Intelligent weighing sensor wire system adapting system

Abstract

The utility model relates to the technical field of weighing sensor, concretely is a kind of intelligent weighing sensor line system adaptation system, including 4 / 6 line system sensor interface circuit, passive RC low pass filter circuit, 3 channel ADC sampling circuit, MCU control circuit, crystal oscillator circuit, reset circuit.4 / 6 line system sensor interface circuit is compatible with 4 / 6 line system sensor and transmits signal;Passive RC low pass filter circuit filters high-frequency interference;3 channel ADC sampling circuit high-precision conversion signal;MCU control circuit identifies line system, processes data;Crystal oscillator circuit guarantees timing;Reset circuit guarantees system reset.The system realizes 4 / 6 line system sensor automatic adaptation, improves precision and reliability, reduces cost, and is applicable to weighing field.

Description

Technical Field

[0001] This utility model relates to the field of weighing sensor technology, and in particular to an intelligent weighing sensor wired adapter system. Background Technology

[0002] In weighing applications, load cells commonly come in two types: 4-wire and 6-wire. 4-wire sensors have a simple structure, but are susceptible to voltage drops during long-distance transmission. 6-wire sensors, by adding compensation lines, can offset voltage drops and improve accuracy; however, traditional adapter systems have poor compatibility, and replacing sensors with different wire types requires manual hardware or parameter adjustments, which is complex, costly, and susceptible to signal interference, failing to meet the demands for flexible and high-precision weighing. Therefore, an intelligent adapter system is urgently needed. Utility Model Content

[0003] The purpose of this invention is to overcome the problems of the prior art and provide an intelligent weighing sensor wire adaptation system that enables automatic adaptation of 4 / 6-wire sensors, improves signal acquisition accuracy and system reliability, simplifies operation, and reduces usage costs.

[0004] The above objectives are achieved through the following technical solutions:

[0005] A smart weighing sensor wire adapter system includes interconnected 4 / 6-wire sensor interface circuits, passive RC low-pass filter circuits, 3-channel ADC sampling circuits, and MCU control circuits, wherein:

[0006] The 4 / 6-wire sensor interface circuit includes 6-wire terminals (EXC+, EXC-, SEN+, SEN-, SIG+, SIG-) and a Wheatstone bridge resistor R25 consisting of four ordinary resistors (Ra, Rb, Rc, Rd), used to connect 4-wire or 6-wire load cells, provide excitation power to the sensors and transmit signals.

[0007] The passive RC low-pass filter circuit consists of resistors R22, R23, R26, R27, R28, and R29 and capacitors C49, C51, C53, C54, C55, and C56 forming a multi-stage RC filter network. Its input terminal is connected to the 4 / 6-wire sensor interface circuit, and its output terminal is connected to the 3-channel ADC sampling circuit. It is used to filter high-frequency interference in the sensor signal.

[0008] The 3-channel ADC sampling circuit includes an ADC chip U12, which is connected to the 4 / 6-wire sensor interface circuit and the MCU control circuit, and is used to convert the analog electrical signal output by the sensor into a digital signal.

[0009] The MCU control circuit includes an MCU chip U10, which communicates bidirectionally with the 3-channel ADC sampling circuit to configure the ADC working mode, identify sensor wiring, and process weight data.

[0010] Furthermore, the 6-wire terminal is compatible with both 4-wire and 6-wire load cells. If it is a 4-wire sensor, the 4-wire sensor is connected to EXC+, EXC-, SIG+, and SIG-, and the internal reference of the ADC chip U12 is used to replace the compensation line function. If it is a 6-wire sensor, the 6-wire sensor is connected to all terminals, and the compensation signal is transmitted through SEN+ and SEN-.

[0011] Furthermore, the ADC chip U12 has a built-in multiplexer that can switch between the REF2 reference source and the internal reference source to adapt to 4-wire or 6-wire sensors.

[0012] Furthermore, the ADC chip U12 is model AD7192. The AIN1 and AIN2 pins of the ADC chip U12 are respectively connected to the SIG+ and SIG- signals output by the passive RC low-pass filter circuit. The REFIN1+ and REFIN1- pins of the ADC chip U12 are respectively connected to the SEN+ and SEN- signals output by the passive RC low-pass filter circuit.

[0013] Furthermore, the MCU chip U10 is an STM32F310CXBT6. The PB9, PC14, and PC15 pins of the MCU chip U10 are connected to the SCLK, DIN, and DOUT / RDY pins of the ADC chip U12, respectively, and bidirectional communication is achieved through the SPI protocol.

[0014] Furthermore, it also includes a crystal oscillator circuit, which consists of a main clock crystal oscillator Y2, an auxiliary crystal oscillator X1, and matching capacitors C45 and C57, to provide a clock signal for the system; wherein, the main clock crystal oscillator Y2 is connected to the ADC chip U12, and the auxiliary crystal oscillator X1 is connected to the MCU chip U10.

