Multi-channel RFID read-write system applied to immunodetection module

Abstract

The multi-channel RFID read-write system comprises a central processing unit, a first universal synchronous / asynchronous serial transceiving interface (USART1) of the central processing unit is in communication connection with an upper computer through an MAX3232 transceiver, a second universal synchronous / asynchronous serial transceiving interface (USART2) of the central processing unit is connected with the input end of a multiplexing circuit, and the input end of the multiplexing circuit is connected with the input end of a wireless communication module. A general programmable I / O port (GPIO) of the central processing unit is connected with the control end of the multiplexing circuit; and the output end of the multiplexing circuit is connected with the radio frequency antenna unit through the communication conversion circuit. According to the invention, read-write operation of multi-path and multi-functional RFID is realized, the design of a control system is optimized, and the problems of detection system redundancy and resource waste caused by the fact that each radio frequency antenna needs to be matched with a set of read-write control system to read tag data of one functional antenna are solved; and long-distance signal transmission can be carried out, and the functions of detecting instrument position tracking, identity binding and data transmission are met.

Description

Technical Field

[0001] The invention relates to a multi-channel RFID reading and writing system, in particular to a multi-channel RFID reading and writing system applied to an immune detection module. Background Art

[0002] With the development of precision medicine, the number of medical sample tests has increased, which requires diagnostic testing instruments to have multi-item, multi-category pipeline testing. When multi-sample in vitro diagnostic instruments test samples, it is necessary to bind the sample holder and the test sample to facilitate real-time tracking and data transmission of the samples.

[0003] RFID is a contactless data communication based on radio frequency wireless transmission. It can realize the identity binding of sample trays and test samples in medical transportation lines, as well as the transmission and tracking of module test data. Since RFID transmits information based on high-frequency magnetic field coupling, it places high demands on the design of the RF antenna and the working environment, especially in special working environments, where the RF antenna needs to be individually impedance matched and dimensioned. For example, when contactlessly tracking the position, binding the identity, and transmitting data of test samples within a single module and between different test modules, RF antennas at different test locations and with different functions need to be matched with different impedances. At present, each RF antenna is usually matched with a set of read-write control systems to read sample tag information, which leads to redundancy and waste of resources in the test system, greatly increasing the manufacturing cost and control complexity of the test system. Summary of the invention

[0004] In view of this, the present invention provides a multi-channel RFID reading and writing system applied to an immune detection module to achieve stable operation of radio frequency antennas with different functions and a high success rate of reading tags.

[0005] To achieve the above object, the present invention adopts the following technical solutions: The multi-channel RFID reading and writing system applied to the immune detection module of the present invention comprises a central processing unit, wherein a first universal synchronous / asynchronous serial transceiver interface (USART1) of the central processing unit is connected to a host computer through a MAX3232 transceiver, a second universal synchronous / asynchronous serial transceiver interface (USART2) of the central processing unit is connected to an input end of a multiplexing circuit, a general programmable I / O port (GPIO) of the central processing unit is connected to a control end of the multiplexing circuit; and an output end of the multiplexing circuit is connected to a radio frequency antenna unit through a communication conversion circuit.

[0006] Optionally, the multiplexing circuit includes multiple MOS tubes, the source of each of the MOS tubes is respectively connected to the second universal synchronous / asynchronous serial transceiver interface of the central processing unit, the gate of each MOS tube is respectively connected to the universal programmable I / O port of the central processing unit, and the drain of each MOS tube is respectively connected to the radio frequency antenna unit via the communication conversion circuit.

[0007] Optionally, the communication conversion circuit is composed of a first full-duplex transceiver (RS422) and a second full-duplex transceiver (RS422) connected in series.

[0008] Optionally, the radio frequency antenna unit includes a plurality of antenna units with the same structure, and the antenna unit is composed of a radio frequency chip (FM17622) and a receiving circuit, a transmitting circuit, an impedance matching circuit and an antenna.

