A multifunction embedded control circuit

Abstract

The utility model embodiment provides a kind of multifunctional embedded control circuit, comprising: microcontroller, signal acquisition module, multistage power management module, signal isolation module, protection module and communication interface module;Signal acquisition module includes multichannel analog-digital converter and general input-output port, multichannel analog-digital converter is connected with microcontroller, for collecting the analog signal of external sensor and conversion is multichannel analog sampling data;General input-output port is connected with microcontroller, for obtaining the digital signal of external equipment and obtains digital input data;Signal acquisition module further includes clock system and memory, clock system is for analog-digital converter and general input-output port to provide synchronous clock signal, memory is used to store analog sampling data and digital input data.Effectively inhibit electromagnetic interference, improve signal integrity and system stability.

Description

Technical Field

[0001] This utility model relates to the field of information technology, and in particular to a multifunctional embedded control circuit. Background Technology

[0002] Embedded control systems face complex electromagnetic environments in practical applications, with common-mode noise interference across multiple voltage domains severely impacting system stability and reliability. Particularly in multifunctional embedded control circuits employing high-performance microcontrollers such as the STM32F429, the cross-coupling of digital and analog circuits leads to signal distortion, reducing ADC sampling accuracy and communication quality. Simultaneously, external power supply fluctuations and surge impacts also pose potential threats to the system. These interconnected issues constitute a challenging technical problem: how to effectively suppress various electromagnetic interferences and improve signal integrity while ensuring the system's functional diversity? Specifically, it is necessary to address the impact of digital noise on analog circuits, the interference of power supply ripple on the core voltage, and the damage to components caused by external surges. This not only affects the performance of individual modules but also the stable operation of the entire system. Especially in applications requiring high-precision real-time control, ensuring the reliable execution of control algorithms under complex electromagnetic environments becomes a crucial issue that urgently needs to be addressed. Utility Model Content

[0003] In view of the above problems, this utility model is proposed to provide a multifunctional embedded control circuit that overcomes or at least partially solves the above problems, effectively suppressing electromagnetic interference and improving signal integrity and system stability. Through optimized hardware module design, it solves problems such as multi-voltage domain common-mode noise interference, power supply ripple, and external surge impact, thereby improving system stability and reliability.

[0004] This utility model provides a multifunctional embedded control circuit, which mainly includes: a microcontroller, a signal acquisition module, a multi-level power management module, a signal isolation module, a protection module, and a communication interface module;

[0005] The signal acquisition module includes a multi-channel analog-to-digital converter and a general-purpose input / output port. The multi-channel analog-to-digital converter is connected to a microcontroller and is used to acquire analog signals from external sensors and convert them into multi-channel analog sampling data.

[0006] The general purpose input / output port connects to the microcontroller to acquire digital signals from external devices and obtain digital input data;

[0007] The signal acquisition module also includes a clock system and a memory. The clock system provides a synchronous clock signal for the analog-to-digital converter and the general-purpose input / output port, while the memory is used to store analog sampling data and digital input data.

[0008] Preferably, the multi-level power management module is connected to the microcontroller and peripherals, and includes a linear regulator, a filter network, an independent power domain, and a reference voltage source;

[0009] The linear regulator converts the input voltage to the core voltage;

[0010] The filter network decouples the core voltage to obtain a stable supply voltage;

[0011] Independent power domains provide separate power to the analog and digital circuits of the microcontroller;

[0012] The reference voltage source provides a reference voltage for the analog-to-digital converter;

[0013] The multi-level power management module also includes a backup power supply circuit, a low-power mode switching circuit, a multi-channel voltage monitoring circuit, and a feedback control circuit. The backup power supply circuit provides an independent power supply for the microcontroller's real-time clock, the low-power mode switching circuit reduces the microcontroller's standby power consumption, the multi-channel voltage monitoring circuit detects the output voltage of the multi-level power management module, and the feedback control circuit adjusts the output voltage stability.

[0014] Preferably, the signal isolation module includes a ferrite bead isolation element, a level conversion circuit, and an isolation drive circuit;

[0015] Ferrite bead isolation elements isolate the input / output ports of a microcontroller from external interfaces;

[0016] The level conversion circuit performs level matching on the input signal to obtain a matched signal;

[0017] The isolation drive circuit performs level isolation on the output signal to obtain an isolated control signal, which is used to drive external devices.

