient.

Obviously, the existing passive radio frequency identification tag transmission technology and the existing ISO11784/11785 technical standard do not solve the problem, and particularly the uplink code stream format fails to consider the requirement of data transmission of a high-precision temperature sensor, so that the uplink transmission mode with higher communication success rate cannot be effectively popularized in the application of the passive sensor radio frequency identification tag integrated chip, which is a problem to be solved urgently.

For passive digital systems, the best way to switch modes of operation between complex modes is through a finite state machine (Finite State Machine, FSM for short). The finite state machine is a system modeling tool commonly used in computer science, and can clearly express the sequence of several working states of the system and the switching and jumping ways. Conventional digital control logic compliant with ISO11784/11785 radio frequency identification tags employs a finite state machine mechanism as shown in fig. 2.

As can be seen from fig. 2, in the prior art, once the rfid tag enters the actively transmitting TTF mode, the TTF data is repeatedly transmitted in a relatively simple cycle until the rf field is turned off, and the passive tag stops working due to the loss of energy. Under such a simple mechanism, measurement data and calibration data related to temperature or pulse sensing cannot be added to the cyclically repeated upstream data stream.

The technology of the application starts from a finite state machine control mechanism of the radio frequency identification tag, and by providing a plurality of flexible and configurable finite state machine control mechanisms, the technology expands an uplink transmission mode on the basis of conforming to the ISO 11784/11785 protocol, and transmits the temperature required by sensing, pulse measurement data and sensor calibration data in a repeated and cyclic transmission mode.

Disclosure of Invention

The application aims to provide a method for automatically sending a sensor data code stream by an RFID tag, which is used for circularly and repeatedly sending measurement data with sensing information and calibration parameter data related to a sensor to data reading equipment by using a mode of uplink transmission of a radio frequency identification tag so as to achieve the aim of improving the communication reliability of a passive wireless sensor.

In order to achieve the above purpose, the technical scheme adopted by the invention is as follows: the method for automatically sending sensor data code stream by the RFID tag comprises the steps that the sensor data code stream is a composite data code stream formed by combining standard data codes containing ISO 11784/11785 and measurement and calibration data code streams with sensing information, and different configurations can be carried out on the composite data code stream respectively through preset values in a storage unit of the RFID tag according to application requirements;

the method for sending the sensor data code stream to the data reading device by the RFID tag is a method for circularly and repeatedly sending the composite data code stream to the data reading device by the RFID tag under the control of a finite state machine, or a method for circularly and repeatedly sending the composite data code stream to the data reading device by the RFID tag according to a fixed operation flow, so as to achieve the aim of improving the communication reliability of the passive wireless sensor.

The method for circularly and repeatedly sending the composite data code stream to the data reading equipment under the control of the finite state machine comprises the steps that the finite state machine of the RFID label sequentially executes processes of starting, resetting a label system, ready labels, receiving instructions, operating after being selected and keeping silent, the system enters an extended TTF process after the ready labels, the extended TTF process comprises a process that the RFID label circularly and repeatedly sends the composite data code stream to the data reading equipment under the control of the finite state machine, the composition form of the composite data code stream is determined by configuration information read by the data reading equipment, and the composite data code stream is circularly and repeatedly sent to the data reading equipment by using a mode of uplink transmission of the radio frequency identification label so as to achieve the aim of improving the communication reliability of the passive wireless sensor.

The technical scheme for realizing the aim of the invention further comprises that the data reading equipment reads a storage unit array of the RFID tag, reads the configuration page information of the finite state machine from a specific address of the storage unit array, and extracts a configuration information value according to the configuration page information;

the first configuration mode of the configuration information value is to combine a plurality of uplink code streams sent by the RFID tag to the data reading equipment into a group, wherein each uplink code stream respectively contains 101-bit standard data codes and 27-bit tail codes, a plurality of parameters which are related to a sensor and correspond to the plurality of uplink code stream numbers are respectively embedded into the plurality of uplink code streams as the tail codes in a one-to-one correspondence manner to form composite data code streams in an ISO 11784/11785 standard format, and the composite data code streams are circularly and repeatedly sent to the data reading equipment;

the second configuration mode of the configuration information value is to combine a 128-bit ISO 11784/11785 standard data code and a 128-bit sensing data composite uplink code stream into a group of composite data code streams, wherein the sensing data composite uplink code stream is a 128-bit code stream structure formed by a plurality of parameters related to sensing, a 16-bit characteristic initial frame header, an 8-bit CRC check code and an interval space code required in the middle, each parameter is represented by a 16-bit binary number, 8 bits are used as a byte unit, interval spaces are reserved between each byte unit, and a total of 16-bit CRC check codes are used for transmission check of all data in the transmission process.