[0015] Furthermore, the output pin of the master clock crystal Y2 is connected to the MCLK2 pin of the ADC chip U12, and the output pin of the auxiliary crystal X1 is connected to the PF0 pin of the MCU chip U10.

[0016] Furthermore, a reset circuit is connected to the MCU control circuit. The reset circuit consists of a reset chip U11, a resistor R21, and a capacitor C52 to realize system power-on reset.

[0017] Furthermore, the reset chip U11 is model SGM803B-SXN3LG / TR, one end of the resistor R21 is connected to a +3.3V power supply, and the other end is connected in series with the capacitor C52 and then grounded. The connection point of the resistor R21 and the capacitor C52 is connected to the NRST pin of the MCU chip U10.

[0018] This utility model provides an intelligent weighing sensor wire adapter system that can automatically adapt to 4 / 6-wire sensors, improving accuracy and reliability while reducing costs, making it suitable for the weighing field. Specifically:

[0019] High compatibility: With a 4 / 6-wire sensor interface circuit and a flexible reference switching mechanism, it can be adapted to 4-wire and 6-wire load cells without hardware modification, reducing equipment replacement and maintenance costs and adapting to diverse weighing needs.

[0020] High precision: The passive RC low-pass filter circuit effectively filters high-frequency interference, and the 24-bit high-precision conversion of the ADC module combined with the line compensation function reduces signal errors; the calibration algorithm of the MCU module further improves the accuracy of weight data and ensures accurate weighing results.

[0021] Intelligent: The MCU module automatically identifies the sensor wiring and switches the operating parameters, simplifying the operation process and completing the adaptation and weighing without manual intervention, thus improving ease of use and work efficiency.

[0022] High reliability: The reset circuit enables automatic reset upon power-on and in case of abnormality, the crystal oscillator circuit ensures timing accuracy, and the multi-module collaboration ensures stable system operation. It also has strong anti-interference capabilities and reduces the probability of failure. Attached Figure Description

[0023] Figure 1 This is a system block diagram of the intelligent weighing sensor wired adapter system described in this utility model;

[0024] Figure 2 This is a circuit diagram of a wired adapter system for an intelligent weighing sensor as described in this utility model. Detailed Implementation

[0025] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. The described embodiments are merely some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0026] like Figure 1 and Figure 2As shown, this solution provides an intelligent weighing sensor wire adapter system, including interconnected 4 / 6-wire sensor interface circuits, passive RC low-pass filter circuits, 3-channel ADC sampling circuits, and MCU control circuits, wherein:

[0027] The 4 / 6-wire sensor interface circuit includes 6-wire terminals EXC+, EXC-, SEN+, SEN-, SIG+, SIG- and a Wheatstone bridge resistor R25 consisting of four ordinary resistors Ra, Rb, Rc, and Rd, used to connect 4-wire or 6-wire load cells, provide excitation power to the sensors and transmit signals.

[0028] The passive RC low-pass filter circuit consists of resistors R22, R23, R26, R27, R28, and R29 and capacitors C49, C51, C53, C54, C55, and C56 forming a multi-stage RC filter network. Its input terminal is connected to the 4 / 6-wire sensor interface circuit, and its output terminal is connected to the 3-channel ADC sampling circuit. It is used to filter high-frequency interference in the sensor signal.

[0029] The 3-channel ADC sampling circuit includes an ADC chip U12, which is connected to the 4 / 6-wire sensor interface circuit and the MCU control circuit, and is used to convert the analog electrical signal output by the sensor into a digital signal.

[0030] The MCU control circuit includes an MCU chip U10, which communicates bidirectionally with the 3-channel ADC sampling circuit for configuring the ADC operating mode, identifying sensor wiring, and processing weight data. A reset circuit is connected to the MCU control circuit, consisting of a reset chip U11, resistor R21, and capacitor C52, to achieve system power-on reset.

[0031] The system also includes a crystal oscillator circuit, which consists of a main clock crystal oscillator Y2, an auxiliary crystal oscillator X1, and matching capacitors C45 and C57, providing a clock signal for the system; wherein, the main clock crystal oscillator Y2 is connected to the ADC chip U12, and the auxiliary crystal oscillator X1 is connected to the MCU chip U10.

