Modbus data acquisition module for a heat pump device

Abstract

This invention discloses a MODBUS data acquisition module for heat pump devices, belonging to the field of data acquisition technology. The module includes a power supply module, an analog input unit, an analog-to-digital converter module, a microprocessor, a MODBUS-RTU communication interface, and input / output interfaces. The power supply module provides isolated and low-noise power to each component; the analog input unit is used to receive signals from various sensors; the analog-to-digital converter module converts analog signals into digital signals; the microprocessor is responsible for signal processing and MODBUS protocol encapsulation; the communication interface enables bidirectional communication with a host computer; and the input / output interfaces provide both digital and analog control functions. This invention's module is highly integrated, solving the problems of slow acquisition speed, limited signal types, poor scalability, and complex wiring inherent in traditional PLC modules. It is particularly suitable for distributed data acquisition and monitoring systems for heat pump devices.

Description

Technical Field

[0001] This invention relates to the field of industrial automation and data acquisition technology, and in particular to a MODBUS data acquisition module for heat pump devices. Background Technology

[0002] Existing heat pump systems primarily use PLC analog modules for data acquisition, which involves hardware connection, signal conditioning, AD conversion, and data processing. However, PLC modules are limited by their scan cycle and have low sampling rates, making them unsuitable for high-speed applications. Furthermore, their signal types are limited, the number of channels is small, and expansion costs are high, making it difficult to meet the diverse signal acquisition needs of heat pump systems.

[0003] Therefore, it is necessary to provide a new technical solution. Summary of the Invention

[0004] The purpose of this invention is to provide a MODBUS data acquisition module for heat pump devices, so as to solve the problems of slow acquisition speed, single signal type, poor scalability and high cost in the prior art.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A MODBUS data acquisition module for a heat pump device, comprising:

[0007] Power module for providing wide voltage input and isolated power supply;

[0008] Analog input unit, used to receive analog signals from sensors;

[0009] An analog-to-digital conversion module, including at least one high-speed ADC chip, is used to convert analog signals into digital signals;

[0010] The microprocessor is used to control the ADC sampling timing, perform data preprocessing, and encapsulate the protocol.

[0011] The MODBUS-RTU communication interface is used for bidirectional data communication with the host computer; and

[0012] The input / output interface includes digital input units, digital output units, and analog output units.

[0013] The analog input unit is connected to the analog-to-digital converter module; the analog-to-digital converter module is bidirectionally connected to the microprocessor; the microprocessor is connected to the communication interface and the input / output interface respectively; the power supply module provides power to the active circuit in the analog input unit, the analog-to-digital converter module, the microprocessor, the communication interface, and the input / output interface.

[0014] Furthermore, the power supply module, analog input unit, analog-to-digital converter module, microprocessor, communication interface, and input / output interface are all integrated on a single PCB board.

[0015] Furthermore, the PCB board has integrated terminal blocks on its opposite edges for the input and output of all external signals.

[0016] Furthermore, the integrated terminal block includes:

[0017] Power input terminal for connecting to a 9-36VDC power supply;

[0018] Analog input terminal block, used to connect 4-20mA current signal and 0-10V voltage signal;

[0019] Temperature sensor input terminal group, used to connect PT100 / PT1000 / NTC temperature sensor signals;

[0020] Digital input terminal block;

[0021] Switch output terminal group;

[0022] Analog output terminal blocks; and

[0023] RS-485 communication terminal, used to connect A / B signal lines.

[0024] Furthermore, the physical port layout of the terminal block is shown in the table below:

[0025] 1 24 / 0 powered by 2 GND / 5V Output 5V voltage 3 (Y1 / Y1)~(Y8 / Y8) Switch output signal 4 1M / (X1~X6) Digital input signal 5 1M / (X7~X12) Digital input signal 6 COM / (I1~I4) 4-20mA analog input signal 7 COM / (V1~V4) 0-10V analog input signal 8 COM / (R1~R8) PT100 / PT1000 input signal 9 MO / (AV1~AV3) Analog output signal 10 A / B RS-485 external communication interface

[0026] Furthermore, the power module includes an isolated DC-DC converter circuit and a low-noise LDO for providing a stable, low-noise power supply to the ADC.

