Multi-channel RFID reader-writer communication control module

Abstract

The invention discloses a multi-channel RFID reader-writer communication control module which comprises an RS232 communication unit, a single-chip microcomputer U1, an alarm unit and a plurality of level conversion RS422 communication units. A communication interface of the RS232 communication unit is in communication connection with the industrial personal computer and the single-chip microcomputer U1. The single-chip microcomputer U1 is respectively connected with a plurality of level conversion RS422 communication units through a synchronous / asynchronous transceiver interface and a chip selection signal interface. The communication rate and the anti-interference capability of long-distance communication are improved, the layout convenience and miniaturization design of the RFID reader-writer in equipment are improved, one-to-one directional communication between the communication control module of the multi-channel RFID reader-writer and the RFID reader-writer is realized, the data accuracy of the RFID reader-writer of a specified channel is ensured, and crosstalk between the channels is reduced. Meanwhile, communication with a plurality of channel RFID reader-writers is carried out under the control of one single-chip microcomputer, a communication structure of cascade connection of a plurality of CAN nodes is reduced, the CAN nodes of the whole machine are few, and the efficiency of integrated processing of data information by the single-chip microcomputer is improved.

Description

Technical Field

[0001] The invention relates to an RFID reader / writer, and in particular to a multi-channel RFID reader / writer communication control module. Background Art

[0002] At present, most of the test kits in the medical IVD (In Vitro Diagnosis) industry use paper QR code labels or RFID electronic tags to read and identify the test kit information. With the development and popularization of technology, RFID readers have gradually replaced barcode scanners.

[0003] When RFID tags are applied in multiple locations on a medical IVD device, multiple RFID readers are required. Each RFID reader needs to integrate a single-chip microcomputer U1 control unit, which increases manufacturing costs and size. At the same time, when RFID electronic tags are used in multiple locations, one RFID reader corresponds to multiple RFID antennas, the communication distance is short, and it is susceptible to interference in the complex electrical environment of the medical device, and the RFID reading and writing success rate is low. Summary of the invention

[0004] In view of this, the present invention provides a multi-channel RFID reader communication control module to reduce manufacturing costs and improve data communication rate and anti-interference capability.

[0005] To achieve the above object, the present invention adopts the following technical solutions: The multi-channel RFID reader communication control module of the present invention comprises an RS232 communication unit, a single chip microcomputer U1, an alarm unit and a plurality of level conversion RS422 communication units; The RS232 communication unit communication interface is respectively connected to the industrial computer and the single-chip computer U1 for communication, and is used to convert the RS232 signal from the industrial computer into a TTL signal and send it to the single-chip computer U1, and convert the TTL signal from the single-chip computer U1 into an RS232 signal and send it to the industrial computer; The universal synchronous / asynchronous receiver / transmitter interface and the chip select signal interface of the single-chip computer U1 are respectively connected to a plurality of the level conversion RS422 communication units, and are used to enable the corresponding chip select signal interface and disable other chip select signal interfaces according to the instructions sent by the industrial computer, so as to ensure that the enabled channel signal data is accurate and not interfered by other level conversion RS422 communication units; realize data interaction with the corresponding level conversion RS422 communication unit through the universal synchronous / asynchronous receiver / transmitter interface; and at the same time, enable the internal timer to determine whether the enabled chip select signal interface completes the corresponding instruction within the specified time, and send the command execution result to the industrial computer; The level conversion RS422 communication unit comprises a level conversion unit and an RS422 full-duplex communication unit; the level conversion unit receives a chip selection signal of a single-chip microcomputer U1 and opens a corresponding enable channel, synchronously sends and receives a TTL signal sent by the single-chip microcomputer U1, and realizes interactive communication between a universal synchronous / asynchronous receiver and transmitter signal USART of the single-chip microcomputer U1 and the RS422 full-duplex communication unit; the universal synchronous / asynchronous receiver and transmitter are expanded, and a one-control-many communication application is realized, thereby improving the utilization rate; The RS422 full-duplex communication unit includes an RS422 full-duplex transceiver, which converts the logic level signal converted by the level conversion unit into a differential signal and sends it to the RFID reader, and converts the differential signal from the RFID reader into a logic level signal and sends it to the single-chip microcomputer U1, so as to realize full-duplex communication; improve the communication rate and the anti-interference ability of long-distance communication, improve the convenience and miniaturization design of the layout of the RFID reader in the equipment, realize the one-to-one directional communication between the multi-channel RFID reader communication control module and the RFID reader, ensure the accuracy of the RFID reader data of the specified channel, and reduce the crosstalk between channels; The control input terminal of the alarm unit is connected to the control terminal IO of the single chip microcomputer U1, and is used to receive the control signal output by the single chip microcomputer U1, and drive the indicator to issue a working status prompt of the RFID reader.