[0018] Preferably, the protection module includes a transient suppression diode, a resettable fuse, and a bypass capacitor;

[0019] Transient suppression diodes provide surge protection for the input power supply, resulting in a protected power signal.

[0020] The self-resetting fuse limits overcurrent and obtains the power signal after current limiting;

[0021] Bypass capacitors filter out high-frequency noise to obtain a low-noise power signal.

[0022] Preferably, the communication interface module includes a controller local area network bus interface, a serial communication interface, a universal serial bus interface, and an expansion interface, which are used to transmit the control signals processed by the microcontroller to industrial equipment, data acquisition equipment, host computer, and external display device, respectively.

[0023] The present invention has the following advantages:

[0024] This invention employs a multi-module collaborative design, utilizes an independent power domain design to suppress cross-coupling between digital and analog signals, generates a stable power supply using a linear regulator and filter network, and incorporates transient suppression diodes and self-resetting fuses to achieve surge protection and overcurrent protection. Furthermore, it enhances signal isolation through ferrite bead isolation components and level conversion circuits. This effectively solves problems related to power supply noise, signal interference, and communication reliability in embedded systems, significantly improving the anti-interference capability and signal integrity of the control circuit, and providing a reliable hardware foundation for the stable execution of real-time control algorithms. Attached Figure Description

[0025] To more clearly illustrate the technical solution of this utility model, the drawings used in the description of this utility model will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 This is a schematic diagram of the module structure of a multifunctional embedded control circuit provided in one embodiment of the present invention;

[0027] Figure 2 This is a circuit diagram of the first part of a microcontroller module for a multifunctional embedded control circuit provided in one embodiment of the present invention;

[0028] Figure 3 This is a second part of the circuit diagram of a microcontroller module for a multifunctional embedded control circuit provided in one embodiment of the present invention;

[0029] Figure 4 This is a circuit diagram of the first part of a signal acquisition module of a multifunctional embedded control circuit provided in an embodiment of the present invention;

[0030] Figure 5 This is a second part of the circuit diagram of the signal acquisition module of a multifunctional embedded control circuit provided in one embodiment of the present invention;

[0031] Figure 6 yes Figure 4 Enlarged view of section A in the middle;

[0032] Figure 7 yes Figure 5 Enlarged view of section B;

[0033] Figure 8 This is a circuit diagram of the third part of a signal acquisition module of a multifunctional embedded control circuit provided in an embodiment of this utility model;

[0034] Figure 9This is a circuit diagram of the fourth part of a signal acquisition module of a multifunctional embedded control circuit provided in one embodiment of this utility model;

[0035] Figure 10 This is an RS232 circuit diagram of a multifunctional embedded control circuit provided in one embodiment of the present invention;

[0036] Figure 11 This is a circuit diagram of a protection module of a multifunctional embedded control circuit provided in one embodiment of the present invention;

[0037] Figure 12 This is a circuit diagram of the first part of the communication interface module of a multifunctional embedded control circuit provided in an embodiment of the present invention;

[0038] Figure 13 This is a second part of the circuit diagram of the communication interface module of a multifunctional embedded control circuit provided in one embodiment of the present invention;

[0039] Figure 14 This is a circuit diagram of the third part of a communication interface module of a multifunctional embedded control circuit provided in an embodiment of this utility model;

[0040] Figure 15 This is a circuit diagram of the fourth part of the communication interface module of a multifunctional embedded control circuit provided in one embodiment of the present invention;

[0041] Figure 16 This is the fifth part of the circuit diagram of the communication interface module of a multifunctional embedded control circuit provided in one embodiment of the present invention;

[0042] Figure 17 This is the sixth part of the circuit diagram of the communication interface module of a multifunctional embedded control circuit provided in one embodiment of the present invention;

[0043] Figure 18 This is a circuit diagram of the first part of a three-level power management module of a multifunctional embedded control circuit provided in an embodiment of this utility model;

