Data acquisition device and data acquisition method

Abstract

The invention discloses a data acquisition device and method, and the device comprises a plurality of data acquisition channels, a control module and a power module, each data acquisition channel is correspondingly connected with a temperature sensor, and each data acquisition channel comprises a data acquisition module. Each data acquisition module comprises an amplification gain unit, an acquisition unit and an isolation unit; the amplification gain unit is used for shielding an interference signal of an industrial field where the temperature sensor is located and carrying out voltage stabilization amplification processing on an analog quantity signal; the acquisition unit is used for converting the acquired analog quantity signal after voltage stabilization and amplification into a digital quantity signal; and the isolation unit is used for feeding back the digital quantity signal to the control module in an isolation mode. According to the invention, each channel is provided with an independent data acquisition module, so that the problems of slow response and poor flexibility of temperature data acquisition are solved, the signal interference intensity is reduced through the amplification gain unit, the acquisition unit and the isolation unit, and the data acquisition accuracy is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of data acquisition, and in particular to a data acquisition device and a data acquisition method. Background Art

[0002] DCS (distributed control system) has been used in the field of industrial control technology for many years. Temperature data collection in industrial sites is the most complex in the entire distributed control system. RTD (resistance temperature detector) is a passive device that does not produce output independently, and its resistance increases as the sensor temperature rises.

[0003] An RTD detection module is usually used to detect the temperature data of the RTD temperature sensor on the boiler equipment in the industrial field. The RTD detection module only uses one ADC chip to detect the temperature data of the RTD temperature sensors of 8 channels in turn. The acquisition speed is slow, the signal interference intensity is large, and there is a difference between the collected temperature data and the actual temperature data, so the accuracy is low. Summary of the invention

[0004] The technical problem to be solved by the present invention is to overcome the defects of low temperature data rate, poor flexibility, large signal interference intensity and low accuracy in the prior art using traditional RTD detection modules to detect temperature, and to provide a data acquisition device and a data acquisition method.

[0005] The present invention solves the above technical problems through the following technical solutions:

[0006] In a first aspect, the present invention provides a data acquisition device, the data acquisition device comprising:

[0007] Several data acquisition channels, control modules and power modules, each of the data acquisition channels is connected to a temperature sensor, each of the data acquisition channels includes a data acquisition module, and each of the data acquisition modules includes an amplification gain unit, an acquisition unit and an isolation unit;

[0008] The data acquisition module and the control module are electrically connected to the power supply module respectively, one end of the acquisition unit is electrically connected to the amplification gain unit, and the other end of the acquisition unit is electrically connected to the isolation unit;

[0009] The power supply module is used to output a power supply voltage to the data acquisition module and the control module;

[0010] The amplification gain unit is used to shield interference signals at the industrial site where the temperature sensor is located, and to perform voltage stabilization and amplification processing on the analog signal output by the temperature sensor;

[0011] The acquisition unit is used to acquire the analog signal after voltage stabilization and amplification processing, and convert the analog signal into a digital signal;

[0012] The isolation unit is used to feed back the digital signal to the control module in an isolated manner;

[0013] The control module is used to enable the corresponding data acquisition channel according to the preset configuration information, and convert the acquired digital signal into corresponding temperature data.

[0014] Preferably, the data acquisition module further includes a first resistor, a second resistor and a third resistor;

[0015] One end of the first resistor is electrically connected to the acquisition unit, and the other end of the first resistor is electrically connected to one end of the second resistor;

[0016] The other end of the second resistor is electrically connected to the temperature sensor.

[0017] One end of the third resistor is electrically connected to the amplifying gain unit, and the other end of the third resistor is electrically connected to the temperature sensor.

[0018] Preferably, the acquisition unit includes an ADC chip.

[0019] Preferably, the power supply module includes an MCU and an FPGA, and the FPGA is used to control the ADC chip to output a constant current to maintain a constant reference voltage.

[0020] Preferably, the temperature sensor comprises an RTD temperature sensor.

[0021] Preferably, the resistance of the first resistor is 3.5 kΩ.

[0022] Preferably, the control module is also used to send the temperature data to a host computer.

[0023] Preferably, the power supply module comprises a dual redundant power supply module.

