DTU wireless data transmission terminal

Abstract

The utility model provides a DTU wireless data transmission terminal which is used for solving the technical problem that an existing industrial controller cannot achieve a wireless remote transmission function. The gas detector comprises a shell, a circuit board is arranged in the shell, a main control chip, an acquisition communication module and a 4G communication module are arranged on the circuit board, the main control chip is respectively connected with the acquisition communication module and the 4G communication module, the acquisition communication module is connected with a controller, the controller is connected with a plurality of gas detectors, and the gas detectors are connected with the 4G communication module. The 4G communication module is connected with the cloud platform and the mobile terminal through the base station, and the cloud platform is connected with the upper computer through a network. The utility model has the characteristics of stable performance, small volume, high cost performance and low cost, and is beneficial to the integration of user equipment and a system; the controller is powerful in function and strong in adaptability, can provide uploading schemes for various controllers, is strong in expandability, and can replace the small communication board according to requirements.

Description

Technical Field

[0001] The utility model relates to the technical field of data transmission terminals, in particular to a DTU wireless data transmission terminal. Background Art

[0002] With the development of the Internet of Things, the Internet of Things is not only increasingly used in small and micro places, but is also gradually expanding to the industrial field. The Industrial Internet of Things (IIoT) applies the Internet of Things technology to the industrial field, realizing the organic combination of materials, energy and information, which can help enterprises achieve digital transformation, improve production efficiency, reduce costs, and improve product quality.

[0003] In the field of smart security, gas detection controllers are commonly used control and collection equipment in the industrial field. They are responsible for collecting information collected by surrounding detectors and then displaying it on the main control panel for easy viewing by staff. However, staff need to go to the control room every time they check, which leads to low work efficiency. Efficient and convenient data collection and analysis are the problems currently faced by industrial enterprises. In addition, how to make efficient use of data after data collection? In the process of seeking reliable solutions, the Internet of Things cloud platform was born.

[0004] In order to meet the current needs of industrial gas detection controllers to quickly connect to the mainstream IoT platform in the market, DTU (Data Transfer Unit) devices are designed and developed to meet networking needs. DTU is used to process and transmit data and send data to the cloud. It is often used in monitoring, control, measurement, and remote computer room monitoring. The existing DTU is large in size and uses a metal shell, which is expensive. This application is small in size, 80*50*26mm, light in weight, no more than 1kg, and low in cost.

[0005] The invention patent with application number 202110562508.0 discloses a portable intelligent gas detection alarm based on data transmission by the Internet of Things, including: a gas detection module collects gas information of the gas; a real-time gas curve is displayed through a display; an alarm module calculates the alarm value according to the real-time gas curve and the preset alarm rules, and an alarm is issued according to the alarm value. The storage module stores gas information, real-time gas curves and alarm data; the positioning module determines the real-time position of the detection personnel during gas detection and the alarm position for alarming through the preset built-in positioning map and positioning chip; when the alarm module issues an alarm through the Internet of Things card, the gas information, the real-time position of the personnel and the alarm position are uploaded to the cloud platform; the above invention can quickly detect the concentration of multiple gases, temperature and humidity measurements and exceed the alarm; perform multi-directional gas alarms through the Internet of Things; detect multiple gases to protect the safety of enterprise personnel. However, the above invention is a stand-alone alarm instrument with wireless remote transmission and positioning functions, which is relatively expensive. Utility Model Content

[0006] In view of the technical problem that existing industrial controllers cannot realize wireless remote transmission function, the utility model proposes a DTU wireless data transmission terminal to provide remote transmission function for industrial controllers. It does not collect any gas, but only collects information in the controller and uploads it. It can not only upload the information of the controller to the cloud platform, but also use 4G to realize telephone and SMS alarm functions.

[0007] In order to achieve the above-mentioned purpose, the technical solution of the utility model is implemented as follows: a DTU wireless data transmission terminal comprises a shell, a circuit board is arranged in the shell, a main control chip, an acquisition communication module and a 4G communication module are arranged on the circuit board, the main control chip is respectively connected to the acquisition communication module and the 4G communication module, the acquisition communication module is connected to the controller, the controller is connected to multiple gas detectors, the 4G communication module is respectively connected to the cloud platform and the mobile terminal through the base station, and the cloud platform is connected to the host computer through the network.