[0032] Specifically, the 4 / 6-wire sensor interface circuit in this system includes 6-wire terminals (EXC+, EXC-, SEN+, SEN-, SIG+, SIG-) and a Wheatstone bridge resistor R25 consisting of four ordinary resistors (Ra, Rb, Rc, Rd). The 6-wire terminals are used to connect the load cell, and the Wheatstone bridge serves for signal conversion. In this embodiment, the 4 / 6-wire sensor interface circuit provides excitation power (via EXC+ and EXC-) to the 4 / 6-wire load cell and transmits the weight electrical signal (via SIG+ and SIG-). When the 6-wire sensor is working, SEN+ and SEN- transmit compensation signals to compensate for cable voltage drop. When the 4-wire sensor is connected, only EXC+, EXC-, SIG+, and SIG- need to be connected, utilizing the system's internal reference substitution compensation function to achieve compatibility.

[0033] The passive RC low-pass filter circuit described in this system consists of resistors R22, R23, R26, R27, R28, and R29, and capacitors C49, C51, C53, C54, C55, and C56, forming a multi-stage RC filter network. The resistors and capacitors are connected sequentially, with one end of each capacitor connected to the signal line and the other end connected to analog ground (AGND_2). In this embodiment, the passive RC low-pass filter circuit utilizes the frequency characteristic of capacitors to "pass high frequencies and block low frequencies." When the sensor output signal contains high-frequency interference (such as electromagnetic noise and power supply ripple) and low-frequency weight signals, the high-frequency signal can be shunted to ground through the capacitor, while the low-frequency signal is smoothly transmitted to the subsequent circuit through the resistors, thus purifying the sensor signal and providing a cleaner input for ADC sampling.

[0034] The 3-channel ADC sampling circuit in this system is based on the ADC chip U12 (model AD7192), with its pins connected to the 4 / 6-wire sensor interface circuit and the MCU control circuit. In this embodiment, the 3-channel ADC sampling circuit receives the analog electrical signals (SIG+, SIG- from the sensor and SEN+, SEN- in 6-wire mode) transmitted by the passive RC low-pass filter circuit. It converts the weak mV-level analog signals into digital signals through an internal 24-bit analog-to-digital converter. Simultaneously, it supports switching the reference source according to the sensor's wiring configuration. In 6-wire mode, the compensation signals input by SEN+ and SEN- are used as the reference to correct for the influence of cable voltage drop; in 4-wire mode, it switches to the internal reference to ensure conversion accuracy. The converted digital signal is transmitted to the MCU control circuit via the SPI interface.

[0035] The core of the MCU control circuit in this system is the MCU chip U10 (model STM32F310CXBT6), with external filter capacitors C42, C43, C44, C46, ​​C47, C48, and resistors R18 and R19. The filter capacitors ensure power supply stability. In this embodiment, the MCU control circuit sends configuration commands to the ADC sampling module via the SPI interface, such as setting the sampling rate and selecting the reference source, to control the ADC's operating mode to adapt to 4 / 6-wire sensors. After receiving the digital signal transmitted by the ADC, it runs the built-in wire identification algorithm to analyze the compensation line signals (SEN+ and SEN- corresponding signals) to determine the sensor's wire type: if the compensation line signal has no effective voltage (4-wire sensor, compensation line open circuit), the ADC switches to internal reference mode; if the compensation line signal is effective (6-wire sensor, compensation line connected), the ADC continues to use the compensation signal as the reference. Afterwards, the digital signal is filtered and calibrated (e.g., zero-point drift elimination, temperature compensation), and the weight value is calculated and output through the weighing communication module.

[0036] This embodiment programs the wire identification algorithm and weight data processing program into the MCU chip U10 (STM32F310CXBT6). By configuring ADC operating mode parameters (such as sampling rate and reference source selection logic) and SPI communication parameters (such as baud rate and data bits) in the development environment, the MCU can correctly control the ADC module to receive and process the converted data. Simultaneously, the wire identification algorithm is debugged to ensure accurate identification of 4 / 6-wire sensors and to switch operating parameters accordingly.

[0037] The crystal oscillator circuit in this system consists of a main clock crystal oscillator Y2 (24MHz), an auxiliary crystal oscillator X1 (12MHz-3.3V), and matching capacitors C45 and C57. The main clock crystal oscillator Y2 is connected to the ADC chip U12, and the auxiliary crystal oscillator X1 is connected to the MCU chip U10. The working principle of the crystal oscillator circuit in this embodiment is as follows: the main clock crystal oscillator Y2 generates a 24MHz high-frequency oscillation signal to provide the main clock for the MCU and the system, ensuring the timing accuracy of high-speed functions such as SPI communication, ADC configuration, and data processing, and ensuring accurate and timely instruction transmission and reception and data transmission for each module. The auxiliary crystal oscillator X1 generates a 12MHz low-frequency oscillation signal for timing and wake-up in the MCU's low-power mode, balancing system performance and power consumption, maintaining basic timing functions during system standby, and reducing energy consumption.