[0006] Furthermore, the RS232 communication unit includes a level conversion chip U4 (MAX3232), an interface J3 and an interface J4; both interfaces J3 and J4 can be connected to an industrial computer; interface J3 is used by the industrial computer to power the multi-channel RFID reader communication control module and communicate with it, and interface J4 is used to communicate with the industrial computer.

[0007] Further, the level conversion RS422 communication unit is two, including a first channel level conversion RS422 communication unit and a second channel level conversion RS422 communication unit; The first channel level conversion RS422 communication unit includes a first level conversion unit and a first RS422 full-duplex communication unit; the second channel level conversion RS422 communication unit includes a second level conversion unit and a second RS422 full-duplex communication unit; The first level conversion unit is composed of MOS tubes Q1, Q2 and resistors R1, R2, R3, R4, R5; the second channel level conversion RS422 communication unit is composed of MOS tubes Q3, Q4 and resistors R1, R2, R6, R7, R8; The high potential ends of R1, R2, R3, R4, and R5 are connected to the power supply VCC, and the low potential end of the resistor R4 is connected to the drain of the MOS tube Q1; the gates of the MOS tubes Q1 and Q2, and the low potential end of the resistor R3 are connected to the chip select signal interface CS1 of the single-chip computer U1; the source of the MOS tube Q1, the low potential end of R1, and the source of the MOS tube Q3 are connected to the receiving end (USART1_RX) of the universal synchronous / asynchronous receiver and transmitter interface of the single-chip computer U1; the drain of the MOS tube Q2 is connected to the low potential end of R5; the source of the MOS tube Q2 is connected to the low potential end of the resistor R2, the source of the MOS tube Q4, and the transmitting end (USART1_TX) of the universal synchronous / asynchronous receiver and transmitter interface of the single-chip computer U1; The high potential ends of the resistors R6, R7, and R8 are connected to the power supply VCC, and the drain of the MOS tube Q3 is connected to the low potential end of the resistor R7; the gates of the MOS tubes Q3 and Q4, and the low potential end of the resistor R6 are connected to the signal selection interface CS2 of the single chip computer U1; the drain of the MOS tube Q4 is connected to the low potential end of the resistor R8; The first RS422 full-duplex communication unit is composed of a full-duplex transceiver U2 (chip model: SIT3490), resistors R9, R10, and an RFID reader interface J1; the resistor R10 is connected between DI_Z and DI_Y of the full-duplex transceiver U2, and connected to the RFID reader interface J1; the resistor R9 is connected between RO_A and RO_B of the full-duplex transceiver U2, and connected to the RFID reader interface J1; the differential signal input and output of the full-duplex transceiver U2 are connected in parallel with the data sending end and data receiving end of the RFID reader interface J1, and data sending and receiving do not affect each other, thereby realizing full-duplex communication; The second channel RS422 full-duplex communication unit is composed of a full-duplex transceiver U3 (chip model: SIT3490), resistors R11, R12, and an RFID reader interface J2; the resistor R12 is connected between DI_Z and DI_Y of the full-duplex transceiver U3, and connected to the RFID reader interface J2; the resistor R11 is connected between RO_A and RO_B of the full-duplex transceiver U3, and connected to the RFID reader interface J2; the differential signal input and output of the full-duplex transceiver U3 are connected in parallel with the data sending end and data receiving end of the RFID reader interface J2, and data sending and receiving do not affect each other, thereby realizing full-duplex communication.

[0008] Preferably, the alarm unit is composed of a transistor Q5, a resistor R13, a resistor R16, and an indicator; the base of the transistor Q5 is connected to the output IO port of the single-chip computer U1 through the resistor R13; the anode of the indicator is connected to the power supply VCC, and the cathode of the indicator is connected to the collector of the transistor Q5 through the resistor R16; the emitter of the transistor Q5 is grounded; of course, the indicator can be a buzzer and / or an indicator light.

[0009] The present invention improves the communication rate and the anti-interference ability of long-distance communication, improves the convenience and miniaturization design of the layout of the RFID reader in the device, realizes the one-to-one directional communication between the multi-channel RFID reader communication control module and the RFID reader, ensures the accuracy of the RFID reader data of the specified channel, and reduces the crosstalk between channels. At the same time, under the control of a single-chip microcomputer, it communicates with multiple channel RFID readers, reduces the communication structure of multiple CAN node cascades, has fewer CAN nodes in the whole machine, and improves the efficiency of single-chip microcomputer integrated processing of data information. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is a circuit schematic diagram of the present invention.