[0009] Optionally, the receiving circuit is composed of resistors R4, R5 and capacitors C9, C10; one end of the resistor R5 is connected to VMID and connected to ground GND through the capacitor C9; the other end of the resistor R5 is connected to RX and connected to one end of the capacitor C10 through the resistor R4; The transmitting circuit is composed of inductors L1, L2 and capacitors C11, C12; the capacitors C11 and C12 form a series circuit, one end of the capacitor C11 is connected to the first end of the inductor L1 and the other end of the capacitor C10 respectively, and the second end of the inductor L1 is connected to TX2; the connection point of the capacitor C11 and the capacitor C12 is connected to the ground GND; the capacitor C12 is connected to the first end of the inductor L2, and the second end of the inductor L2 is connected to TX1; the inductors L1, L2 and the capacitors C11, C12 form a low-pass filter; The impedance matching circuit is composed of capacitors C1, C2, C3, C4, C5, C6, C7, and C8; the capacitors C1 and C7 form a first capacitor parallel circuit, the capacitors C2 and C8 form a second capacitor parallel circuit, the capacitors C3 and C4 form a first capacitor series circuit, and the capacitors C5 and C6 form a second capacitor series circuit; one end of the first capacitor parallel circuit is connected to the first end of the inductor L1, and one end of the second capacitor parallel circuit is connected to the first end of the inductor L2; the first capacitor series circuit and the second capacitor series circuit are respectively connected between the other ends of the first capacitor parallel circuit and the second capacitor parallel circuit; the connection point of the capacitor C3 and the capacitor C4 and the connection point of the capacitor C5 and the capacitor C6 are respectively connected to the ground GND; The antenna is composed of two rectangular coils connected in series and resistors R1, R2, and R3; one end of the two rectangular coils connected in series is connected to the first capacitor parallel circuit through the resistor R1, and the other end of the two rectangular coils connected in series is connected to the second capacitor parallel circuit through the resistor R3, and the connection point of the two rectangular coils connected in series is connected to the ground GND through the resistor R3; R1, R2, and R3 act as differential antenna connections.

[0010] Furthermore, the radius of each rectangular coil is half of the detection distance; in actual application, the inductance and capacitance parameters of the two rectangular coils connected in series are measured by a bridge, so that the standing wave ratio reaches 1.2-1.5, so as to achieve the best antenna power transmission parameters.

[0011] The present invention adopts a control system, uses a multiplexed switching method, and adopts RS422 full-duplex communication connection to realize the read and write operations of multiple RFIDs with multiple functions; optimizes the control system design, solves the problem that each radio frequency antenna needs to match a set of read-write control systems to read the data of a functional antenna tag, and the resulting detection system redundancy and resource waste problems; and can perform long-distance signal transmission to meet the detection instrument location tracking, identity binding and data transmission functions. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a circuit principle block diagram of the multi-channel RFID reading and writing system of the present invention.

[0013] Figure 2 It is a circuit schematic diagram of the multiplexing circuit, communication conversion circuit and radio frequency antenna unit of the present invention.

[0014] Figure 3 It is a circuit schematic diagram of the antenna unit of the present invention. DETAILED DESCRIPTION

[0015] The following is a detailed description of an embodiment of the present invention in conjunction with the accompanying drawings. This embodiment is implemented on the premise of the technical solution of the present invention, and a detailed implementation method and a specific operation process are given, but the protection scope of the present invention is not limited to the following embodiment.

[0016] It should be noted that, in the description of the present invention, relational terms such as “first” and “second” are merely used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations.

[0017] In the description of the present invention, unless otherwise clearly specified and limited, the terms "connected" and "connection" that may appear should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0018] like Figure 1 As shown, the multi-channel RFID reading and writing system applied to the immune detection module of the present invention includes a central processing unit, the central processing unit adopts an STM32 single-chip microcomputer (MCU), a first universal synchronous / asynchronous serial transceiver interface (USART1) of the central processing unit is connected to a host computer through a MAX3232 transceiver, a second universal synchronous / asynchronous serial transceiver interface (USART2) of the central processing unit is connected to an input end of a multiplexing circuit, a general programmable I / O port (GPIO) of the central processing unit is connected to a control end of the multiplexing circuit; and an output end of the multiplexing circuit is connected to a radio frequency antenna unit via a communication conversion circuit.

[0019] The power supply adopts DC24V power supply, which supplies power to the central processing unit through 5 power converter and 3.3V power converter; the central processing unit I / O is connected with running indicator light, error indicator light and buzzer.

[0020] Advantageously or exemplarily, Figure 2 As shown, the multiplexing circuit includes a plurality of MOS tubes Qn (Q1\Q2\Q3\Q4\Q5), the source of each of the MOS tubes is respectively connected to the second universal synchronous / asynchronous serial transceiver interface (USART2) of the central processing unit, the gate of each MOS tube is respectively connected to the general programmable I / O port (GPIO) of the central processing unit, and the drain of each MOS tube is respectively connected to the radio frequency antenna unit via the communication conversion circuit.