[0008] Preferably, the controller is a combustible gas industrial controller, and the gas detector is a methane gas detector.

[0009] Preferably, the main control chip is also connected to a reset circuit, an LED indication module, a power management module, and a parameter burning module. The reset circuit is used to reset the registers and memory in the main control chip. The power management module converts the input voltage into a voltage used by the main control chip. The parameter burning module is used for the host computer to write configurable information to the main control chip. The LED indication module is arranged on the housing.

[0010] Preferably, the main control chip is an MCU, and the MCU has 128K flash and 20K RAM.

[0011] Preferably, the reset circuit includes a resistor R26 and a capacitor C15 connected in series, the other end of the resistor R26 is connected to a 3.3V power supply, the other end of the capacitor C15 is grounded, and the midpoint of the connection between the resistor R26 and the capacitor C15 is connected to the NRST pin of the MCU of the main control chip.

[0012] Preferably, the LED indication module includes a red LED light, a green LED light and a yellow LED light, the red LED light indicates the network status, the green LED light represents the collection status, and the yellow LED light represents the communication status; one end of the red LED light, the green LED light and the yellow LED light are respectively connected to the control pin of the MCU, and the other ends of the red LED light, the green LED light and the yellow LED light are all connected to the 3.3V power supply through resistors.

[0013] Preferably, the acquisition mode of the acquisition communication module is RS485 mode or TTL mode, one end of the RS485 mode or TTL mode circuit is connected to the control pin of the MCU, and the other end of the RS485 mode or TTL mode circuit is connected to the output end of the controller; the power management module is a level conversion circuit, and the level conversion circuit converts the input 24V voltage into a voltage value used by the MCU and 4G communication module.

[0014] Preferably, the parameter burning module includes an insertion terminal J3, which is a 6-PIN-2.54 pitch male terminal; one end of the insertion terminal J3 is connected to the MCU and the other end is connected to the serial port tool; the 4G communication module is a Quectel module, which is connected to the 3.3V power supply and the MCU of the main control chip through the plug-in terminal J1.

[0015] Preferably, the 4G communication module is respectively connected to the SIM card slot module, the serial port level matching circuit, the plug-in terminal J1, the reset module and the power module, and the serial port level matching circuit is connected to the MCU.

[0016] Preferably, the reset module includes a resistor R37 and a capacitor C31, one end of the resistor R37 and the capacitor C31 are both connected to the RESET pin of the Quectel module, the other end of the capacitor C31 is grounded, and the other end of the resistor R37 is connected to the MCU; the power module includes a switching regulator, which converts the input voltage into a 3.8V voltage used by the 4G communication module; the SIM card slot module is a flip-top card socket, which includes a cover and a base, the cover and the base are detachably connected, and the base is plugged into the SIM card; the serial port level matching circuit converts the serial port level of the MCU and the serial port level of the 4G communication module to a matching state.

[0017] Compared with the prior art, the utility model has the following beneficial effects: the utility model can upload the information of the controller to the cloud platform, and can realize the alarm prompt of the mobile phone; it protects the safety of the staff's work. The utility model is applicable to a wide range of scenarios, and supports RS485 and TTL acquisition communication methods; the utility model has a wide input voltage range and is compatible with the controller output voltage of 4-36V; the utility model has the characteristics of stable performance, small size, high cost performance, low cost, and is conducive to the integration of user equipment and systems. The utility model is powerful and adaptable, and can provide upload solutions for a variety of controllers. It has strong scalability, and the communication board can be replaced according to needs. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0019] Figure 1 This is a principle block diagram of the utility model.

[0020] Figure 2 This is a connection diagram for the application of the utility model.

[0021] Figure 3 It is a structural diagram of the MCU of the present utility model.

[0022] Figure 4 It is a circuit diagram of the reset circuit of the utility model.

[0023] Figure 5 This is a circuit diagram of the LED indicator module of the present utility model.

[0024] Figure 6 This is a structural diagram of the acquisition communication module of the present utility model.

[0025] Figure 7 This is a circuit diagram of the power management module of the utility model.

[0026] Figure 8 The utility model is a circuit diagram of the parameter burning module.