[0011] Figure 2 It is an application block diagram of the present invention. DETAILED DESCRIPTION

[0012] 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.

[0013] 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.

[0014] 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.

[0015] like Figure 1As shown, the multi-channel RFID reader communication control module of the present invention includes an RS232 communication unit 1, a single-chip microcomputer U1, an alarm unit 4 and two level conversion RS422 communication units; The communication interface of the RS232 communication unit 1 is respectively connected to the industrial computer and the single-chip computer U1 for communication, and is used to convert the RS232 signal from the industrial computer into a TTL signal and send it to the single-chip computer U1, and convert the TTL signal from the single-chip computer U1 into an RS232 signal and send it to the industrial computer; The universal synchronous / asynchronous receiver / transmitter interface and chip select signal interface of the single-chip computer U1 are respectively connected to several level conversion RS422 communication units, and are used to enable the corresponding chip select signal interface and disable other chip select signal interfaces according to the instructions sent by the industrial computer, so as to ensure that the enabled channel signal data is accurate and not interfered by other level conversion RS422 communication units; realize data interaction through the universal synchronous / asynchronous receiver / transmitter interface and the corresponding level conversion RS422 communication unit; at the same time, enable the internal timer to determine whether the enabled chip select signal interface completes the corresponding instruction within the specified time, and send the command execution result to the industrial computer; The level conversion RS422 communication unit includes a level conversion unit and an RS422 full-duplex communication unit; the level conversion unit receives a chip selection signal of the single-chip microcomputer U1 and opens a corresponding enable channel, synchronously sends and receives a TTL signal sent by the single-chip microcomputer U1, and realizes interactive communication between the single-chip microcomputer U1 universal synchronous / asynchronous receiver and transmitter signal USART and the RS422 full-duplex communication unit; the universal synchronous / asynchronous receiver and transmitter are expanded, and a one-control-many communication application is realized, thereby improving the utilization rate; The RS422 full-duplex communication unit includes an RS422 full-duplex transceiver. The RS422 full-duplex transceiver converts the logic level signal converted by the level conversion unit into a differential signal and sends it to the RFID reader, and converts the differential signal from the RFID reader into a logic level signal and sends it to the single-chip microcomputer U1, thereby realizing full-duplex communication; improving the communication rate and the anti-interference ability of long-distance communication, improving the convenience and miniaturization design of the layout of the RFID reader in the equipment, realizing one-to-one directional communication between the multi-channel RFID reader communication control module and the RFID reader, ensuring the accuracy of the RFID reader data of the specified channel, and reducing the crosstalk between channels; The control input terminal of the alarm unit is connected to the control terminal IO of the single chip microcomputer U1, and is used to receive the control signal output by the single chip microcomputer U1, and drive the indicator to issue a working status prompt of the RFID reader.

[0016] Beneficially or exemplarily, the RS232 communication unit 1 includes a level conversion chip U4 (MAX3232), an interface J3 and an interface J4; both interfaces J3 and J4 can be connected to an industrial computer; interface J3 is used by the industrial computer to power the multi-channel RFID reader communication control module and communicate, and interface J4 is used for communication interaction with the industrial computer.