[0021] Advantageously or exemplarily, the communication conversion circuit is composed of a first full-duplex transceiver (RS422) and a second full-duplex transceiver (RS422) connected in series.

[0022] Advantageously or exemplarily, Figure 2 As shown, the radio frequency antenna unit includes multiple antenna units with the same structure, and this embodiment includes five antenna units with the same structure.

[0023] Advantageously or exemplarily, Figure 2 , 3As shown, the antenna unit is composed of a radio frequency chip (FM17622) and a receiving circuit 1, a transmitting circuit 2, an impedance matching circuit 3 and a radio frequency antenna 4.

[0024] The receiving circuit 1 is composed of resistors R4, R5 and capacitors C9, C10; one end of the resistor R5 is connected to the internal reference voltage VMID of the RF chip (FM17622), and is connected to the ground GND through the capacitor C9; the other end of the resistor R5 is connected to the RF input terminal RX of the RF chip (FM17622), and is connected to one end of the capacitor C10 through the resistor R4.

[0025] The transmitting circuit 2 is composed of inductors L1, L2 and capacitors C11, C12; the capacitors C11 and C12 form a series circuit, one end of the capacitor C11 is respectively connected to the first end of the inductor L1 and the other end of the capacitor C10, and the second end of the inductor L1 is connected to the second transmitting output terminal TX2 of the radio frequency chip (FM17622); the connection point of the capacitor C11 and the capacitor C12 is connected to the ground GND; the capacitor C12 is connected to the first end of the inductor L2, and the second end of the inductor L2 is connected to the first transmitting output terminal TX1 of the radio frequency chip (FM17622); the inductors L1, L2 and the capacitors C11, C12 form a low-pass filter.

[0026] The impedance matching circuit 3 is composed of capacitors C1, C2, C3, C4, C5, C6, C7, and C8; the capacitors C1 and C7 form a first capacitor parallel circuit, the capacitors C2 and C8 form a second capacitor parallel circuit, the capacitors C3 and C4 form a first capacitor series circuit, and the capacitors C5 and C6 form a second capacitor series circuit; one end of the first capacitor parallel circuit is connected to the first end of the inductor L1, and one end of the second capacitor parallel circuit is connected to the first end of the inductor L2; the first capacitor series circuit and the second capacitor series circuit are respectively connected between the other ends of the first capacitor parallel circuit and the second capacitor parallel circuit; the connection point of capacitor C3 and capacitor C4 and the connection point of capacitor C5 and capacitor C6 are respectively connected to the ground GND.

[0027] The radio frequency antenna 4 is composed of two rectangular coils 4.1 and 4.2 connected in series and resistors R1, R2, and R3; one end of the two rectangular coils 4.1 and 4.2 connected in series is connected to the first capacitor parallel circuit through the resistor R1, and the other end of the two rectangular coils 4.1 and 4.2 connected in series is connected to the second capacitor parallel circuit through the resistor R3, and the connection point of the two rectangular coils connected in series is connected to the ground GND through the resistor R3; the resistors R1, R2, and R3 act as differential antenna connections.

[0028] In actual application, the radius of each rectangular coil 4.1, 4.2 is usually half of the detection distance; each antenna unit can perform different antenna matching circuit designs and RF antenna designs according to the different detection positions of the antenna and the corresponding detection distance requirements; the inductance and capacitance parameters of the two rectangular coils 4.1, 4.2 connected in series are measured by a bridge, and a spectrum analyzer is used to perform 50Ω impedance matching at a set frequency. The matching capacitor needs to be selected according to the parameters of the two rectangular coils 4.1, 4.2 connected in series so that the standing wave ratio reaches 1.2 to 1.5 to achieve the best antenna power transmission parameters.

[0029] The host computer selects to open the corresponding MOS tube Qn (Q1\Q2\Q3\Q4\Q5) controlled by the GPIO circuit according to the sample detection position and antenna unit number in the immune module, and then the serial port reads and writes the tag data according to the program to send instructions, and closes the MOS tube after completing the reading and writing.

[0030] The working process of the present invention is briefly described as follows: 1. The system is initialized and waits for receiving command data information from the host computer; 2. Data detection: detect whether the command sent by the host computer is correct (including frame header, frame tail, data length and check byte), and record which RF antenna unit is read / written and the number of blocks read / written.