[0027] Fig. 9 This is a connection diagram of the 4G communication module interface of the present utility model.

[0028] Fig.10 This is a circuit diagram of the 4G communication module of the present utility model.

[0029] Fig.11This is a circuit diagram of the reset module of the 4G communication module of the present utility model.

[0030] Fig.12 This is a circuit diagram of the power module of the 4G communication module of the present utility model.

[0031] Fig.13 This is a circuit diagram of the SIM card slot module of the 4G communication module of the present utility model.

[0032] Fig.14 This is a circuit diagram of a serial port level matching circuit of a 4G communication module of the present utility model.

[0033] In the figure, 1 is the cloud platform, 2 is the host computer, 3 is the base station, 4 is the mobile terminal, 5 is the DTU wireless data transmission terminal, 6 is the controller, and 7 is the gas detector. DETAILED DESCRIPTION

[0034] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0035] like Figure 1 As shown, a DTU wireless data transmission terminal includes a housing, a circuit board is arranged in the housing, a main control chip, a collection communication module and a 4G communication module are arranged on the circuit board, and the main control chip is connected to the collection communication module and the 4G communication module respectively, as shown in FIG. Figure 2 As shown, the acquisition communication module is connected to the controller 6, the controller 6 is connected to multiple gas detectors 7, the 4G communication module is connected to the cloud platform 1 and the mobile terminal 4 respectively through the base station 3, and the cloud platform 1 is connected to the host computer 2 through the network. The function of the acquisition communication module is to collect controller information, and the alarm information or fault information in the controller 6 can be understood. The function of the 4G communication module is to realize the remote transmission function, positioning function and voice dialing function. The controller 6 is a combustible gas industrial controller KB100, which can be connected to 8 gas detectors. The gas detector 7 is a methane gas detector with a model of GTQ-BS03.

[0036] like Figure 2As shown, the controller 6 collects the information of the gas detector 7 by wired means and displays it on the display screen. After the DTU wireless data transmission terminal 5 of the present application collects the information collected by the gas detector 7 in the controller 6 through the collection communication module, the 4G communication module uses 4G-TCP communication to send the data to the cloud platform 1 through the operator's base station 3. The information of the cloud platform 1 can be displayed on the host computer 2, and the phone call or text message can be sent to the mobile terminal 4 through the operator's base station 3.

[0037] The main control chip is also connected to the reset circuit, LED indicator module, power management module, and parameter burning module. The reset circuit is used to reset the registers and memories in the main control chip, which can protect the circuit. When the circuit fails or is abnormal, the circuit can be restored to the initial state to avoid circuit damage or further failure, while ensuring the normal startup of the system. The power management module converts the input voltage into the voltage used by the main control chip and each module to ensure the normal power supply of each module. The parameter burning module can use the local host computer to write the device number, server IP and PORT to the DTU, thereby writing configurable information. The LED indicator module is set on the housing to indicate the operating status of the entire device.

[0038] The main control chip is MCU. The MCU is STMicroelectronics STM32L071RBT6, which is powerful, resource-rich, and robust. It has 128K flash and 20K RAM, leaving enough space for expansion functions, such as Figure 3 The VDD pin, VDDIO2 pin, and VDDA pin of the MCU are all connected to the 3.3V power supply, and the VSSA pin and VSS pin of the MCU are all grounded. The pins with marked information are used pins, which are connected to pins with the same electrical properties through wires for control or acquisition; the remaining unmarked pins are not used.

[0039] The reset circuit is used to initialize all registers, register groups, internal memory, etc. of the MCU to the default state, thereby ensuring that the MCU's single-chip microcomputer system is in a controllable state, such as Figure 4 As shown. The reset circuit includes a resistor R26 and a capacitor C15 connected in series. The other end of the resistor R26 is connected to the 3.3V power supply, the other end of the capacitor C15 is grounded, and the midpoint of the connection between the resistor R26 and the capacitor C15 is connected to the NRST pin of the MCU. At the moment of power-on, the charging current of the capacitor C15 is the largest, the capacitor C15 is equivalent to a short circuit, the NRST end is a high level, and it is automatically reset; when the voltage across the capacitor C15 reaches the power supply voltage, the capacitor charging current is zero, the capacitor C15 is equivalent to an open circuit, the NRST end is a low level, and the program runs normally.