[0017] Advantageously or exemplarily, the two level conversion RS422 communication units are a first channel level conversion RS422 communication unit 2 and a second channel level conversion RS422 communication unit 3; The first channel level conversion RS422 communication unit 2 includes a first level conversion unit 2.1 and a first RS422 full-duplex communication unit 2.2; the second channel level conversion RS422 communication unit 3 includes a second level conversion unit 3.1 and a second RS422 full-duplex communication unit 3.2; The first level conversion unit 2.1 is composed of MOS tubes Q1, Q2 and resistors R1, R2, R3, R4, R5; the second channel level conversion RS422 communication unit 3 is composed of MOS tubes Q3, Q4 and resistors R1, R2, R6, R7, R8; The high potential ends of R1, R2, R3, R4 and R5 are connected to the power supply VCC, and the low potential end of the resistor R4 is connected to the drain of the MOS tube Q1; the gates of the MOS tubes Q1 and Q2, and the low potential end of the resistor R3 are connected to the chip select signal interface CS1 of the single-chip computer U1; the source of the MOS tube Q1, the low potential end of R1, and the source of the MOS tube Q3 are connected to the receiving end (USART1_RX) of the universal synchronous / asynchronous receiver and transmitter interface of the single-chip computer U1 for receiving serial data streams; the drain of the MOS tube Q2 is connected to the low potential end of R5; the source of the MOS tube Q2 is connected to the low potential end of the resistor R2, the source of the MOS tube Q4, and the transmitting end (USART1_TX) of the universal synchronous / asynchronous receiver and transmitter interface of the single-chip computer U1 for sending serial data streams; The high potential ends of resistors R6, R7, and R8 are connected to the power supply VCC, and the drain of MOS tube Q3 is connected to the low potential end of resistor R7; the gates of MOS tubes Q3 and Q4, and the low potential end of resistor R6 are connected to the signal selection interface CS2 of the single chip computer U1; the drain of MOS tube Q4 is connected to the low potential end of resistor R8; The first RS422 full-duplex communication unit 2.2 is composed of a full-duplex transceiver U2 (chip model: SIT3490), resistors R9, R10, and an RFID reader interface J1; resistor R10 is connected between DI_Z and DI_Y of the full-duplex transceiver U2, and connected to the RFID reader interface J1; resistor R9 is connected between RO_A and RO_B of the full-duplex transceiver U2, and connected to the RFID reader interface J1; the differential signal input and output of the full-duplex transceiver U2 are connected in parallel with the data sending end and data receiving end of the RFID reader interface J1, and data sending and receiving do not affect each other, thereby realizing full-duplex communication; The second channel RS422 full-duplex communication unit is composed of a full-duplex transceiver U3 (chip model: SIT3490), resistors R11, R12, and an RFID reader interface J2; resistor R12 is connected between DI_Z and DI_Y of the full-duplex transceiver U3, and connected to the RFID reader interface J2; resistor R11 is connected between RO_A and RO_B of the full-duplex transceiver U3, and connected to the RFID reader interface J2; the differential signal input and output of the full-duplex transceiver U3 are connected in parallel with the data sending end and data receiving end of the RFID reader interface J2, and data sending and receiving do not affect each other, thus achieving full-duplex communication.

[0018] Preferably, the alarm unit is composed of a transistor Q5, a resistor R13, a resistor R16, and a buzzer; the base of the transistor Q5 is connected to the IO port of the microcontroller U1 through the resistor R13; the anode of the buzzer is connected to the power supply VCC, and the cathode of the buzzer is connected to the collector of the transistor Q5 through the resistor R16; the emitter of the transistor Q5 is grounded.

[0019] like Figure 1 , 2 As shown, the working principle of the present invention is briefly described as follows: 1. When the operator selects reagent bottle A to load and scan through the display screen (human-computer interaction unit), the display screen human-computer interaction unit sends the corresponding command to the industrial computer, and the industrial computer sends the command signal to the RS232 communication unit 1 through the interface J3 of the RS232 communication unit 1. After the level conversion is performed by the level conversion chip U4 (dual-channel RS-232 transceiver, chip model: MAX3232), it is transmitted to the universal synchronous / asynchronous receiver and transmitter interface USART2_RX of the single-chip computer U1. The single-chip computer U1 sets the chip select interface CS1 end output to a high level. The gates of the MOS tubes Q1 and Q2 of a level conversion unit 2.1 are at a high level, the first channel level conversion RS422 communication unit 2 is enabled to work, and at the same time the timer of the single-chip microcomputer U1 is turned on to identify the set time limit of the RFID tag with the RFID reader, the chip select interface CS2 end output of the single-chip microcomputer U1 is set to a low level, and the second channel level conversion RS422 communication unit 3 is in a disabled state, ensuring that the signal of the second channel level conversion RS422 communication unit 3 will not interfere with the signal transmission and reception of the first channel level conversion RS422 communication unit 2.

[0020] The level conversion RS422 communication unit can be expanded to 4 channels or even more to improve the utilization rate of the universal synchronous / asynchronous receiver / transmitter interface USART of the microcontroller.