[0044] Figure 19 This is a circuit diagram of the second part of a three-level power management module for a multi-functional embedded control circuit provided in one embodiment of the present invention;

[0045] Figure 20 This is a circuit diagram of the third part of a three-level power management module for a multifunctional embedded control circuit provided in one embodiment of this utility model;

[0046] Figure 21 This is the fourth part of the circuit diagram of a three-level power management module for a multifunctional embedded control circuit provided in one embodiment of this utility model. Detailed Implementation

[0047] To make the above-mentioned objectives, features, and advantages of this utility model more apparent and understandable, the present utility model will be further described in detail below with reference to the accompanying drawings and specific embodiments. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0048] Reference Figure 1 As shown in the figure, an embodiment of this utility model provides a multifunctional embedded control circuit, including: a microcontroller 10, a signal acquisition module 20, a multi-level power management module 30, a signal isolation module 40, a protection module 50, and a communication interface module 60. The signal acquisition module 20 includes a multi-channel analog-to-digital converter (ADC) and a general-purpose input / output (GPIO) port. The ADC is connected to the microcontroller 10 and is used to acquire analog signals from external sensors and convert them into multiple channels of analog sampling data. The GPIO port is also connected to the microcontroller 10 and is used to acquire digital signals from external devices and obtain digital input data. The signal acquisition module 20 further includes a clock system and a memory. The clock system provides a synchronous clock signal for the ADC and the GPIO port, and the memory stores the analog sampling data and digital input data.

[0049] The microcontroller 10 described above can preferably use an STM32F429 as the core control unit, such as Figure 2 and Figure 3 As shown, the main control chip, STM32F429IGT6 (ARM Cortex-M4 core), is responsible for overall system control, data processing, and peripheral management. Its rich peripheral interfaces (such as GPIO, ADC, DAC, CAN, SPI, I2C, etc.) support multi-functional integration.

[0050] For example, the circuit corresponding to the STM32F429IGT6 core processor described above can be configured with a 3.3V analog power supply for the multi-channel ADC module and a 1.8V digital power supply for the communication module. The VDDA can also use an LC filter network and be independently grounded with the VSSA. The digital power domain uses an LDO regulator (such as the LM1117) and the analog power domain uses a low-noise LDO (such as the TL431), forming two independent power supply networks to isolate digital switching noise. Using SPICE simulation tools to load a noise model in the 10MHz~100MHz frequency band, the crosstalk amplitude from the digital domain to the analog domain was measured to exceed the -50dB threshold. When laying out the above circuit on the PCB, a 20mil isolation band is set on the power separation layer to ensure that the distance between the analog and digital ground planes is greater than 3mm. The PCB can be designed as a four-layer stack (signal-ground-power-signal), with the copper foil areas of the analog and digital domains separated on the power layer, maintaining a spacing of more than 5mm.

[0051] In some embodiments of this application, the multi-level power management module 30 is connected to the microcontroller 10 and peripherals, and includes a linear regulator, a filter network, an independent power domain, and a reference voltage source. The linear regulator converts the input voltage into a core voltage. The filter network decouples the core voltage to obtain a stable supply voltage. The independent power domain supplies power to the analog and digital circuits of the microcontroller 10 respectively. The reference voltage source provides a reference voltage for the analog-to-digital converter. The multi-level power management module 30 also includes a backup power supply circuit, a low-power mode switching circuit, a multi-channel voltage monitoring circuit, and a feedback control circuit. The backup power supply circuit provides an independent power supply to the real-time clock of the microcontroller 10. The low-power mode switching circuit reduces the standby power consumption of the microcontroller 10. The multi-channel voltage monitoring circuit detects the output voltage of the multi-level power management module 30, and the feedback control circuit adjusts the stability of the output voltage.

[0052] A 3.3V core voltage is generated using an LM1117IMPX-3.3 linear regulator. Combined with a π-type filter network, conducted interference signals below 200MHz can be filtered out, stabilizing the power supply signal. The TM32F429IGT6 core processor is powered by the LM1117IMPX-3.3 linear regulator generating a 3.3V core voltage. The aforementioned π-type filter network stabilizes the power supply signal. When the ripple voltage exceeds 50mV, the capacitance values ​​in the π-type filter network are adjusted to optimize the filter parameters.