[0038] The reset circuit described in this system consists of resistor R21 and capacitor C52. One end of resistor R21 is connected to a +3.3V power supply, and the other end is connected in series with capacitor C52 and then grounded. The connection point is connected to the NRST pin of the MCU. The working principle of the reset circuit in this embodiment is as follows: When the system is powered on, capacitor C52 begins to charge. Initially, the voltage is low, triggering the MCU reset pin to start the MCU from its initial state, eliminating residual signal interference and ensuring stable system initialization. When the system malfunctions (such as program crashes or voltage fluctuations), the reset chip detects abnormal voltage or MCU operating status and automatically triggers a reset signal, which is transmitted to the MCU through the RC circuit, causing the MCU to restart and resume normal operation, improving system reliability.

[0039] This system can efficiently achieve automatic adaptation and high-precision weighing of different wire weighing sensors, meeting the compatibility, accuracy and reliability requirements of industrial weighing, electronic scales and other application scenarios.

[0040] The above description is only for illustrating the embodiments of this utility model and is not intended to limit this utility model. For those skilled in the art, any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A wired adapter system for an intelligent weighing sensor, characterized in that, This includes interconnected 4 / 6-wire sensor interface circuits, passive RC low-pass filter circuits, 3-channel ADC sampling circuits, and MCU control circuits, among which: The 4 / 6-wire sensor interface circuit includes a 6-wire terminal and a Wheatstone bridge resistor R25 consisting of four ordinary resistors, used to connect a 4-wire or 6-wire load cell, provide excitation power to the sensor and transmit signals. The passive RC low-pass filter circuit consists of resistors R22, R23, R26, R27, R28, and R29 and capacitors C49, C51, C53, C54, C55, and C56 forming a multi-stage RC filter network. Its input terminal is connected to the 4 / 6-wire sensor interface circuit, and its output terminal is connected to the 3-channel ADC sampling circuit. It is used to filter high-frequency interference in the sensor signal. The 3-channel ADC sampling circuit includes an ADC chip, which is connected to the 4 / 6-wire sensor interface circuit and the MCU control circuit, and is used to convert the analog electrical signal output by the sensor into a digital signal. The MCU control circuit includes an MCU chip that communicates bidirectionally with the 3-channel ADC sampling circuit. It is used to configure the ADC operating mode, identify sensor wiring, and process weight data.

2. The intelligent weighing sensor wired adapter system according to claim 1, characterized in that, The 6-wire terminal is compatible with both 4-wire and 6-wire load cells. If it is a 4-wire sensor, the 4-wire sensor is connected to EXC+, EXC-, SIG+, and SIG-, and the internal reference of the ADC chip is used to replace the compensation line function. If it is a 6-wire sensor, the 6-wire sensor is connected to all terminals, and the compensation signal is transmitted through SEN+ and SEN-.

3. A wired intelligent weighing sensor adapter system according to claim 1 or 2, characterized in that, The ADC chip has a built-in multiplexer that can switch between the REF2 reference source and the internal reference source to adapt to 4-wire or 6-wire sensors.

4. The intelligent weighing sensor wired adapter system according to claim 3, characterized in that, The ADC chip is model AD7192. The AIN1 and AIN2 pins of the ADC chip are respectively connected to the SIG+ and SIG- signals output by the passive RC low-pass filter circuit. The REFIN1+ and REFIN1- pins of the ADC chip are respectively connected to the SEN+ and SEN- signals output by the passive RC low-pass filter circuit.

5. The intelligent weighing sensor wired adapter system according to claim 4, characterized in that, The MCU chip is an STM32F310CXBT6. The PB9, PC14, and PC15 pins of the MCU chip are connected to the SCLK, DIN, and DOUT / RDY pins of the ADC chip, respectively, and bidirectional communication is achieved through the SPI protocol.

6. The intelligent weighing sensor wired adapter system according to claim 5, characterized in that, It also includes a crystal oscillator circuit, which consists of a master clock crystal, an auxiliary crystal, and matching capacitors C45 and C57, to provide a clock signal for the system. The master clock crystal is connected to the ADC chip, and the auxiliary crystal is connected to the MCU chip.

7. The intelligent weighing sensor wired adapter system according to claim 6, characterized in that, The output pin of the master clock crystal is connected to the MCLK2 pin of the ADC chip, and the output pin of the auxiliary crystal is connected to the PF0 pin of the MCU chip.

8. The intelligent weighing sensor wired adapter system according to claim 1, characterized in that, The MCU control circuit is connected to a reset circuit, which consists of a reset chip, a resistor R21, and a capacitor C52, to achieve system power-on reset.

9. The intelligent weighing sensor wired adapter system according to claim 8, characterized in that, The reset chip is model SGM803B-SXN3LG / TR. One end of the resistor R21 is connected to a +3.3V power supply, and the other end is connected in series with the capacitor C52 and then grounded. The connection point of the resistor R21 and the capacitor C52 is connected to the NRST pin of the MCU chip.

Images