[0021] The microcontroller U1 processes and converts the received command and reads the card through the universal synchronous / asynchronous transceiver interface USART1_TX. When the signal is high, the source of the MOS tube Q2 is high-level cutoff, and the drain of the MOS tube Q2 is pulled up to the VCC level through the resistor R5. The 3rd pin DI input terminal of the full-duplex transceiver U2 (chip model: SIT3490) of the first RS422 full-duplex communication unit 2.2 inputs a high level, and the 5th and 6th pins of the full-duplex transceiver U2 are the in-phase and reverse output terminals of the driver respectively, and the Y terminal outputs a high level. The Z terminal outputs a low-level signal, thereby forming an output differential signal, improving the signal transmission distance and the signal's ability to resist interference in complex electromagnetic environment equipment. Resistor R10 is a matching resistor for differential signals. When the signal waveform quality is affected by stray capacitance and distance between communication lines, the influence can be eliminated by adjusting the resistance value of resistor R10 to obtain better signal quality. In the default state, the resistance value of resistor R10 is usually 120 ohms, and a differential signal matching resistor is also designed in the RFID reader circuit connected to the other end of interface J1. When the signal of the universal synchronous / asynchronous transceiver interface USART1_TX is low, the source of MOS tube Q2 is low-level and turned on, the drain of MOS tube Q2 is low-level, the 3rd pin DI input terminal of the full-duplex transceiver U2 is low-level, the 5th pin of the full-duplex transceiver U2 outputs a low level and the 6th pin outputs a high level.

[0022] When the RFID reader scans the RFID tag of reagent bottle A, the RFID reader is connected to the inverting input terminal of the 7th pin and the non-inverting input terminal of the 8th pin of the full-duplex transceiver U2 through the interface J1. The resistor R9 is a differential signal matching resistor, and its function is the same as that of the resistor R10. When the level of the 8th pin of the full-duplex transceiver U2 minus the level of the 7th pin of the full-duplex transceiver U2 is ≥ 200mV, that is, AB ≥ 200mV, the Ro terminal of the full-duplex transceiver U2 outputs a high level, the drain of the MOS tube Q1 of the level conversion circuit is a high level, and the source of the MOS tube Q1 is pulled up to VCC through the resistor R1, and the MO The source of S tube Q1 is also high level, MOS tube Q1 is cut off, and USART1_RX of the universal synchronous / asynchronous receiver and transmitter interface of the single-chip microcomputer U1 inputs a high level signal; when AB≤-200mV, the Ro end of the full-duplex transceiver U2 outputs a low level, the drain of MOS tube Q1 is low level, Q1 is cut off, and due to the action of the internal body diode of MOS tube Q1, the source of MOS tube Q1 is turned on through the internal body diode of MOS tube, and the source of MOS tube Q1 is clamped to a low level (0.7V), and the UASRT1_RX end of the universal synchronous / asynchronous receiver and transmitter interface of the single-chip microcomputer U1 inputs a low level signal.

[0023] When the single-chip computer U1 receives the tag information returned by the RFID reader, the IO port of the single-chip computer U1 push-pull outputs a high level at a fixed time, the base of the transistor Q5 of the alarm unit is at a high level, the transistor Q5 is turned on, and the buzzer B1 emits a "beep" sound, prompting the operator that the loading scan is successful, and then the IO port of U1 push-pull outputs a low level, the transistor Q5 is turned off, and the buzzer B1 is turned off.

[0024] After the microcontroller U1 successfully reads the RFID tag of the reagent bottle A, the reagent content information and the reagent quantity information in the bottle are sent to the RS232 communication unit 1 via the universal synchronous / asynchronous receiver and transmitter interface USART2_TX, and after level conversion by the level conversion chip U4, communication with the industrial computer is achieved through the interface J3.

[0025] When the RFID reading and writing is successful, the industrial computer will feed back the information to the display screen of the human-machine interaction unit through the network cable, and display the reagent information in the RFID tag and the remaining amount in the reagent bottle; it will prompt that the reagent bottle A has been loaded successfully, and realize the dual visual and auditory interaction with the alarm unit.

[0026] If the single-chip computer U1 does not receive the tag information returned by the RFID reader within the time set by the timer, the IO terminal of the single-chip computer U1 will output high-level and low-level signals three times in a short fixed periodic period, the transistor Q5 will be turned on and off three times, and the buzzer B1 will beep three times and then turn off to remind the operator that the RFID electronic tag has not been correctly identified.

[0027] The single-chip computer U1 sends the RFID tag recognition failure information to the RS232 communication unit 1 through the universal synchronous / asynchronous receiver and transmitter interface USART2_TX, and realizes communication with the industrial computer through the interface J3; the industrial computer feeds back the information to the interactive unit display screen through the network cable, and the display screen prompts that the card search for the reagent bottle location label has failed, realizing dual visual and auditory interaction with the alarm unit.