Further, the method for the RFID tag to circularly and repeatedly transmit the composite data code stream to the data reading device according to the fixed operation flow comprises the following steps:

S ₁ : the RFID tag transmits a composite data code stream-1 composed of an ISO 11784/11785 standard data code of 101 bits and a 27-bit tail code group containing a sensor parameter-1 to a data reading device;

S ₂ : the RFID tag transmits a composite data code stream-2 composed of an ISO 11784/11785 standard data code of 101 bits and a 27-bit tail code group containing a sensor parameter-2 to a data reading device;

……

S _N : the RFID tag transmits a composite data code stream-N composed of an ISO 11784/11785 standard data code of 101 bits and a 27-bit tail code group containing a sensor parameter-N to a data reading device;

S _N+1 : returning to step S ₁ ；

And repeating the steps in a circulating way until the radio frequency field of the data reading device is turned off.

Or, the method for the RFID tag to circularly and repeatedly send the composite data code stream to the data reading equipment according to the fixed operation flow comprises the following steps:

S ₁ : the RFID tag transmits 128-bit standard data codes to the data reading device according to the ISO 11784/11785 standard;

S ₂ : the RFID tag transmits 128-bit sensing data composite uplink code stream to the data reading equipment;

S ₃ : returning to step S ₁ ；

The invention provides a method for automatically transmitting sensor data code stream by an RFID tag, which provides a logic control mechanism for integrating the sensor into a passive radio frequency identification tag chip, wherein the logic control mechanism can be implemented in the form of a flexibly configurable finite state machine, can also be implemented in the form of sequentially executed operation steps or processes, and circularly and repeatedly transmits measurement data with sensing information and calibration parameter data related to the sensor to data reading equipment in a mode of uplink transmission of the radio frequency identification tag, thereby improving the communication reliability of the passive radio frequency identification tag and obtaining smooth user experience.

Drawings

FIG. 1 is an animal identification upstream format specified by International Standard ISO 11784/11785;

FIG. 2 is a prior art finite state machine for RFID tags compliant with the ISO 11784/11785 standard;

FIG. 3 illustrates a process for reading extended transmit control mode configuration information from a particular address page of a non-volatile memory cell array embedded in a passive RFID tag;

FIG. 4 is a process of reading extended transmission control mode configuration information from a specific address page of a nonvolatile memory cell array according to a first embodiment of the present invention;

FIG. 5 is a flowchart of a first implementation of a RFID tag finite state machine according to an embodiment of the present invention;

FIG. 6 is a configuration information value of the finite state machine of FIG. 5;

FIG. 7 is a flowchart of a second implementation of a RFID tag finite state machine according to an embodiment of the present invention;

FIG. 8 is a configuration information value of the finite state machine of FIG. 7;

FIG. 9 is a flowchart of a third implementation of a RFID tag finite state machine according to an embodiment of the present invention;

FIG. 10 is a configuration information value of the finite state machine of FIG. 9;

FIG. 11 is another configuration value of the configuration information values of the finite state machine of FIG. 9;

FIG. 12 is a flowchart of a fourth implementation of a RFID tag finite state machine according to an embodiment of the present invention;

FIG. 13 is a configuration information value of the finite state machine of FIG. 12;

FIG. 14 is a block diagram of an exemplary time-to-digital converter according to a second embodiment of the present invention;

FIG. 15 is a schematic diagram of time domain waveforms corresponding to respective nodes in the block diagram of FIG. 13;

FIG. 16 is a timing diagram of a high-speed clock signal sampling and counting a period of time;

FIG. 17 is a diagram showing the comparison of the structure of the FDX mode and the HDX mode data streams;

fig. 18 is a data code stream structure diagram in HDX mode.

Description of the embodiments

The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

The invention relates to a method for automatically sending a sensor data code stream by an RFID tag, wherein the sensor data code stream is a composite data code stream formed by combining standard data codes containing ISO 11784/11785 and measurement and calibration data code streams with sensing information, and the composite data code stream can be configured differently according to application requirements by preset values in an RFID tag storage unit;

Fig. 3 shows a process of reading extended transmission control mode configuration information from a specific address page of a nonvolatile memory cell array in which a passive RFID tag is built, in which the data reading device reads the memory cell array of the RFID tag, reads finite state machine configuration page information from the specific address of the memory cell array, and extracts configuration information values 1 to N according to the configuration page information.