[0053] Signal acquisition module 20, such as Figures 4 to 9 As shown, a 10MS / s sampling rate can be used to capture the power supply waveform during AD sampling. If 5ns-level digital noise coupling is found, a TVS diode can be added to the signal path, such as... Figure 4 and Figure 6As shown, the noise amplitude of TVS diodes Q54 and D113 decreased from 300mV to 50mV. The SM712.TCT series TVS diodes, located at the power input, provide 30A / 8ms surge protection for transient overvoltage suppression in power lines. These SM712.TCT series TVS diodes, located at the STM32F429 power input, have a maximum peak pulse current of 30A and a pulse width of 8ms. The STM32F429 power input has a forward voltage of 5V and a reverse breakdown voltage of 12V, and is connected in parallel between the positive and negative terminals of the power supply.

[0054] like Figure 2 and Figure 3 As shown, a ferrite bead isolation layout is used for ports PG0-PG15 and PH0-PH15 to obtain an isolated signal channel that blocks digital noise backflow. Hardware layout data for ports PG0-PG15 and PH0-PH15 using an STM32F429IGT6 is presented. During the design process, based on the port signal transmission path, the ferrite bead isolation layout design data (FB1-FB8) is loaded to generate a distribution model of the isolation components between ports, obtaining the isolation component parameters. Using the isolation component parameters, the inductance impedance characteristics between ports PGx and PHx are calculated to obtain the common-mode noise suppression capability in the 20MHz to 1GHz frequency band, determining the noise blocking effect. Based on the power supply noise coupling suppression parameters, π-type filter network data (C78 / C79 / C80), etc., are loaded to calculate the filtering characteristics of conducted interference below 200MHz, determining the low-frequency noise suppression capability. Using the low-frequency noise suppression capability, combined with the TL431AIDBZR reference source circuit data, such as Q1 and Q2 mentioned above, a stable output model of the ADC reference voltage is generated to obtain the reference voltage fluctuation range and determine the signal acquisition accuracy. If the signal acquisition accuracy reaches ±1.5LSB, the three-level noise suppression strategy data (TVS tube SM712.TCT, GPIO isolation) is extracted to generate the system signal-to-noise ratio improvement model, and a signal-to-noise ratio parameter of 72dB is obtained.

[0055] The signal isolation module 40 includes a ferrite bead isolation element, a level conversion circuit, and an isolation drive circuit. The ferrite bead isolation element isolates the input / output ports of the microcontroller 10 from the external interface. The level conversion circuit performs level matching on the input signal to obtain a matched signal. The isolation drive circuit performs level isolation on the output signal to obtain an isolated control signal for driving external devices.

[0056] In some embodiments of this application, the system includes a microcontroller 10, a signal acquisition module 20, a multi-level power management module 30, a signal isolation module 40, a protection module 50, and a communication interface module 60. The signal acquisition module 20 includes a multi-channel analog-to-digital converter (ADC) and a general-purpose input / output (GPIO) port. The ADC is connected to the microcontroller 10 and is used to acquire analog signals from external sensors and convert them into multiple channels of analog sampling data. The GPIO port is also connected to the microcontroller 10 and is used to acquire digital signals from external devices and obtain digital input data. The signal acquisition module 20 further includes a clock system and a memory. The clock system provides a synchronous clock signal for the ADC and the GPIO port, and the memory stores the analog sampling data and digital input data. The aforementioned multifunctional embedded control system based on the microcontroller 10 uses the STM32F429IGT6 microcontroller 10 as its core.

[0057] Furthermore, refer to Figures 18 to 21 As shown, the multi-level power management module 30 is connected to the microcontroller 10 and peripherals, and includes a linear regulator, a filter network, an independent power domain, and a reference voltage source. The linear regulator converts the input voltage into a core voltage. The filter network decouples the core voltage to obtain a stable supply voltage. The independent power domain supplies power to the analog and digital circuits of the microcontroller 10 respectively. The reference voltage source provides a reference voltage for the analog-to-digital converter. The multi-level power management module 30 also includes a backup power supply circuit, a low-power mode switching circuit, a multi-channel voltage monitoring circuit, and a feedback control circuit. The backup power supply circuit provides an independent power supply for the real-time clock of the microcontroller 10. The low-power mode switching circuit reduces the standby power consumption of the microcontroller 10. The multi-channel voltage monitoring circuit detects the output voltage of the multi-level power management module 30, and the feedback control circuit adjusts the stability of the output voltage.