[0028] When the operator clicks on the display screen to unload the reagent bottle A, the display screen sends the current reagent bottle A remaining data information to the industrial computer via the network line, and the industrial computer transmits the information to the universal synchronous / asynchronous receiver and transmitter interface USART2_RX of the single-chip computer U1 through the RS232 communication unit 1. The single-chip computer U1 sets the chip select interface CS1 end output to a high level, and the gates of the MOS tubes Q1 and Q2 of the first channel level conversion unit are high, and the first channel level conversion RS422 communication unit 2 is enabled; at the same time, the timer of the single-chip computer U1 is turned on to set the time for the RFID reader to identify the RFID tag, and the chip select interface CS2 end and IO end outputs of the single-chip computer U1 are set to a low level, and the second channel level conversion RS422 communication unit is in a disabled state to ensure that the channel signal will not interfere with the signal transmission and reception of the first channel level conversion RS422 communication unit 2.

[0029] 2. When the operator selects reagent bottle B to load and scan through the display screen, the display screen human-computer interaction unit will send the corresponding instructions to the industrial computer. The industrial computer sends the command signal to RS232 communication unit 1 through the interface J3 of RS232 communication unit 1. After the level conversion is performed by the level conversion chip U4 (dual-channel RS-232 transceiver, chip model: MAX3232), it is transmitted to the universal synchronous / asynchronous receiver and transceiver interface USART2_RX of the microcontroller U1. The single-chip microcomputer U1 sets the chip select interface CS2 output to a high level, the gates of the MOS tubes Q3 and Q4 of the second channel level conversion unit are high, the second channel level conversion RS422 communication unit 3 is enabled, and the timer of the single-chip microcomputer U1 is turned on for setting the time for the RFID reader to identify the RFID tag; the chip select interface CS1 and IO outputs of the single-chip microcomputer U1 are set to a low level, and the first channel level conversion RS422 communication unit 2 is in a disabled state, ensuring that the first channel level conversion RS422 communication unit 2 signal will not interfere with the sending and receiving of the second channel level conversion RS422 communication unit 3 signal.

[0030] The single-chip microcomputer U1 processes and converts the received command and reads the card through the single-chip microcomputer's universal synchronous / asynchronous transceiver interface USART1_TX. When the signal is high, the source of the MOS tube Q4 is high-level cutoff, and the drain of the MOS tube Q4 is pulled up to the VCC level through the resistor R8. The 3rd pin DI input end of the full-duplex transceiver U3 (SIT3490 chip) of the second RS422 full-duplex communication unit 3.2 enters a high level. The 5th and 6th pins of the full-duplex transceiver U2 are the in-phase and reverse output ends of the driver respectively, and the Y end outputs High-level signal, Z-end outputs low-level signal, thus forming an output differential signal, improving the signal transmission distance and the signal's anti-interference ability in complex electromagnetic environment equipment; resistor R12 is a matching resistor for differential signals. When the signal waveform quality is affected by stray capacitance and distance between communication lines, the influence can be eliminated by adjusting the resistance value of the resistor to obtain better signal quality. In the default state, the resistance value of resistor R12 is usually 120 ohms, and a differential signal matching resistor is also designed in the RFID reader circuit at the other end connected to interface J2. When the signal of the universal synchronous / asynchronous transceiver interface USART1_TX is low, the source of MOS tube Q4 is low-level and turned on, the drain of MOS tube Q4 is low-level, the 3rd pin DI input terminal of the full-duplex transceiver U3 is low-level, the 5th pin of the full-duplex transceiver U3 outputs low-level, and the 6th pin outputs high-level.

[0031] When the RFID reader scans the RFID tag of the reagent bottle B, the RFID reader is connected to the inverting input terminal of the 7th pin and the non-inverting input terminal of the 8th pin of the full-duplex transceiver U3 through the interface J2. The resistor R11 is a differential signal matching resistor, and its function is the same as that of R12. When the level of the 8th pin of the full-duplex transceiver U3 minus the level of the 7th pin ≥ 200mV, that is, AB ≥ 200mV, the Ro terminal of the full-duplex transceiver U3 outputs a high level, the drain of the MOS tube Q3 of the second level conversion circuit is a high level, and the source of the MOS tube Q3 is pulled up to the resistor R1. VCC, the source of MOS tube Q3 is also high-level and cut off, and the universal synchronous / asynchronous receiver transceiver interface USART1_RX inputs a high-level signal; when AB≤-200mV, the Ro end of the full-duplex transceiver U3 outputs a low level, and the drain of MOS tube Q3 is low-level and cut off; due to the body diode in MOS tube Q3, the source of MOS tube Q3 is turned on through the body diode in MOS tube, and the source of MOS tube Q3 is clamped to a low level (0.7V), and the universal synchronous / asynchronous receiver transceiver interface UASRT1_RX inputs a low-level signal.