Example 1

Fig. 4 is a process of reading configuration information of an extended transmission control mode in a specific address page of a non-volatile memory cell array according to a first embodiment of the present invention, where in this embodiment, when a data reading device reads an RFID tag by integrating a temperature sensor in the RFID tag, the tag encodes standard data including ISO 11784/11785, and a composite data code stream formed by combining measurement and calibration data code streams with temperature sensing information, and the data reading device repeatedly sends the composite data code stream in a mode cycle of uplink transmission of a radio frequency identification tag. In this mode, the configuration information values shown in fig. 3 include four parameters of temperature measurement ratio data X, slope calibration parameter a, offset calibration parameter B, and internal current ratio calibration parameter α, as shown in fig. 4.

As shown in fig. 5, the present technology expands the part of the active transmission TTF mode of the tag based on the conventional finite state machine of the radio frequency identification tag according to the standard ISO 11784/11785 shown in fig. 2, instead of simply and cyclically and repeatedly transmitting the animal identification data of the standard ISO 11784/11785, the present technology first reads the data of the memory unit stored in a specific address in the non-volatile memory unit array to obtain the configuration information of the expanded transmission control mode, then, the radio frequency identification tag cyclically and repeatedly transmits the composite data code stream to the data reading device under the control of the finite state machine shown in fig. 5, sequentially executes the processes of starting, resetting the tag system, ready, receiving the instruction, operating and keeping silent after being selected for the RFID tag finite state machine, and the system enters an extended TTF process after the tag ready process, where the RFID tag cyclically and repeatedly transmits the composite data code stream to the data reading device under the control of the finite state machine, and the configuration form of the composite data code stream is determined by the RFID tag under the control of the finite state machine, and the configuration information is cyclically and repeatedly transmitted to the radio frequency reading device by the radio frequency identification device by the composite data code stream to achieve the passive transmission destination radio frequency identification device. The composite data code stream is divided into a plurality of different organization forms so as to meet the application requirements of different users.

Before we elaborate on the present solution, it should be pointed out first that, in a passive rfid tag with integrated temperature sensing function, the task of temperature measurement with the rfid tag is performed before the data transmission takes place. The technique of the present application does not relate to the control manner of starting the temperature measurement, and here we can simply consider that the temperature measurement is started and performed immediately after the passive rfid tag is powered on and reset, and when the tag enters the state of "tag ready" in the finite state machine shown in fig. 5, the temperature measurement information is already stored in the register or the nonvolatile memory unit of the tag system, and the calibration parameters related to the sensor are also stored in the register or the nonvolatile memory unit of the tag system.

The first configuration mode of the configuration information value corresponds to the finite state machine shown in fig. 5 and the uplink code stream structure shown in fig. 6, which is to combine every four uplink code streams sent by the RFID tag to the data reading device into a group, and each uplink code stream contains 101-bit standard data codes and 27-bit tail codes, and four parameters related to temperature sensing: namely, temperature measurement ratio data X, slope calibration parameter A, offset calibration parameter B and internal current ratio calibration parameter alpha are respectively used as tail codes to be embedded into the four uplink code streams to form a composite data code stream in an ISO 11784/11785 standard format, and the composite data code stream is circularly and repeatedly sent to data reading equipment.

As shown in fig. 6, the process of sending the composite data code stream repeatedly to the data reading device is that the composite data code stream-1, the composite data code stream-2, the composite data code stream-3 and the composite data code stream-4 are sequentially sent by the radio frequency identification tag in the uplink data transmission mode, and after the composite data code stream-4 is sent, the composite data code stream-1 is sent again, and the process is repeated until the radio frequency field sent by the data reading device is turned off. Without loss of generality, the parameter sequence contained in the tail codes in the composite data code stream-1 to the composite data code stream-4 in fig. 6 may be any arrangement sequence of the four parameters, and other related parameters, such as time stamp data associated with temperature data, may also be used as the tail code of the composite data code stream-5 in this form, and be sent along with the composite data code stream-1, the composite data code stream-2, the composite data code stream-3, the composite data code stream-4 and the composite data code stream-5, according to the requirements of advanced applications. When the sequence of the parameters of the temperature sensor contained in the tail code is not fixed, the card reader equipment can easily distinguish which one of the currently received parameters is only required to define the characteristic data format on the format of the parameter data. For example, the characteristic data format of the prescribed parameter X is data with a fixed 00 as a preamble, the characteristic data format of the prescribed parameter a is data with a fixed 01 as a preamble, and so on. In this manner, the reader device firmware need only be updated to receive the tail code in the 128 bits of data and collect the parameters required for the pattern specification depending on the configuration pattern setting to obtain complete temperature data. Because the sending mode is carried out in the repeated and circulated data transmission mode, the communication success rate is higher than that of a card reader first-to-talk (RTF) mode, and the user experience is improved.