[0040] The LED indicator module consists of three LED lights, namely red LED light, green LED light and yellow LED light, to indicate the operating status of the DTU device. Red represents the network status, green represents the collection status, and yellow represents the communication status. Figure 5 As shown. One end of the red LED, green LED and yellow LED are connected to the MCU's PA10, PA9 and PA8 pins respectively, the other end of the red LED is connected to the 3.3V power supply through resistor R16, the other end of the green LED is connected to the 3.3V power supply through resistor R17, and the other end of the yellow LED is connected to the 3.3V power supply through resistor R18. The MCU uses the three pins PA8, PA9 and PA10 to control the on and off of the three LEDs.

[0041] The function of the acquisition communication module is to acquire information from the controller 6. The acquisition method is RS485 or TTL, both of which are supported by the module, and the acquired information is processed. When using RS485 to acquire data, the acquisition chip uses Intel's ISL83072EIBZA-T and is packaged in SOP-8. The Sop-8 package is smaller than the traditional DIP package, saving space and increasing line density. 8 is the number of pins for this chip, such as Figure 6 As shown. The R pin of the acquisition chip is connected to the PA3 pin of the MCU, and the MCU receives data information from the acquisition chip. The RE pin and GND pin of the acquisition chip are both grounded. The DE pin of the acquisition chip is connected to the PA1 pin of the MCU to enable the acquisition chip. The D pin of the acquisition chip is connected to the PA2 pin of the MCU, and the MCU sends data information to the acquisition chip. The VCC pin of the acquisition chip is respectively connected to the 3V power supply and one end of the capacitor C1. The other end of the capacitor C1 is grounded. The capacitor C1 is a filter capacitor, which makes the power supply more stable and filters out clutter. The A pin of the acquisition chip is respectively connected to one end of the resistor R5 and one end of the resistor R8. The B pin of the acquisition chip is respectively connected to the other end of the resistor R5 and one end of the resistor R4. The other end of the resistor R8 and the other end of the resistor R4 are respectively connected to the output end of the controller 6. The functions of the resistors R8 and R4 are impedance matching and current limiting, and the function of the resistor R5 is impedance matching. When TTL communication is used for data acquisition, remove the acquisition chip U2 and resistors R5, R8, and R4, that is, directly connect one end of the resistor R14 to the PA3 pin of the MCU, connect one end of the resistor R13 to the PA2 pin of the MCU, and connect the other ends of the resistors R13 and R14 as two input ends to the output end of the controller 6 respectively. When 485 communication is used, remove the resistors R13 and R14.

[0042] The power management module is a level conversion circuit, which converts the input 24V voltage into the voltage value used by MCU, 4G communication module and other devices. The power chip model MP9442 has a continuous wide operating input voltage range of 4V to 36V. It is a high-frequency synchronous rectification step-down switch mode converter with built-in power MOSFET, providing a very compact solution. It can achieve a continuous output current of 2A in a wide input range and has excellent load and line regulation. Figure 7 As shown. The power management module supplies power to each module of the circuit and provides 3.3V voltage to the MCU. P1 is the external output voltage and communication pins A and B. Among them, the function of fuse F1 is to prevent excessive current, the function of diode D1 is to prevent reverse connection of power supply, chip U1 is the power chip, the function of capacitors C3-C10 is voltage stabilization and filtering, the function of resistor R3 is to enable the power chip, the function of resistor R6 is to supply power to the PG pin, the functions of resistors R7, R12, R10 and R11 are to adjust the output voltage, capacitor C11 is a filter capacitor, resistor R1 and capacitor C2 are the startup circuit, and inductor L1 is the switching power supply step-down energy storage inductor.