[0032] When the single-chip computer U1 receives the tag information returned by the RFID reader, the IO port of the single-chip computer U1 push-pull outputs a high level at a fixed time, the base of the transistor Q5 of the alarm unit is turned on at a high level, and the buzzer B1 emits a "beep" sound, prompting the operator that the loading scan is successful, and then the IO port of the single-chip computer U1 push-pull outputs a low level, the transistor Q5 is cut off, and the buzzer is turned off.

[0033] The single-chip computer U1 sends the successful reading information of the RFID tag of the reagent bottle B, the reagent content information, and the reagent quantity information in the bottle to the RS232 communication unit 1 through the universal synchronous / asynchronous transceiver interface USART2_TX, and realizes communication with the industrial computer through the interface J3. When the RFID reading and writing is successful, the industrial computer feeds back the information to the display screen through the network cable, displays the reagent information in the RFID tag and the remaining amount in the reagent bottle, and realizes the dual visual and auditory interaction with the alarm unit.

[0034] If the microcontroller U1 does not receive the tag information returned by the RFID reader within the time limit set by the timer, the IO terminal of the microcontroller U1 will output high-level and low-level signals three times at a short fixed periodic time, the transistor Q5 will be turned on and off three times periodically, and the buzzer B1 will be turned off after three "beeps" to remind the operator that the RFID electronic tag has not been correctly identified. The microcontroller U1 sends the RFID tag recognition failure information to the RS232 unit through the universal synchronous / asynchronous transceiver interface USART2_TX, and communicates with the industrial computer (controller) through the interface J3. The industrial computer feeds back the information to the display screen of the human-machine interaction unit, and the display screen prompts that the tag search at the position of the reagent bottle B has failed, realizing the dual visual and auditory interaction with the alarm unit.

[0035] When the operator clicks on the reagent bottle unloading scan through the display screen, the display screen sends the current reagent bottle remaining data information to the industrial computer via the network line, and the industrial computer sends the information to the RS232 communication unit 1, which is transmitted to the universal synchronous / asynchronous receiver and transmitter interface USART2_RX of the single-chip computer U1 via the interface J3. The single-chip computer U1 sets the chip select interface CS2 end output to a high level, and the gates of the MOS tubes Q3 and Q4 of the second channel level conversion unit are high, and the second channel level conversion RS422 communication unit 3 is enabled to work; at the same time, the timer of the single-chip computer U1 is turned on for the time setting of the RFID reader to identify the RFID tag, and the chip select interface CS1 end and IO end outputs of the single-chip computer U1 are set to a low level, and the first channel level conversion RS422 communication unit 2 is in a disabled state, and the first channel level conversion RS422 communication unit 2 signal will not interfere with the sending and receiving of the second channel level conversion RS422 communication unit 3 signal.

[0036] Note: The RFID tag of the reagent bottle contains the reagent content and the liquid packaging volume in the reagent bottle (newly activated reagent); after the first loading, the packaging volume in the reagent bottle will be displayed on the display screen, and the value will be automatically updated according to the equipment operation usage. When unloading, the current remaining volume needs to be written into the RFID tag. There are two benefits: first, it is convenient to replace the unused reagents with other similar instruments and equipment, so that the remaining information in the reagent bottle can be known in time; second, when the reagent bottle is used up and needs to be unloaded, the remaining volume is written as 0 in the tag, avoiding inaccurate detection results caused by the illegal injection of non-standard reagents into the reagent bottle.