The second configuration mode of the configuration information value is a transmission mode corresponding to the finite state machine shown in fig. 7 and the uplink code stream structure shown in fig. 8, and each two uplink code streams are combined into a group, and each uplink code stream contains 101-bit standard data codes and 27-bit tail codes, and two parameters related to temperature sensing: namely, temperature measurement ratio data X and offset calibration parameters B are respectively used as tail codes to be embedded into the two uplink code streams to form a composite data code stream in an ISO 11784/11785 standard format, and the composite data code stream is circularly and repeatedly sent to data reading equipment.

The difference from the configuration 1 is that only two parameters of temperature measurement ratio data X and offset calibration parameter B are used as tail codes of standard data codes of ISO 11784/11785, and are respectively embedded into tail codes of standard data codes of ISO 11784/11785 transmitted twice and transmitted. This simplified mode is based on observations and experience in several respects. Firstly, the influence of the offset calibration parameter B on the finally calculated temperature value exceeds the influence of other calibration parameters by at least one order of magnitude in the three calibration parameters related to the sensor, so that the value of the slope parameter A can be calculated from the statistical average value of the current chip batch without distinguishing for each RFID tag temperature sensor; secondly, for the semiconductor integrated manufacturing process, the value of the internal current ratio parameter α is relatively stable and has a very small statistical standard deviation, so that the value α can be obtained by calibration measurement of the previous batch of products, and is not required to be transmitted as a separate sensor parameter.

As shown in fig. 8, the composite data code stream-1 and the composite data code stream-2 are sequentially sent by the radio frequency identification tag in the uplink data transmission mode according to the time sequence of the sending, and after the composite data code stream-2 is sent, the composite data code stream-1 is sent again, and the cycle is always performed until the radio frequency field sent by the data reading device is turned off. Without loss of generality, the parameter sequence included in the tail codes in the composite data code stream-1 and the composite data code stream-2 in fig. 8 may be any arrangement sequence of the temperature measurement ratio parameter X and the offset calibration parameter B, and other related parameters, such as time stamp data associated with temperature data, may also be used as the tail code of the composite data code stream-3 in this form, and be sent together with the composite data code stream-1, the composite data code stream-2 and the composite data code stream-3 according to the requirements of advanced applications. When the sequence of the parameters of the temperature sensor contained in the tail code is not fixed, the card reader equipment can easily distinguish which one of the currently received parameters is only required to define the characteristic data format on the format of the parameter data. For example, the characteristic data format of the prescribed parameter X is data with a fixed 00 as a preamble, the characteristic data format of the prescribed parameter a is data with a fixed 01 as a preamble, and so on. In this manner, the reader device firmware need only be updated to receive the tail code in the 128 bits of data and collect the parameters required for the pattern specification depending on the configuration pattern setting to obtain complete temperature data. Because the sending mode is carried out in the repeated and circulated data transmission mode, the communication success rate is higher than that of a card reader first-to-talk (RTF) mode, and the user experience is improved.

The third configuration mode of the configuration information value corresponds to the finite state machine shown in fig. 9 and the 128-bit composite uplink code stream structure shown in fig. 10, which combines a 128-bit ISO 11784/11785 standard data code and a 128-bit temperature sensing data composite uplink code stream into a group of composite data code streams, wherein the temperature sensing data composite uplink code stream is formed by four parameters related to temperature sensing: namely, temperature measurement ratio data X, slope calibration parameter A, offset calibration parameter B, internal current ratio parameter alpha, a 128-bit code stream structure consisting of a 16-bit characteristic initial frame header, 8-bit CRC check code and a space code required in the middle, wherein each parameter is represented by 16-bit binary numbers, 8 bits are used as a byte unit, space gaps are reserved among each byte unit, and a total of 16-bit CRC check codes are used for transmission check of all data in the transmission process.

As shown in fig. 10, the 128-bit ISO 11784/11785 standard data codes in the composite data code stream and the 128-bit temperature sensing data composite uplink code stream form two code streams which are alternately transmitted, after the standard data codes are transmitted, the temperature sensing data composite uplink code stream is started to be transmitted, then the standard data codes are transmitted, and the cycle is always performed until the radio frequency field sent by the data reading device is turned off. Alternatively, the finite state machine protocol may choose to transmit or not transmit the last 20 (i.e., 108 th to 127 th) undefined portion of the upstream of the temperature sensor data complex.

Without loss of generality, the parameter sequences included in the temperature sensing data composite uplink code stream in fig. 10 may be any of the indicated temperature measurement ratio parameter X, slope calibration parameter a, offset calibration parameter B, and internal current ratio calibration parameter α, arranged in the time sequence of transmission.