[0027] Furthermore, the analog-to-digital conversion module supports resolutions from 12 bits to 24 bits.

[0028] Furthermore, the microprocessor supports MODBUS RTU and MODBUS TCP protocol conversion, and the communication baud rate, verification method, and slave address can be set via DIP switches or software.

[0029] Furthermore, the module is connected to a host computer or external device via an RS-485 bus to form a distributed data acquisition and control system.

[0030] The present invention has the following beneficial effects:

[0031] 1. High acquisition rate and wide application range: Adopting an independent high-speed ADC and microprocessor architecture, it breaks through the limitations of traditional PLC scanning cycles, and the sampling rate can be flexibly configured from 10Hz to over 1MHz. It can not only meet the acquisition of slowly changing signals such as temperature and pressure, but also handle high-speed dynamic signal processing such as vibration analysis and transient current capture, greatly expanding its application in in-depth diagnosis and performance analysis of heat pump systems.

[0032] 2. Excellent measurement accuracy and stability: Through a dual power supply purification design—combining isolated DC-DC conversion and a low-noise LDO dedicated to ADC power supply—ground loop interference and power supply noise are eliminated at their source. This ensures high accuracy of 0.5% for current and voltage signals, as well as the realization of ultra-high resolution for a 24-bit Σ-Δ ADC, guaranteeing data accuracy and long-term stability.

[0033] 3. High integration, significantly reduced hardware costs: Multiple analog inputs (4-20mA, 0-10V, PT100 / PT1000 / NTC), digital inputs / outputs, and analog outputs are highly integrated into a single module. Users do not need to purchase expensive dedicated PLC modules for each signal type, directly reducing hardware procurement costs, spare parts inventory costs, and logistics management costs.

[0034] 4. Distributed architecture significantly reduces cabling and installation costs: Modules can be distributed and installed near the sensors, connecting to the host computer via a single RS-485 bus, replacing the numerous, long-distance analog signal cables of traditional solutions. This can save over 70% on material costs for cables, cable trays, conduits, etc., and significantly reduce installation time and labor costs.

[0035] 5. Strong signal type compatibility: A single module supports multiple signals such as current, voltage, resistance, and switching signals, providing extremely strong flexibility of "one module for multiple uses" and easily adapting to the diversity of sensor types in heat pump systems and the needs of subsequent modification and upgrades.

[0036] 6. Convenient hardware and software configuration: Communication parameters (baud rate, parity check) and slave address can be quickly set on the hardware via DIP switches or flexibly configured via software, making debugging and changes extremely convenient.

[0037] 7. Easy system expansion: Based on the standard MODBUS-RTU protocol and RS-485 bus network, system expansion only requires connecting a new module to the bus and setting a unique address. Theoretically, it can easily support up to 247 slave stations, with strong scalability and no need to change the master station structure.

[0038] 8. Simple layout, easy to maintain: The distributed cabling and high integration features make the wiring inside the control cabinet clear and neat, greatly reducing the difficulty of later inspection and maintenance.

[0039] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0040] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0041] Figure 1 This is a structural principle block diagram of the MODBUS data acquisition module of the present invention.

[0042] Figure 2 This is a schematic diagram of the terminal distribution and functions of the MODBUS data acquisition module of the present invention. Detailed Implementation

[0043] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0044] This invention discloses a MODBUS data acquisition module for a heat pump device, with reference to... Figure 1 and Figure 2 It includes: a power supply module 1, an analog input unit 2, an analog-to-digital conversion module 3, a microprocessor 4, a MODBUS-RTU communication interface 5, and an input / output interface 6.