[0043] The parameter burning module provides guarantee for burning IP, device ID and other information during device production. It mainly provides TTL communication, which is conventional serial communication. Figure 8 As shown. The parameter burning module includes an insertion terminal J3, which is a 6-PIN-2.54 pitch male terminal, which can be inserted using the corresponding female terminal. Pin 1 of the insertion terminal J3 is connected to a 3.3V power supply through a resistor R19. When burning, that is, TTL communication, power supply is required. Pin 2 of the insertion terminal J3 is grounded, pin 3 of the insertion terminal J3 is connected to the PC12 pin of the MCU through a resistor R21, and pin 4 of the insertion terminal J3 is connected to the PD2 pin of the MCU through a resistor R23. One end of the insertion terminal J3 is connected to the MCU and the other end is connected to the serial port tool. Pin 3 is for the MCU to send data to the serial port tool, and pin 4 is for the serial port tool to send data to the MCU. Pin 5 of the insertion terminal J3 is connected to one end of the resistor R20 and the PC14 pin of the MCU through a resistor R19. When the terminal is produced in the factory, the insertion will give the MCU a low-level signal. At this time, the data sent by the MCU is the factory mode data, and there is no such level to send the factory mode data. Pin 6 of the plug-in terminal J3 is connected to one end of the resistor R22 and the PC15 pin of the MCU through the resistor R25. When the terminal is inserted in the factory, a low-level signal will be given to the MCU, and the wireless transmission will be started at this time, which is convenient for production verification. The other ends of the resistors R20 and R22 are connected to a 3V power supply. The resistors R20 and R22 act as pull-up resistors to make the pins normally high.

[0044] The interface of the 4G communication module is a standard interface, internally defined, and can be easily replaced with other communication methods, similar to NB or Lora. The interface is as follows Fig. 9 As shown. The 4G communication module uses the Quectel module model EC800E-CN, which has stable performance, large data transmission volume, and full network communication. It is widely used in the fields of automation, smart metering, etc. The VCC pin of the plug terminal J1 is connected to a 3.3V power supply. The GND pin of the plug terminal J1 is grounded. The Ven pin of the plug terminal J1 is connected to one end of the resistor R1 and the PA15 pin of the MCU respectively, and the other end of the resistor R2 is connected to a 3.3V power supply. The resistor R2 is a pull-up resistor, so that the level of the Ven pin is high by default. The MCU can control the level of the Ven pin to control the power on and off of the 4G communication module. The Rx pin of the plug terminal J1 is connected to the PC10 pin of the MCU, and the Tx pin of the plug terminal J1 is connected to the PC11 pin of the MCU. The AT command is transmitted, and the MCU sends the command to the 4G communication module through the PC10 pin, and the reply command of the 4G communication module is returned to the MCU through the PC11 pin. The RST pin of the plug-in terminal J1 is connected to the PB3 pin of the MCU, which is the hardware reset pin. The MCU can pull down the reset module of the PB3 pin. The three OUT pins of the plug-in terminal J1 are connected to the PB4 pin, PB6 pin, and PB8 pin of the MCU respectively. The three IN pins of the plug-in terminal J1 are connected to the PB5 pin, PB7 pin, and PB9 pin of the MCU respectively. The OUT pin and IN pin are used as reserved interfaces to prevent the subsequent modules from adding new functions.

[0045] Figure 10-Figure 14 It is the peripheral circuit of the entire 4G communication module and serves 4G communication. Fig.10The figure shows the connection structure of the Quectel module of the 4G communication module. The VBAT_BB pin and VBAT_RF pin of the Quectel module are both connected to the 3.8V power supply. The 3.8V power supply is grounded through capacitor C27. The VBAT_BB pin and VBAT_RF pin are two power supply interfaces, and the function of capacitor C27 is power supply filtering. The RF_ANT pin of the Quectel module is connected to the external antenna. The SIM_DATA pin, SIM_RST pin, SIM_CLK pin and SIM_VDD pin of the Quectel module are all connected to the SIM card slot module. The SIM card slot module is controlled through the SIM_GND pin grounded, SIM_DATA pin, SIM_RST pin, SIM_CLK pin and SIM_VDD pin. The VDD_EXT pin of the Quectel module is connected to the serial port level matching circuit. When the module operates normally, the VDD_EXT pin has a 1.8V voltage. The TXD pin and RXD pin of the Quectel module are connected to the TXD_M and RXD_M pins of the serial port level matching circuit respectively. The PWRKEY pin of the Quectel module is connected to one end of the resistor R32 and the resistor R33 respectively. The other end of the resistor R32 is connected to the Ven pin of the plug-in terminal J1. The other end of the resistor R33 is grounded. The PWRKEY pin is the power-on pin of the module, which controls the power-on of the module. The resistor R33 is a pull-down resistor, and the resistor R32 is a series resistor. The RESET pin of the Quectel module is connected to the reset module. The PSM_EINT pin, TXD_AUX pin and TXD_DBG pin of the Quectel module are connected to an input pin of the plug-in terminal J1 respectively. The ADC0 pin, RXD_AUX pin and RXD_DBG pin of the Quectel module are connected to an output pin of the plug-in terminal J1 respectively. The PSM_EINT pin controls the module to enter the low power consumption mode, and the ADC0 pin is a reserved port. The USB_VBUS pin, USB_DM pin, USB_DP pin and USB_BOOT pin of the Quectel module are connection test points for updating the module firmware.