In a general temperature sensor application, decimal temperature values represented by 16-bit binary numbers can meet the general application, and a data code stream example taking the 16-bit binary numbers as elements is given in fig. 10; in some higher precision temperature sensor applications, the analog-to-digital converter of the temperature sensor is often divided into a coarse conversion and a fine conversion with local amplification, and the integer part and the fraction part of the measured temperature data X part are often represented by separate multi-bit binary numbers, such as an 8-bit binary number with a sign bit for the integer part and a 16-bit binary number for the fraction part, respectively. At this time, the X data in fig. 10 is changed from a 16-bit binary code plus 2-bit space code to a 24-bit binary code plus 3-bit space code, and accordingly the total bit number of the overall composite code stream is increased by 9 bits from the code stream shown in fig. 10 (not shown here).

Taking the code stream structure shown in fig. 10 as an example, when the order of the parameters of the temperature sensor included in the temperature sensor data composite uplink code stream is not fixed, the data reading device can easily distinguish which parameter is currently received by only defining the characteristic data format on the format of the parameter data. For example, the characteristic data format of the prescribed parameter X is data with a fixed 00 as a preamble, the characteristic data format of the prescribed parameter a is data with a fixed 01 as a preamble, and so on. Thus, the total code stream length of the characteristic data bits representing the parameter definition is extended from 108 bits in the 128-bit code segment shown in fig. 10 to 120 bits in the 128-bit code segment shown in fig. 11. It is obvious that each temperature parameter is expanded from original 16-bit data to 18-bit data, and the corresponding space code is increased by 1 bit on the basis of the previous example. Alternatively, the finite state machine protocol may choose to transmit or not transmit the last 8 (i.e., 120 th to 127 th) undefined portion of the upstream of the temperature sensor data complex.

In this configuration mode, the data reading device firmware only needs to be updated to receive 128-bit ISO standard data at intervals in sequence, and to receive 128-bit temperature parameter data, and the complete temperature data can be obtained by alternating repetition. Because the transmission mode is carried out in the repeated and circulated data transmission mode, the communication success rate is higher than that of a card reader first-to-talk (RTF) mode, and the user experience is improved.

The fourth configuration mode of the configuration information value corresponds to the finite state machine shown in fig. 12 and the 72-bit composite uplink code stream structure shown in fig. 13, and the fourth configuration mode combines a 128-bit ISO 11784/11785 standard data code and a 128-bit temperature sensing data composite uplink code stream into a group of composite data code streams, wherein the temperature sensing data composite uplink code stream is formed by two parameters related to temperature sensing: namely temperature measurement ratio data X, offset calibration parameter B, a 72-bit composite data code stream structure consisting of a 16-bit characteristic initial frame header, a 16-bit CRC check code and a space code required in the middle, wherein each parameter is represented by 16-bit binary numbers, 8 bits are used as a byte unit, space gaps are reserved between each byte unit, and a total of 16-bit CRC check codes are used for transmission check of all data in the transmission process.

Compared with the finite state machine of fig. 9 corresponding to the third configuration mode, the fourth configuration mode has simplified code stream structure, i.e. the temperature sensing data composite uplink code stream structure only comprises two parameters of temperature measurement ratio data X and offset calibration parameter B. This simplified mode is based on observations and experience in several respects. Firstly, the influence of the offset calibration parameter B on the finally calculated temperature value exceeds the influence of other calibration parameters by at least one order of magnitude in the three calibration parameters related to the sensor, so that the value of the slope parameter A can be calculated from the statistical average value of the current chip batch without distinguishing for each RFID tag temperature sensor; secondly, for the semiconductor integrated manufacturing process, the value of the internal current ratio parameter α is relatively stable and has a very small statistical standard deviation, so that the value α can be obtained by calibration measurement of the previous batch of products, and is not required to be transmitted as a separate sensor parameter.

Without loss of generality, the parameter sequence included in the temperature sensing data composite uplink code stream in fig. 13 may be any sequence of the temperature measurement ratio parameter X and the offset calibration parameter B.

In a general temperature sensor application, decimal temperature values represented by 16-bit binary numbers can meet the general application, and a data code stream example taking the 16-bit binary numbers as elements is given in fig. 13; in some higher precision temperature sensor applications, the analog-to-digital converter of the temperature sensor is often divided into a coarse conversion and a fine conversion with local amplification, and the integer part and the fraction part of the measured temperature data X part are often represented by separate multi-bit binary numbers, such as an 8-bit binary number with a sign bit for the integer part and a 16-bit binary number for the fraction part, respectively. At this time, the X data in fig. 13 is changed from a 16-bit binary code plus 2-bit space code to a 24-bit binary code plus 3-bit space code, and accordingly the total bit number of the overall composite code stream is increased by 9 bits from the code stream shown in fig. 10 (not shown here).