[0045] Power module 1 provides wide voltage input and isolated power supply. Analog input unit 2 is used to receive analog signals from sensors. Analog-to-digital converter module 3 includes at least one high-speed ADC chip for converting analog signals into digital signals. Microprocessor 4 controls the ADC sampling timing, performs data preprocessing, and protocol encapsulation. MODBUS-RTU communication interface 5 is used for bidirectional data communication with a host computer. Input / output interface 6 includes a digital input unit 61, a digital output unit 62, and an analog output unit 63.

[0046] The analog input unit 2 is connected to the analog-to-digital converter module 3; the analog-to-digital converter module 3 is bidirectionally connected to the microprocessor 4; the microprocessor 4 is connected to the communication interface 5 and the input / output interface 6 respectively; the power supply module 1 provides power to the active circuit in the analog input unit 2, the analog-to-digital converter module 3, the microprocessor 4, the communication interface 5 and the input / output interface 6.

[0047] The power supply module 1, analog input unit 2, analog-to-digital converter module 3, microprocessor 4, communication interface 5, and input / output interface 6 are all integrated on a single PCB board 7. Integrated terminal blocks 71 are provided on opposite edges of the PCB board 7 for the input and output of all external signals.

[0048] The integrated terminal block 71 includes:

[0049] The power input terminal is used to connect a 9-36VDC power supply, which corresponds to power module 1.

[0050] The analog input terminal group is used to connect 4-20mA current signals and 0-10V voltage signals, which corresponds to analog signal input module 2;

[0051] Temperature sensor input terminal group is used to connect PT100 / PT1000 / NTC temperature sensor signals. It corresponds to the PT100 / PT1000 signal input area and corresponds to analog signal input module 2.

[0052] A digital input terminal group, which corresponds to a digital signal input module 61;

[0053] A digital output terminal group, which corresponds to a digital signal output module 62;

[0054] Analog output terminal group, corresponding to analog signal output module 63; and

[0055] The RS-485 communication terminal is used to connect the A / B signal lines, and it corresponds to RS-485 communication interface 5.

[0056] The specific physical port layout of the terminal block 71 is shown in the table below:

[0057]

[0058]

[0059] The power supply module 1 includes an isolated DC-DC converter circuit and a low-noise LDO, used to provide a stable, low-noise power supply for the ADC. The analog-to-digital converter module 3 supports 12-bit to 24-bit resolution.

[0060] The microprocessor 4 supports MODBUS RTU and MODBUS TCP protocol conversion, and the communication baud rate, verification method and slave address can be set via DIP switch or software.

[0061] The module is connected to the host computer or external device 8 via RS-485 bus 5 to form a distributed data acquisition and control system.

[0062] The workflow and control logic are as follows:

[0063] 1. System Initialization: After the module is connected to a 9-36VDC power supply, the power module starts working, supplying power to various components through an isolated DC-DC converter and a low-noise LDO to avoid ground loop interference and ensure stable operation of the ADC. The microprocessor starts up, initializes internal registers, interrupt system, timers, etc., configures ADC sampling parameters, and sets the sampling rate and resolution. Simultaneously, the MODBUS-RTU communication interface is initialized, setting the communication baud rate, parity method, and slave address. These parameters can be adjusted via software or DIP switches to enhance flexibility. Furthermore, the input / output interfaces are initialized to prepare them for receiving and transmitting signals.

[0064] 2. Data Acquisition: The module employs corresponding acquisition methods for different signal types. Current and voltage signals are directly connected to the corresponding channels; for current inputs, V and I must be shorted. Temperature signals (PT100, PT1000, or NTC) are converted into suitable electrical signals by a conditioning circuit before being input. These analog signals are converted by a 12-24 bit ADC. The microprocessor selects the sampling rate based on the signal characteristics: low speed for temperature and pressure signals, and high speed for vibration and transient current analysis. Digital signals are directly acquired through the digital input unit to obtain equipment status information.