[0046] like Fig.11 As shown, the reset module includes a resistor R37 and a capacitor C31. One end of the resistor R37 and the capacitor C31 are connected to the RESET pin of the Quectel module. The other end of the capacitor C31 is grounded. The other end of the resistor R37 is connected to the pin of the MCU to reset the 4G communication module. The function of the reset module is to reset the 4G communication module. The resistor R37 is convenient for debugging. If MCU control is required, it is welded. If no control is required, it is not welded. The voltage C31 is a voltage stabilizing filter capacitor.

[0047] like Fig.12As shown, the power module converts the input voltage into the 3.8V voltage used by the 4G communication module. The switching regulator used is MP2155GQ, the input voltage is 2-5.5V, and the output voltage range is 1.5V-5V.

[0048] like Fig.13 As shown, the SIM card slot module is used to insert the SIM card. The SIM card slot module is a flip-up card holder with higher stability. It is usually composed of a cover and a base. When the SIM card is inserted, the cover is closed to complete the fixation. The card slot of the base of the SIM card slot module is equipped with a SIM card for communication. Due to the existence of the cover, even if the device is vibrated or impacted, it will not cause the SIM card to fall off. The VCC pin of the SIM card slot module is connected to the SIM_VDD pin of the 4G communication module, the Rst pin of the SIM card slot module is connected to the SIM_RST pin of the 4G communication module, the Clk pin of the SIM card slot module is connected to the SIM_CLK pin of the 4G communication module through a resistor R36, and the Clk pin of the SIM card slot module is grounded through a capacitor C30. The resistor R36 and the capacitor C30 form a filter circuit. The DATA pin of the SIM card slot module is respectively connected to the SIM_DATA pin of the 4G communication module, the resistor R35 and one end of the capacitor C29, the other end of the resistor R35 is connected to the SIM_VDD pin, and the other end of the capacitor C29 is grounded. Resistor R35 is a pull-up resistor and capacitor C29 is a filter capacitor.

[0049] like Fig.14As shown in (a) and (b), the function of the serial port level matching circuit is to convert the serial port level of the MCU and the serial port level of the 4G communication module to a matching state. The serial port level of the MCU is 3.3V, and the serial port level of the 4G communication module is 1.8V. The serial port level matching circuit can make the communication between the two parties normal and stable. As shown in the left figure of the serial port level matching circuit, when the MCU sends data to the 4G communication module, the data level is transmitted in the form of "0" and "1". When the level is 0, that is, UART_RX is low, the transistor Q2 is turned on, and the resistor R38 is a pull-up resistor, maintaining the terminal level of the 4G communication module at 1.8V voltage, that is, RXD_M is 1.8V; when the level is 1, that is, UART_RX is high, the transistor Q2 is turned off, and the terminal level of the 4G communication module is maintained at a high level, that is, RXD_M is high, and it is also a high level. The high level is a range. Diode Q2 and resistor R42 are selectively welded. When the 4G communication module supports 3.3V, diode Q2 can be omitted. When the 4G communication module supports 1.8V, resistor R42 can be omitted. As shown in the right figure, when the 4G communication module sends data to the MCU, if the level is low, that is, the TXD_M level is low, transistor Q1 is turned on, and the MCU serial port level is high, that is, UART_TX is high. If the level is high, that is, the TXD_M level is high, transistor Q1 is turned off, and the MCU serial port level is high, that is, UART_TX is high. Resistors R40 and R41 are current limiting resistors.