Taking the code stream structure shown in fig. 13 as an example, when the order of the parameters of the temperature sensor included in the uplink code stream of the temperature sensor data combination is not fixed, the card reader device can easily identify which parameter is currently received by only defining the characteristic data format on the format of the parameter data. For example, the characteristic data format of the predetermined parameter X is data with a fixed 00 as a preamble, and the characteristic data format of the predetermined parameter B is data with a fixed 01 as a preamble. Thus, the total code stream length of the characteristic data bits representing the parameter definition is increased from 72 bits to 78 bits as shown in fig. 13. It is obvious that each temperature parameter is expanded from original 16-bit data to 18-bit data, and the corresponding space code is increased by 1 bit on the basis of the previous example.

In this configuration mode, the reader device firmware need only be updated to receive 128 bits of ISO standard data at sequential intervals, and to receive 72 bits of temperature parameter data, alternately and repeatedly, to obtain complete temperature data. Because the secondary transmission mode is carried out in the repeated and circulated data transmission mode, the communication success rate is higher than that of a card reader first-to-talk (RTF) mode, and the user experience is improved.

The embodiment of the application is a method for controlling the uplink transmission of the data related to the temperature sensor by using a flexibly configured finite state machine mechanism, and meanwhile, the application also provides a method for circularly and repeatedly transmitting the composite data code to the data reading equipment by the RFID tag according to a fixed operation flow. Taking the uplink data transmission scheme shown in fig. 6 corresponding to the configuration value 1 in the present technology as an example, the scheme can be implemented by the following operation method:

the method for circularly and repeatedly transmitting the composite data code stream to the data reading equipment by the RFID tag according to the fixed operation flow comprises the following steps:

S ₁ : the RFID tag transmits a composite data code stream-1 composed of an ISO 11784/11785 standard data code of 101 bits and a 27-bit tail code group containing a temperature sensor parameter-1 to a data reading device;

S ₂ : the RFID tag transmits a composite data code stream-2 composed of an ISO 11784/11785 standard data code of 101 bits and a 27-bit tail code group containing a temperature sensor parameter-2 to a data reading device;

s3: the RFID tag transmits a composite data code stream-3 composed of an ISO 11784/11785 standard data code of 101 bits and a 27-bit tail code group containing a temperature sensor parameter-3 to a data reading device;

s4: the RFID tag transmits a composite data code stream-4 composed of an ISO 11784/11785 standard data code of 101 bits and a 27-bit tail code group containing a temperature sensor parameter-4 to a data reading device;

s5: returning to step S ₁ ；

Likewise, the uplink data transmission scheme shown in fig. 8 corresponding to the configuration value 2 may be implemented by the following operation method:

S ₃ : returning to step S ₁ ；

Further, the uplink data transmission schemes shown in fig. 10, 11 and 13 corresponding to the configuration value 3 and the configuration value 4 can be implemented by the following operation methods:

S ₁ : the RFID tag transmits 128-bit standard data codes to the data reading device according to the ISO11784/11785 standard;

S ₂ : the RFID tag transmits 128-bit temperature sensing data composite uplink code stream to the data reading equipment;

S ₃ : returning to step S ₁ ；

The temperature sensing data composite uplink code stream is a 128-bit code stream structure composed of a plurality of parameters related to temperature sensing, a 16-bit characteristic initial frame header, an 8-bit CRC check code and a space code required in the middle, wherein each parameter is represented by 16-bit binary numbers, 8 bits are used as a byte unit, space gaps are reserved among each byte unit, and a total of 16-bit CRC check codes are used for transmission check of all data in the transmission process.

It is clear that in the digital logic design of an integrated circuit, simple operation step flow logic and finite state machine logic will generate logic circuits of different forms in the logic synthesis stage, which belong to different design ideas and design methods, and the differences in the methodologies of which are not discussed here.

Example two

The temperature sensor parameters listed in the first embodiment are the temperature measurement ratio data X, the slope calibration parameter a, the offset calibration parameter B, and the internal current ratio calibration parameter α, and based on the same principle, the four configuration information values in the first embodiment can be calculated as the counter output value N, N of the time-to-digital converter for the pulse sensor _ε And N _os The implementation flow of the finite state machine and the transmission flow of the configuration information value are identical to those of the first embodiment, and are not described here again.

Referring To the academic works of Stephan Henzler in advanced microelectronic series books published by Springer publishing in 2010, "Time-To-Digital Converters" (Time-To-digital converter, ISBN 978-90-481-8627-3), a diagram of the Time-To-digital converter of the core of a typical pulse sensor is shown in fig. 14. In the figure, the start and stop signals are triggered by two pulses detected by an Electrocardiogram (ECG) electrode pad, respectively, at intervals. The system control logic of the pulse sensor gives up and down signals for respectively performing an integral operation in two periods of time, converting the pulse period of time into voltage signals V+ and V-, which are linearly related to time, and V+ and V-as differential input signals of a voltage comparator to input the signals to a tube, so that the comparator obtains a comp signal, and EN rising edges and EN falling edges related to the input signals, and the period of time identified by the EN signal is sampled by a reference clock signal ref. In the time domain, the voltage waveforms of the nodes and their timing relationships to each other are shown in fig. 15. Further, the process of sampling the start/stop signal by the reference clock signal CP (i.e., ref. Clock in fig. 14) signal, which is equivalent to the process of sampling the rising and falling edges of the EN signal, is shown in fig. 16.