[0058] The linear regulator used is the LM1117IMPX-3.3, which converts the input 5V voltage to a 3.3V core voltage. A π-type filter network, consisting of a 10μF ceramic capacitor, a 1μH inductor, and a 22μF capacitor, decouples the core voltage and filters out conducted interference below 200MHz. In the independent power domain design, the digital power domain uses an LDO regulator TPS7A4701, and the analog power domain uses a low-noise LDOLP5907, powering the digital and analog circuits of the microcontroller 10, respectively. The reference voltage source is a TL431AIDBZR, providing a stable 2.5V reference voltage for the MCP3208. A backup power supply circuit provides an independent power supply for the microcontroller 10's real-time clock, ensuring normal operation after the main power supply fails; a low-power mode switching circuit allows the microcontroller 10 to enter a low-power state during standby, reducing power consumption.

[0059] In some embodiments of this application, the signal isolation module 40 includes a ferrite bead isolation element, a level conversion circuit, and an isolation drive circuit. The ferrite bead isolation element isolates the input / output ports of the microcontroller 10 from the external interface. The level conversion circuit performs level matching on the input signal to obtain a matched signal. The isolation drive circuit performs level isolation on the output signal to obtain an isolated control signal for driving external devices. Ferrite bead isolation elements FB1-FB8 (100Ω@100MHz model) are set between the PG0-PG15 and PH0-PH15 ports of the STM32F429IGT6 to isolate the input / output ports of the microcontroller 10 from the external interface. The level conversion circuit performs level matching on the input signal to make the external signal compatible with the input level of the microcontroller 10. The isolation drive circuit performs level isolation on the output signal to ensure that the output control signal is stable and reliable and can effectively drive external devices. The signal acquisition module 20, specifically, uses an MCP3208 multi-channel analog-to-digital converter, with its CH0-CH7 channels connected to external sensors for acquiring 8 channels of analog signals. The STM32F429IGT6's general purpose input / output (GPIO) ports connect to external devices to acquire digital signals. The clock system uses a 25MHz external crystal oscillator, with a PLL frequency multiplier circuit within the microcontroller 10 providing a synchronous clock signal for the analog-to-digital converter and GPIO ports. The memory utilizes the microcontroller 10's internal SRAM to store the acquired analog sampling data and digital input data.

[0060] In some embodiments of this application, such as Figure 11 As shown, the protection module 50 includes a transient suppression diode, a resettable fuse, and a bypass capacitor. The transient suppression diode provides surge protection for the input power supply, resulting in a protected power signal. The resettable fuse limits overcurrent, providing a current-limited power signal. The bypass capacitor filters out high-frequency noise, providing a low-noise power signal. An SM712.TCT series TVS diode is connected in parallel at the power input terminal to achieve 30A / 8ms surge protection. The resettable fuse is connected in series in the power circuit to limit overcurrent. A 0.1μF ceramic capacitor is used as the bypass capacitor and is connected in parallel between the power supply and ground to filter out high-frequency noise. The analog ground and digital ground are isolated by a ferrite bead, with a 20mil isolation band to ensure that the distance between the analog and digital ground planes is greater than 3mm, reducing common-mode noise interference.

[0061] In some embodiments of this application, such as Figures 12 to 17As shown, the communication interface module 60 includes a controller area network bus interface, a serial communication interface, a universal serial bus interface, and an expansion interface, which are used to transmit the control signals processed by the microcontroller 10 to industrial equipment, data acquisition equipment, a host computer, and an external display device, respectively. Specifically, the CAN bus interface is configured with a TJA1050T transceiver, with a 100nF ceramic capacitor connected in parallel at the power input terminal, and 120Ω terminating resistors connected in series and 47pF capacitors connected in parallel on the CAN_H and CAN_L signal lines, respectively, to achieve stable data transmission of the industrial-grade communication interface. Figure 10 As shown, the RS-232 serial communication module uses the SP3232EUEY chip. The voltage range of the T1IN and R1OUT pins is set to ±5V to ±15V to achieve level conversion and ensure compatibility with communication protocols of external devices. The general-purpose serial bus interface and expansion interface are used to connect to the host computer and external display devices, respectively, to achieve data transmission and display.