[0065] 3. Data Processing and Conversion: The microprocessor receives the digital signal converted by the ADC, first performing filtering to remove noise and interference, improving data accuracy. Next, it performs unit conversion, transforming the raw data into actual physical quantities, such as converting a digital voltage value into a volt value. The processed data is then encapsulated according to requirements, either into the MODBUS RTU protocol for local communication or converted to the MODBUS-TCP protocol for remote data acquisition and monitoring, adapting to different application scenarios.

[0066] 4. Data Transmission and Interaction: Processed and encapsulated data is transmitted to a host computer, such as a PLC or computer, via an RS-485 interface using the MODBUS-RTU protocol. The host computer can acquire data in real time and monitor the operating status of the heat pump unit. Simultaneously, the module receives commands from the host computer through this interface, such as adjusting sampling parameters and controlling external devices. This solves the problem of limited data transmission in existing technologies, achieving high-speed, stable bidirectional communication.

[0067] 5. Control Output: The host computer sends control commands, such as starting or stopping equipment or adjusting analog output values. After parsing the commands, the microprocessor controls the external equipment's actions through the digital output unit or outputs analog signals through the analog output unit for precise control of the external equipment. This function compensates for the shortcomings of existing PLC modules and meets complex control requirements.

[0068] 6. System Cycle and Optimization: The above process continues in a loop, with the module constantly collecting, processing, and transmitting data and responding to control commands. The module can automatically adjust its operating parameters based on feedback from the host computer or its own operating status, such as increasing the sampling frequency when there is significant signal interference, optimizing the data acquisition and control system performance, and ensuring efficient and stable operation.

[0069] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A MODBUS data acquisition module for a heat pump device, characterized in that, include: Power module for providing wide voltage input and isolated power supply; Analog input unit, used to receive analog signals from sensors; An analog-to-digital conversion module, including at least one high-speed ADC chip, is used to convert analog signals into digital signals; The microprocessor is used to control the ADC sampling timing, perform data preprocessing, and encapsulate the protocol. The MODBUS-RTU communication interface is used for bidirectional data communication with the host computer; and The input / output interface includes digital input units, digital output units, and analog output units. The analog input unit is connected to the analog-to-digital converter module; the analog-to-digital converter module is bidirectionally connected to the microprocessor; the microprocessor is connected to the communication interface and the input / output interface respectively; the power supply module provides power to the active circuit in the analog input unit, the analog-to-digital converter module, the microprocessor, the communication interface, and the input / output interface.

2. The MODBUS data acquisition module according to claim 1, characterized in that, The power supply module, analog input unit, analog-to-digital converter module, microprocessor, communication interface, and input / output interface are all integrated on a single PCB board.

3. The MODBUS data acquisition module according to claim 2, characterized in that, Integrated terminal blocks are provided on the opposite edges of the PCB board for the input and output of all external signals.

4. The MODBUS data acquisition module according to claim 3, characterized in that, The integrated terminal block includes: Power input terminal for connecting to a 9-36VDC power supply; Analog input terminal block, used to connect 4-20mA current signal and 0-10V voltage signal; Temperature sensor input terminal group, used to connect PT100 / PT1000 / NTC temperature sensor signals; Digital input terminal block; Switch output terminal group; Analog output terminal blocks; and RS-485 communication terminal, used to connect A / B signal lines.

5. The MODBUS data acquisition module according to claim 1, characterized in that, The power module includes an isolated DC-DC converter circuit and a low-noise LDO, used to provide a stable, low-noise power supply for the ADC.

6. The MODBUS data acquisition module according to claim 1, characterized in that, The analog-to-digital conversion module supports resolutions from 12 bits to 24 bits.

7. The MODBUS data acquisition module according to claim 1, characterized in that, The microprocessor supports MODBUS RTU and MODBUS TCP protocol conversion, and the communication baud rate, verification method and slave address can be set via DIP switch or software.

8. The MODBUS data acquisition module according to claim 2, characterized in that, The module is connected to a host computer or external device via an RS-485 bus to form a distributed data acquisition and control system.

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