[0037] Finally, it should be emphasized that the above are only preferred embodiments of the present invention and are 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 described 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 principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A multi-channel RFID reader communication control module, characterized in that: It includes RS232 communication unit, single chip microcomputer U1, alarm unit and several level conversion RS422 communication units; The RS232 communication unit communication interface is respectively connected to the industrial computer and the single-chip computer U1 for communication, and is used to convert the RS232 signal from the industrial computer into a TTL signal and send it to the single-chip computer U1, and convert the TTL signal from the single-chip computer U1 into an RS232 signal and send it to the industrial computer; The universal synchronous / asynchronous receiver / transmitter interface and the chip select signal interface of the single-chip computer U1 are respectively connected to a plurality of the level conversion RS422 communication units, and are used to enable the corresponding chip select signal interface and disable other chip select signal interfaces according to the instructions sent by the industrial computer; realize data interaction with the corresponding level conversion RS422 communication unit through the universal synchronous / asynchronous receiver / transmitter interface; and at the same time, enable the internal timer to determine whether the enabled chip select signal interface completes the corresponding instruction within the specified time, and send the command execution result to the industrial computer; A level conversion RS422 communication unit, comprising a level conversion unit and an RS422 full-duplex communication unit; the level conversion unit receives a chip select signal of the single-chip microcomputer U1 and opens a corresponding enable channel, synchronously sends and receives a TTL signal sent by the single-chip microcomputer U1, and realizes interactive communication between the single-chip microcomputer U1 universal synchronous / asynchronous receiver and transmitter signal and the RS422 full-duplex communication unit; The RS422 full-duplex communication unit includes an RS422 full-duplex transceiver, which converts the logic level signal converted by the level conversion unit into a differential signal and sends it to the RFID reader, and converts the differential signal from the RFID reader into a logic level signal and sends it to the single-chip microcomputer U1; The control input terminal of the alarm unit is connected to the control terminal of the single chip microcomputer U1, and is used to receive the control signal output by the single chip microcomputer U1, and drive the indicator to issue a working status prompt of the RFID reader.

2. The multi-channel RFID reader communication control module according to claim 1, characterized in that: The RS232 communication unit includes a level conversion chip U4, an interface J3 and an interface J4; both interfaces J3 and J4 can be connected to an industrial computer; interface J3 is used by the industrial computer to supply power to the multi-channel RFID reader communication control module and communicate with it, and interface J4 is used to communicate with the industrial computer.

3. The multi-channel RFID reader communication control module according to claim 1 or 2, characterized in that: The level conversion RS422 communication unit includes a first channel level conversion RS422 communication unit and a second channel level conversion RS422 communication unit; The first channel level conversion RS422 communication unit includes a first level conversion unit and a first RS422 full-duplex communication unit; the second channel level conversion RS422 communication unit includes a second level conversion unit and a second RS422 full-duplex communication unit; The first level conversion unit is composed of MOS tubes Q1, Q2 and resistors R1, R2, R3, R4, R5; the second channel level conversion RS422 communication unit is composed of MOS tubes Q3, Q4 and resistors R1, R2, R6, R7, R8; The high potential ends of R1, R2, R3, R4 and R5 are connected to the power supply VCC, and the low potential end of the resistor R4 is connected to the drain of the MOS tube Q1; the gates of the MOS tubes Q1 and Q2, and the low potential end of the resistor R3 are connected to the chip select signal interface CS1 of the single-chip computer U1; the source of the MOS tube Q1, the low potential end of R1, and the source of the MOS tube Q3 are connected to the receiving end of the universal synchronous / asynchronous receiver / transmitter interface of the single-chip computer U1; the drain of the MOS tube Q2 is connected to the low potential end of R5; the source of the MOS tube Q2 is connected to the low potential end of the resistor R2, the source of the MOS tube Q4, and the sending end of the universal synchronous / asynchronous receiver / transmitter interface of the single-chip computer U1; The high potential ends of the resistors R6, R7, and R8 are connected to the power supply VCC, and the drain of the MOS tube Q3 is connected to the low potential end of the resistor R7; the gates of the MOS tubes Q3 and Q4, and the low potential end of the resistor R6 are connected to the signal selection interface CS2 of the single chip computer U1; the drain of the MOS tube Q4 is connected to the low potential end of the resistor R8; The first RS422 full-duplex communication unit is composed of a full-duplex transceiver U2, resistors R9, R10, and an RFID reader interface J1; the resistor R10 is connected between DI_Z and DI_Y of the full-duplex transceiver U2, and connected to the RFID reader interface J1; the resistor R9 is connected between RO_A and RO_B of the full-duplex transceiver U2, and connected to the RFID reader interface J1; The second channel RS422 full-duplex communication unit is composed of a full-duplex transceiver U3, resistors R11, R12, and an RFID reader interface J2; the resistor R12 is connected between DI_Z and DI_Y of the full-duplex transceiver U3, and connected to the RFID reader interface J2; the resistor R11 is connected between RO_A and RO_B of the full-duplex transceiver U3, and connected to the RFID reader interface J2.

4. The multi-channel RFID reader-writer communication control module according to claim 1 or 2, characterized in that: The alarm unit is composed of a transistor Q5, a resistor R13, a resistor R16, and an indicator; the base of the transistor Q5 is connected to the output control terminal of the single-chip computer U1 through the resistor R13; the anode of the indicator is connected to the power supply VCC, and the cathode of the indicator is connected to the collector of the transistor Q5 through the resistor R16; the emitter of the transistor Q5 is grounded.

Images