[0062] This invention effectively solves various interference problems existing in embedded systems through the coordinated work of various modules, improves the stability and reliability of the system, and is suitable for fields with high requirements for embedded control systems, such as industrial control and medical equipment.

[0063] Although preferred embodiments of the present invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of the present invention.

[0064] Finally, it should be noted that in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or terminal device that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or terminal device. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or terminal device that includes said element.

[0065] The above provides a detailed description of a multifunctional embedded control circuit provided by this utility model. Specific examples have been used to illustrate the principle and implementation of this utility model. The description of the above embodiments is only for the purpose of helping to understand the method and core idea of ​​this utility model. At the same time, for those skilled in the art, there will be changes in the specific implementation and application scope based on the idea of ​​this utility model. Therefore, the content of this specification should not be construed as a limitation of this utility model.

Claims

1. A multifunctional embedded control circuit, characterized in that, It includes a microcontroller (10), a signal acquisition module (20), a multi-level power management module (30), a signal isolation module (40), a protection module (50), and a communication interface module (60). The signal acquisition module (20) includes a multi-channel analog-to-digital converter and a general-purpose input / output port. The multi-channel analog-to-digital converter is connected to the microcontroller (10) and is used to acquire analog signals from external sensors and convert them into multi-channel analog sampling data. The general purpose input / output port is connected to the microcontroller (10) to acquire digital signals from external devices and obtain digital input data; The signal acquisition module (20) also includes a clock system and a memory. The clock system provides a synchronous clock signal for the analog-to-digital converter and the general-purpose input / output port, and the memory is used to store analog sampling data and digital input data.

2. The multifunctional embedded control circuit according to claim 1, characterized in that, The multi-level power management module (30) is connected to the microcontroller (10) and peripherals, including a linear regulator, a filter network, an independent power domain and a reference voltage source; The linear regulator converts the input voltage to the core voltage; The filter network decouples the core voltage to obtain a stable supply voltage; Independent power domains provide power to the analog and digital circuits of the microcontroller (10) respectively; The reference voltage source provides a reference voltage for the analog-to-digital converter; The multi-level power management module (30) also includes a backup power supply circuit, a low-power mode switching circuit, a multi-channel voltage monitoring circuit, and a feedback control circuit. The backup power supply circuit provides an independent power supply for the real-time clock of the microcontroller (10), the low-power mode switching circuit reduces the standby power consumption of the microcontroller (10), the multi-channel voltage monitoring circuit detects the output voltage of the multi-level power management module (30), and the feedback control circuit adjusts the stability of the output voltage.

3. The multifunctional embedded control circuit according to claim 1, characterized in that, The signal isolation module (40) includes a magnetic bead isolation element, a level conversion circuit, and an isolation drive circuit; The magnetic bead isolation element isolates the input / output ports of the microcontroller (10) from the external interface; The level conversion circuit performs level matching on the input signal to obtain a matched signal; The isolation drive circuit performs level isolation on the output signal to obtain an isolated control signal, which is used to drive external devices.

4. The multifunctional embedded control circuit according to claim 1, characterized in that, The protection module (50) includes a transient suppression diode, a self-resetting fuse, and a bypass capacitor; Transient suppression diodes provide surge protection for the input power supply, resulting in a protected power signal. The self-resetting fuse limits overcurrent and obtains the power signal after current limiting; Bypass capacitors filter out high-frequency noise to obtain a low-noise power signal.

5. The multifunctional embedded control circuit according to claim 1, characterized in that, The communication interface module (60) includes a controller local area network bus interface, a serial communication interface, a universal serial bus interface and an expansion interface, which are used to transmit the control signals processed by the microcontroller (10) to industrial equipment, data acquisition equipment, host computer and external display device, respectively.

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