[0050] The DTU wireless data transmission terminal mentioned in this embodiment is powerful and adaptable, can provide upload solutions for various controllers, has strong scalability, and can replace the communication board according to needs.

[0051] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, 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 DTU wireless data transmission terminal, characterized in that: The invention comprises a shell, a circuit board is arranged in the shell, a main control chip, a data acquisition communication module and a 4G communication module are arranged on the circuit board, the main control chip is connected to the data acquisition communication module and the 4G communication module respectively, the data acquisition communication module is connected to a controller (6), the controller (6) is connected to a plurality of gas detectors (7), the 4G communication module is connected to a cloud platform (1) and a mobile terminal (4) respectively through a base station (3), and the cloud platform (1) is connected to a host computer (2) through a network.

2. The DTU wireless data transmission terminal according to claim 1, characterized in that: The controller (6) is a combustible gas industrial controller, and the gas detector (7) is a methane gas detector.

3. The DTU wireless data transmission terminal according to claim 1 or 2, characterized in that: The main control chip is also connected to a reset circuit, an LED indication module, a power management module, and a parameter burning module. The reset circuit is used to reset registers and memories in the main control chip. The power management module converts input voltage into a voltage used by the main control chip. The parameter burning module is used by the host computer (2) to write configurable information to the main control chip. The LED indication module is arranged on the housing.

4. The DTU wireless data transmission terminal according to claim 3, characterized in that: The main control chip is an MCU, which has 128K flash and 20K RAM.

5. The DTU wireless data transmission terminal according to claim 3, characterized in that: The reset circuit includes a resistor R26 and a capacitor C15 connected in series, the other end of the resistor R26 is connected to a 3.3V power supply, the other end of the capacitor C15 is grounded, and the midpoint of the connection between the resistor R26 and the capacitor C15 is connected to the NRST pin of the MCU of the main control chip.

6. The DTU wireless data transmission terminal according to claim 4 or 5, characterized in that: The LED indication module includes a red LED light, a green LED light and a yellow LED light, the red LED light indicates the network status, the green LED light represents the collection status, and the yellow LED light represents the communication status; one end of the red LED light, the green LED light and the yellow LED light are respectively connected to the control pin of the MCU, and the other ends of the red LED light, the green LED light and the yellow LED light are all connected to a 3.3V power supply through a resistor.

7. The DTU wireless data transmission terminal according to claim 6, characterized in that: The acquisition mode of the acquisition communication module is RS485 mode or TTL mode, one end of the RS485 mode or TTL mode circuit is connected to the control pin of the MCU, and the other end of the RS485 mode or TTL mode circuit is connected to the output end of the controller (6); the power management module is a level conversion circuit, and the level conversion circuit converts the input 24V voltage into a voltage value used by the MCU and the 4G communication module.

8. The DTU wireless data transmission terminal according to claim 4 or 7, characterized in that: The parameter burning module includes an insertion terminal J3, which is a 6-PIN-2.54 pitch male terminal; one end of the insertion terminal J3 is connected to the MCU and the other end is connected to the serial port tool; the 4G communication module is a Quectel module, which is connected to a 3.3V power supply and the MCU of the main control chip through the plug-in terminal J1.

9. The DTU wireless data transmission terminal according to claim 8, characterized in that: The 4G communication module is respectively connected to the SIM card slot module, the serial port level matching circuit, the plug-in terminal J1, the reset module and the power module, and the serial port level matching circuit is connected to the MCU.

10. The DTU wireless data transmission terminal according to claim 9, characterized in that: The reset module includes a resistor R37 and a capacitor C31, one end of the resistor R37 and the capacitor C31 are connected to the RESET pin of the Quectel module, the other end of the capacitor C31 is grounded, and the other end of the resistor R37 is connected to the MCU; the power module includes a switching regulator, which converts the input voltage into a 3.8V voltage used by the 4G communication module; the SIM card slot module is a flip-top card holder, which includes a cover and a base, the cover and the base are detachably connected, and the base is plugged into the SIM card; The function of the serial port level matching circuit is to convert the serial port level of the MCU and the serial port level of the 4G communication module to a matching state.

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