In this circuit architecture, the pulse sensor may define a period to be quantitatively measured with a first pulse time triggered by one pulse signal acquired by the ECG electrode pad as a time start point (start signal rising edge) and a second pulse time triggered by the other pulse as a time end point (stop signal rising edge), and convert the period into analog voltage signals (up and down signals); then, a high-frequency clock signal (ref. Clock, CP signal) is used to sample the voltage signal at high speed, and a counter synchronous with the clock signal is used to obtain the number Y of clock pulses in the sampling period, so as to obtain a measurement value N which is binary and expresses the length of the period. In order to make the measurement result not affected by the Process fluctuation (Process), the Voltage of the power supply (Voltage) and the Temperature of the measurement environment (Temperature), PVT (for short), the signal link from the pulse signal to the binary quantitative measurement for the above time period often adopts a differential structure, that is, two signals converted from time to analog Voltage are input to a Voltage comparator with a differential pair tube structure, and the output Voltage of the Voltage comparator synchronized with the clock signal is inverted to end the counting Process. In the signal processing architecture, on one hand, the longer the measurement time is, the more accurate the measurement result is; on the other hand, the higher the sampling clock frequency is, the larger the number of pulses obtained by measurement is, and the more accurate the measurement result is. In order to obtain a preferable measurement accuracy, the integer count value N of the counter is often a larger integer, for example, the maximum available number is 256, and the integer count value N needs to be represented by an 8-bit binary number. Further, as can be seen from the basic principle of analog signal processing, the delay time difference epsilon between two signal links _T Sum voltage ratioOffset error V inherent to comparator _os Is the main physical quantity of the pulse sensor which needs to be calibrated. Delay time difference epsilon between two differential signal links _T The offset error Vos inherent to the voltage comparator can be obtained by sampling the clock at a high speed to obtain an integer value N representing the number of clock cycles, i.e. the number of pulses _ε And N _os In order to obtain a more optimal measurement accuracy, these two parameters also need to be represented by binary numbers of at least 8 bits, respectively. Here, the pulse sensor parameter is N, N _ε And N _{os ,} Respectively marked as pulse sensor parameter-1, pulse sensor parameter-2, and pulse sensor parameter-3 _。

Also, the method for automatically and circularly transmitting the pulse sensor data code stream by using the RFID tag in the embodiment comprises the following steps:

S ₁ : the RFID tag transmits a composite data code stream-1 composed of an ISO 11784/11785 standard data code of 101 bits and a 27-bit tail code group containing a pulse sensor parameter-1 to a data reading device;

S ₂ : the RFID tag transmits a composite data code stream-2 composed of an ISO 11784/11785 standard data code of 101 bits and a 27-bit tail code group containing a pulse sensor parameter-2 to a data reading device;

S ₃ : the RFID tag transmits a composite data code stream-3 composed of an ISO 11784/11785 standard data code of 101 bits and a 27-bit tail code group containing a pulse sensor parameter-3 to a data reading device;

S ₄ : returning to step S ₁ ；

Further, in this embodiment, the uplink data transmission scheme shown in fig. 10, 11 and 13 corresponding to the configuration value 3 and the configuration value 4 in the first embodiment may be implemented by the following operation method:

S ₂ : the RFID tag transmits 128 bits to the data reading devicePulse sensing data is compounded with an uplink code stream;

S ₃ : returning to step S ₁ ；

It should be noted that, in the first embodiment and the second embodiment, the mode in which the RFID tag transmits the sensor composite data code stream to the data reading apparatus is that the RFID tag operates in an FDX (Full DupleX) mode, and the data in the mode is encoded into 128 bits according to the standard specification of ISO 11784/11785; the data code in the mode is 112 bits according to the standard specification of ISO11784/11785, as shown in fig. 17 and 18, the sensor composite data code stream sent by the RFID tag to the data reading device can also adopt the two modes, that is, the first composite data code stream is obtained by placing the standard data code of ISO11784/11785 in the first 88 bits, placing a plurality of parameters of the measurement and calibration data code stream of the sensing information in the tail code of the last 24 bits, forming N composite data code streams by the standard data code of N88 bits and the N parameters, then sequentially sending the N composite data code streams to the data reading device from the first composite data code stream, and then circularly sending the first composite data code stream again after the last composite data code stream is sent, so that the cycle is repeated until the radio frequency field of the data reading device is turned off; the second composite data code stream is an uplink code stream which occupies 112 bits by standard data code of ISO11784/11785, and the measurement of sensing information and multiple parameters of the calibration data code stream occupy 112 bits as well, the two uplink code streams are combined into a group of composite data code streams, and then the two uplink code streams are sequentially and repeatedly transmitted to the data reading equipment in a circulating way until the radio frequency field of the data reading equipment is turned off. That is, the flow and method of transmitting data streams in the HDX mode and the FDX mode are identical, and the difference is only that the two streams are structurally different.