[0024] In a second aspect, the present invention provides a data acquisition method, which is implemented using the data acquisition device as described in the first aspect, comprising:

[0025] Using the control module to enable the corresponding data acquisition channel according to the preset configuration information and simultaneously collect signals from the corresponding temperature sensors to obtain a number of digital quantity signals;

[0026] The control module converts the digital signals into corresponding temperature data;

[0027] The control module is controlled to send the temperature data to a host computer for display.

[0028] Preferably, the step of using the control module to start the corresponding data acquisition channel according to the set configuration information and simultaneously collect signals from the corresponding temperature sensor to obtain a plurality of digital quantity signals includes:

[0029] The control acquisition unit obtains the analog signal after the voltage stabilization and amplification processing by the amplification gain unit;

[0030] The analog signal is converted into the digital signal by the acquisition unit.

[0031] The positive progressive effect of the present invention is that the present invention provides a data acquisition device and a data acquisition method, which solves the problems of slow response time and poor flexibility of temperature data acquisition by setting an independent data acquisition module for each channel, and reduces the signal interference intensity by amplifying the gain unit, the acquisition unit and the isolation unit, thereby improving the accuracy of temperature data acquisition. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 This is a first structural schematic diagram of the data acquisition device of Example 1 of the present invention.

[0033] Figure 2 This is a second structural schematic diagram of the data acquisition device of Example 1 of the present invention.

[0034] Figure 3 This is a flow chart of the data acquisition method of embodiment 1 of the present invention. DETAILED DESCRIPTION

[0035] The present invention is further described below by way of examples, but the present invention is not limited to the scope of the examples.

[0036] Example 1

[0037] This embodiment provides a data acquisition device, referring to Figure 1 The data acquisition device includes: a plurality of data acquisition channels, a control module 2 and a power module 3, each data acquisition channel is connected to a temperature sensor, each data acquisition channel includes a data acquisition module 1, and each data acquisition module includes an amplification gain unit 11, an acquisition unit 12 and an isolation unit 13;

[0038] The data acquisition module 1 and the control module 2 are electrically connected to the power supply module 3 respectively, one end of the acquisition unit 12 is electrically connected to the amplification gain unit 11, and the other end of the acquisition unit 12 is electrically connected to the isolation unit 13;

[0039] The power supply module 3 is used to output the power supply voltage to the data acquisition module 1 and the control module 2;

[0040] The amplification gain unit 11 is used to shield interference signals at the industrial site where the temperature sensor is located, and to perform voltage stabilization and amplification processing on the analog signal output by the temperature sensor;

[0041] The acquisition unit 12 is used to acquire the analog signal after voltage stabilization and amplification processing, and convert the analog signal into a digital signal;

[0042] The isolation unit 13 is used to feed back the digital signal to the control module in an isolated manner;

[0043] The control module 2 is used to enable the corresponding data acquisition channel according to the preset configuration information, and convert the acquired digital signal into the corresponding temperature data.

[0044] The control module 2 is also used to send the temperature data to the host computer.

[0045] In this embodiment, the data acquisition device is applied to the DCS system. By setting an independent data acquisition module 1 for each channel, the control module 2 can flexibly start 8 channels or other numbers of data acquisition channels according to the preset configuration information and the actual situation on site, which solves the defects of the traditional RTD detection module using a single ADC chip to detect the temperature data of the RTD temperature sensors of 8 channels or other numbers of channels in turn, with slow acquisition speed and poor flexibility. In addition, the amplification gain unit 11 and the isolation unit 13 are used to increase the signal anti-interference ability and improve the data acquisition accuracy.

[0046] As an optional implementation, the data acquisition module 1 further includes a first resistor, a second resistor and a third resistor;

[0047] One end of the first resistor is electrically connected to the acquisition unit 12, and the other end of the first resistor is electrically connected to one end of the second resistor;

[0048] The other end of the second resistor is electrically connected to the temperature sensor.

[0049] One end of the third resistor is electrically connected to the amplifying gain unit 11 , and the other end of the third resistor is electrically connected to the temperature sensor.

[0050] The resistance of the first resistor is 3.5 kΩ.