[0031] 3. The multiplexing circuit switches the MOS tube of a single antenna loop through Gpio according to the instructions of the data frame.

[0032] 4. Card reading and writing operations: Card reading operations include: turning on the antenna, radio frequency initialization, card search, anti-collision, card selection, key verification and card reading and writing operation procedures.

[0033] Finally, it should be emphasized that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions recorded in the aforementioned embodiments without creative work, or replace some of the technical features therein with equivalents. Therefore, any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A multi-channel RFID reading and writing system applied to an immune detection module, characterized in that: It includes a central processing unit, wherein a first universal synchronous / asynchronous serial transceiver interface of the central processing unit is connected to a host computer through a transceiver, a second universal synchronous / asynchronous serial transceiver interface of the central processing unit is connected to an input end of a multiplexing circuit, and a universal programmable I / O port of the central processing unit is connected to a control end of the multiplexing circuit; The output end of the multiplexing circuit is connected to the radio frequency antenna unit via the communication conversion circuit.

2. The multi-channel RFID reading and writing system applied to the immune detection module according to claim 1 is characterized in that: The multiplexing circuit includes multiple MOS tubes, the source of each MOS tube is respectively connected to the second universal synchronous / asynchronous serial transceiver interface of the central processing unit, the gate of each MOS tube is respectively connected to the universal programmable I / O port of the central processing unit, and the drain of each MOS tube is respectively connected to the radio frequency antenna unit via the communication conversion circuit.

3. The multi-channel RFID reading and writing system applied to the immune detection module according to claim 1 or 2, characterized in that: The communication conversion circuit is composed of a first full-duplex transceiver and a second full-duplex transceiver connected in series.

4. The multi-channel RFID reading and writing system applied to the immune detection module according to claim 1 or 2, characterized in that: The radio frequency antenna unit comprises a plurality of antenna units with the same structure, and the antenna unit is composed of a radio frequency chip and a receiving circuit (1), a transmitting circuit (2), an impedance matching circuit (2) and an antenna (4).

5. The multi-channel RFID reading and writing system applied to the immune detection module according to claim 4 is characterized in that: The receiving circuit (1) is composed of resistors R4 and R5 and capacitors C9 and C10; one end of the resistor R5 is connected to VMID and connected to ground GND through the capacitor C9; the other end of the resistor R5 is connected to RX and connected to one end of the capacitor C10 through the resistor R4; The transmitting circuit (2) is composed of inductors L1, L2 and capacitors C11, C12; the capacitors C11, C12 form a series circuit, one end of the capacitor C11 is respectively connected to the first end of the inductor L1 and the other end of the capacitor C10, and the second end of the inductor L1 is connected to TX2; the connection point of the capacitor C11 and the capacitor C12 is connected to the ground GND; the capacitor C12 is connected to the first end of the inductor L2, and the second end of the inductor L2 is connected to TX1; the inductors L1, L2 and the capacitors C11, C12 form a low-pass filter; The impedance matching circuit (3) is composed of capacitors C1, C2, C3, C4, C5, C6, C7, and C8; the capacitors C1 and C7 form a first capacitor parallel circuit, the capacitors C2 and C8 form a second capacitor parallel circuit, the capacitors C3 and C4 form a first capacitor series circuit, and the capacitors C5 and C6 form a second capacitor series circuit; one end of the first capacitor parallel circuit is connected to the first end of the inductor L1, and one end of the second capacitor parallel circuit is connected to the first end of the inductor L2; the first capacitor series circuit and the second capacitor series circuit are respectively connected between the other ends of the first capacitor parallel circuit and the second capacitor parallel circuit; the connection point between the capacitor C3 and the capacitor C4 and the connection point between the capacitor C5 and the capacitor C6 are respectively connected to the ground GND; The antenna (4) is composed of two rectangular coils connected in series and resistors R1, R2, and R3; one end of the two rectangular coils connected in series is connected to a first capacitor parallel circuit via the resistor R1, the other end of the two rectangular coils connected in series is connected to a second capacitor parallel circuit via the resistor R3, and the connection point of the two rectangular coils connected in series is connected to a ground GND via the resistor R3; R1, R2, and R3 function as differential antenna connections.

6. The multi-channel RFID reading and writing system applied to the immune detection module according to claim 5, characterized in that: The radius of each rectangular coil is half of the detection distance.

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