Claims

1. The method for automatically sending the sensor data code stream by the RFID tag is characterized in that the sensor data code stream is a composite data code stream formed by combining standard data codes containing ISO 11784/11785 and measurement and calibration data code streams with sensing information, and the composite data code stream can be configured differently according to application requirements by preset values in a storage unit of the RFID tag;

2. The method of claim 1, wherein the method for the RFID tag to repeatedly and cyclically transmit the composite data code stream to the data reading device under the control of the finite state machine is that the RFID tag finite state machine sequentially executes processes of starting, resetting the tag system, ready the tag, receiving the instruction, operating after being selected, and keeping silent, the system enters an extended TTF process after the tag ready process, the extended TTF process includes a process in which the RFID tag repeatedly and cyclically transmits the composite data code stream to the data reading device under the control of the finite state machine, and the configuration form of the composite data code stream is determined by the configuration information read by the data reading device, and the composite data code stream is cyclically and repeatedly transmitted to the data reading device by using the mode of the radio frequency identification tag uplink transmission, so as to achieve the purpose of improving the communication reliability of the passive wireless sensor.

3. The method of claim 2, wherein the data reading device reads a memory cell array of the RFID tag, reads finite state machine configuration page information from a specific address of the memory cell array, and extracts a configuration information value according to the configuration page information.

4. A method according to claim 3, wherein the first configuration mode of the configuration information value is to combine a plurality of uplink code streams sent by the RFID tag to the data reading device into a group, each uplink code stream contains a 101-bit standard data code and a 27-bit tail code, a plurality of parameters related to the sensor and corresponding to the number of the plurality of uplink code streams are embedded into the plurality of uplink code streams as tail codes in a one-to-one correspondence, and form a composite data code stream in an ISO 11784/11785 standard format, and the composite data code stream is cyclically and repeatedly sent to the data reading device.

5. The method of claim 4, wherein the process of cyclically and repeatedly transmitting the composite data code stream to the data reading device is that the composite data code stream-1, the composite data code streams-2 and …, and the composite data code stream-N are sequentially transmitted by the radio frequency identification tag in the uplink data transmission mode, and the composite data code stream-1 is transmitted again after the transmission of the composite data code stream-N, and the cycle is continued until the radio frequency field transmitted by the data reading device is turned off.

6. A method according to claim 3, wherein the second configuration of the configuration information value is a 128-bit code stream structure comprising a 128-bit ISO 11784/11785 standard data code, and a 128-bit sense data composite upstream code stream, the sense data composite upstream code stream being a plurality of parameters related to sensing, a 16-bit characteristic start frame header and an 8-bit CRC check code, and an intermediate required space bit code, wherein each parameter is represented by a 16-bit binary number, 8 bits are used as a byte unit, space slots are provided between each byte unit, and a total of 16-bit CRC check codes are used for transmission check of all data during transmission.

7. The method of claim 6, wherein the standard data code and the sensing data composite uplink code in the composite data code stream form two code streams which are alternately transmitted, and the sensing data composite uplink code stream starts to be transmitted after the standard data code is transmitted, and then the standard data code is transmitted, and the cycle is performed until the radio frequency field transmitted by the data reading device is turned off.

8. The method according to claim 1, wherein the method for the RFID tag to cyclically and repeatedly transmit the composite data code to the data reading device according to a fixed operation procedure comprises:

……

S _N+1 : returning to step S ₁ ；

9. The method according to claim 1, wherein the method for the RFID tag to cyclically and repeatedly transmit the composite data code to the data reading device according to a fixed operation procedure comprises:

S ₃ : returning to step S ₁ ；

10. The method of claim 9 wherein the sensor data composite upstream is a 128 bit stream structure consisting of a plurality of parameters related to the sensor, a 16 bit characteristic start frame header and 8 bit CRC check code, and a space code required in the middle, wherein each parameter is represented by a 16 bit binary number, 8 bits are a byte unit, space spaces exist between each byte unit, and a total of 16 bits CRC check codes are used for transmission check of all data during transmission.