[0051] In this embodiment, the acquisition module 12 outputs a current source through the AIN0 pin, and after passing through the first resistor, the second resistor and the temperature sensor in sequence, the temperature sensor is connected to the AIN2 pin and the AIN5 pin of the acquisition module 12 through the amplification gain unit 11 for measurement. The first resistor is a reference precision resistor, and the second resistor and the third resistor are parasitic wiring resistances. Since the voltage drop on the second resistor affects the measurement accuracy of the temperature sensor, it is necessary to output a current source of the same magnitude as AIN0 on the AIN6 pin of the acquisition module 12 so that the voltage drops on the second resistor and the third resistor are equal, thereby offsetting each other.

[0052] When the first resistor is 3.5 kΩ, the reference voltage generated by the acquisition module 12 is: 3.5 kΩ×500 μA=1.75 V. To ensure the output accuracy of the current source, the output voltage of the power supply module 3 is required to be 0.8 V higher than the output terminal of the current source.

[0053] As an optional implementation, the acquisition unit 12 includes an ADC chip.

[0054] As an optional implementation, the power module 3 includes an MCU and an FPGA, and the FPGA is used to control the ADC chip to output a constant current to maintain a constant reference voltage.

[0055] In this embodiment, the ADC chip is on the channel card, and the control signal of the ADC chip is initiated by the MUC. In order to avoid interference of other external signals to the MCU, a reliable isolation digital device is used to isolate the control signal to obtain a single digital signal.

[0056] As an optional implementation, the temperature sensor includes an RTD temperature sensor.

[0057] In this embodiment, when the RTD temperature sensor is a three-wire RTD sensor of the PT100 model, the measured temperature range is -200°C to +800°C, the corresponding resistance value at 0°C is 100Ω, and the corresponding resistance value at 800°C is 384.9Ω. When the constant current source output by the ADC chip is 500uA, the voltage signal collected from the output of the RTD temperature sensor is: 500μA×384.9Ω=192.5mV. The gain is set to 8, and the analog signal is amplified to 1.54V by the amplification gain unit 11. The reference voltage generated by the first resistor is greater than 1.54*1.1V (it is recommended to leave 10% redundancy), 1.54V*1.1 / 500μA=3387Ω.

[0058] As an optional implementation, the power supply module 3 includes a dual redundant power supply module.

[0059] In this embodiment, the power supply module 3 is a dual redundant power supply. In order to protect the internal components and channel safety of the card, the dual redundant power supply adopts a method of isolating the power supply and the system power supply. Since the principle of first protection and then filtering is adopted for the power supply part, the power supply module 3 can include a hot-swappable module circuit, an EMI filtering circuit and a DC-DC conversion circuit to achieve surge, overvoltage and overcurrent protection and EMI filtering.

[0060] Reference Figure 2 , the FPGA and MCU architecture are used to obtain the resistance signal collected by the 3-wireRrtd temperature sensor. The data acquisition device includes FPGA, MCU, ADC chip, isolated digital device, DC-DC power supply module and amplifier gain protection circuit. FPGA controls the ADC chip to provide a constant current source to obtain a stable reference voltage. The resistance signal collected by the on-site RTD sensor enters the ADC chip as a voltage signal through the amplifier gain protection circuit, and then is parsed into a digital signal by the ADC chip, and is passed to the FPGA through the isolated digital device, and then to the MCU. The MCU is then parsed into temperature data and transmitted to the host computer. This method solves the problems of slow response, low accuracy and poor flexibility of temperature data acquisition in industrial sites through the configuration of each channel ADC chip.

[0061] In this embodiment, the data acquisition device solves the problems of slow response and poor flexibility of temperature data acquisition by setting an independent data acquisition module for each channel, and reduces the signal interference intensity through the amplification gain unit, acquisition unit and isolation unit to improve data acquisition accuracy.

[0062] Example 2

[0063] This embodiment provides a data collection method, such as Figure 3 As shown, the data acquisition device in Example 1 is used to implement the method, including:

[0064] S210, using the control module to enable corresponding data acquisition channels according to preset configuration information and simultaneously collect signals from corresponding temperature sensors to obtain a number of digital signals;

[0065] S220, converting a number of digital signals into corresponding temperature data through a control module;

[0066] S230, the control module sends the temperature data to the host computer for display.

[0067] Wherein, step S210 specifically includes:

[0068] S211, controlling the acquisition unit to obtain the analog signal after the voltage stabilization and amplification processing by the amplification gain unit;

[0069] S212, controlling the acquisition unit to obtain the analog signal after the voltage stabilization and amplification processing by the amplification gain unit.

[0070] Specifically, the data acquisition device is applied to the DCS system. By setting an independent data acquisition module for each channel, the control module can flexibly start 8 channels or other numbers of data acquisition channels according to the preset configuration information and the actual situation on site, which solves the defects of the traditional RTD detection module that only uses one ADC chip to detect the temperature data of the RTD temperature sensors of 8 channels or other numbers of channels in turn, with slow acquisition speed and poor flexibility. In addition, the amplification gain unit 11 and the isolation unit are used to increase the signal anti-interference ability and improve the data acquisition accuracy.

[0071] In this embodiment, the control module of the data acquisition device is used to enable the corresponding data acquisition channel according to the preset configuration information and simultaneously acquire signals from the corresponding temperature sensors to obtain a number of digital signals, thereby solving the problems of slow response and poor flexibility of temperature data acquisition; the signal interference intensity is reduced by amplifying the gain unit, the acquisition unit and the isolation unit, thereby improving the accuracy of data acquisition.

[0072] Although the specific embodiments of the present invention are described above, it should be understood by those skilled in the art that this is only for illustration and the protection scope of the present invention is defined by the appended claims. Those skilled in the art may make various changes or modifications to these embodiments without departing from the principles and essence of the present invention, but these changes and modifications all fall within the protection scope of the present invention.

Claims

1. A data acquisition device, characterized in that: The data acquisition device comprises: a plurality of data acquisition channels, a control module and a power supply module, each of the data acquisition channels is connected to a corresponding temperature sensor, each of the data acquisition channels comprises a data acquisition module, and each of the data acquisition modules comprises an amplification gain unit, an acquisition unit and an isolation unit; The data acquisition module and the control module are electrically connected to the power supply module respectively, one end of the acquisition unit is electrically connected to the amplification gain unit, and the other end of the acquisition unit is electrically connected to the isolation unit; The power supply module is used to output a power supply voltage to the data acquisition module and the control module; The amplification gain unit is used to shield interference signals at the industrial site where the temperature sensor is located, and to perform voltage stabilization and amplification processing on the analog signal output by the temperature sensor; The acquisition unit is used to acquire the analog signal after voltage stabilization and amplification processing, and convert the analog signal into a digital signal; The isolation unit is used to feed back the digital signal to the control module in an isolated manner; The control module is used to enable the corresponding data acquisition channel according to the preset configuration information, and convert the acquired digital signal into corresponding temperature data.

2. The data acquisition device according to claim 1, characterized in that: The data acquisition module also includes a first resistor, a second resistor and a third resistor; One end of the first resistor is electrically connected to the acquisition unit, and the other end of the first resistor is electrically connected to one end of the second resistor; The other end of the second resistor is electrically connected to the temperature sensor. One end of the third resistor is electrically connected to the amplifying gain unit, and the other end of the third resistor is electrically connected to the temperature sensor.

3. The data acquisition device according to claim 1, characterized in that: The acquisition unit includes an ADC chip.

4. The data acquisition device according to claim 3, characterized in that: The power supply module includes an MCU and an FPGA, and the FPGA is used to control the ADC chip to output a constant current to maintain a constant reference voltage.

5. The data acquisition device according to claim 1, characterized in that: The temperature sensor includes an RTD temperature sensor.

6. The data acquisition device according to claim 2, characterized in that: The resistance of the first resistor is 3.5 kΩ.

7. The data acquisition device according to claim 1, characterized in that: The control module is also used to send the temperature data to a host computer.

8. The data acquisition device according to claim 1, characterized in that: The power supply module includes a dual redundant power supply module.

9. A data collection method, characterized in that: The method is implemented by using the data acquisition device according to any one of claims 1 to 8, comprising: Using the control module to enable the corresponding data acquisition channel according to the preset configuration information and simultaneously collect signals from the corresponding temperature sensors to obtain a number of digital quantity signals; The control module converts the digital signals into corresponding temperature data; The control module is controlled to send the temperature data to a host computer for display.

10. The data collection method according to claim 9, characterized in that: The step of using the control module to start the corresponding data acquisition channel according to the set configuration information and simultaneously collect signals from the corresponding temperature sensor to obtain a plurality of digital quantity signals includes: The control acquisition unit obtains the analog signal after the voltage stabilization and amplification processing by the amplification gain unit; The analog signal is converted into the digital signal by the acquisition unit.

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