A signal acquisition device

Abstract

This invention discloses a signal acquisition device, relating to the field of detection. The device connects to the object being detected via a connecting cable and includes a first analog-to-digital converter (ADC), a first selection module, a processing module, and a current sampling resistor. When the received output signal from the object being detected is a digital input signal, the first selection module attenuates the digital input signal and transmits the attenuated signal to the first ADC. When the received output signal from the object being detected is an analog input signal, the first selection module transmits the analog input signal to the first ADC. This realizes the sampling process for both analog and digital input signals, unifying the sampling circuits for two different signals into a single circuit. The circuit structure is simple, improving the degree of material normalization, enhancing the flexibility of signal acquisition, reducing production and development costs, minimizing processing and spare parts work, and improving the efficiency of signal acquisition.

Description

Technical Field

[0001] This invention relates to the field of detection, and in particular to a signal acquisition device. Background Technology

[0002] With the continuous development of automatic control technology, safety instrumented systems have been widely used in various control systems. They can monitor various faults or dangerous situations that occur during the operation of the control system by acquiring analog or digital signals. Generally, safety instrumented systems usually have two types of input signals: 4-20mA analog input signals and digital input signals. The acquisition process of these two types of input signals is an important part of the safety instrumented system.

[0003] In existing technologies, the design of acquisition circuits for analog input signals and digital input signals is different. For acquisition circuits for analog input signals, please refer to [reference needed]. Figure 1 , Figure 1 This is an analog input signal acquisition circuit in the prior art. The circuit includes a first analog-to-digital converter, a second analog-to-digital converter, a current sampling resistor R1, a diagnostic resistor R2, an isolation module, an FPGA (Field Programmable Gate Array) and an MCU (Microcontroller Unit). A 24V power supply connects the field instrument being detected to the acquisition circuit in series via a connecting cable.

[0004] For the acquisition circuit of digital input signals, please refer to [reference needed]. Figure 2 , Figure 2 This is a digital input signal acquisition circuit in the prior art. The circuit includes a first analog-to-digital converter, a second analog-to-digital converter, a voltage divider resistor, a current sampling resistor R1, a diagnostic resistor R2, an isolation module, an FPGA, and an MCU. The field instrument being detected is connected in parallel with the current sampling resistor R1 via a connecting cable.

[0005] In the existing technology, the acquisition of analog input signals and digital input signals are two different processes, which require two different acquisition circuits. The circuit structure is complex, and the acquisition process for different input signals is complicated, with low flexibility, which greatly increases production costs and reduces work efficiency. Summary of the Invention

[0006] The purpose of this invention is to provide a signal acquisition device that realizes the sampling process of analog and digital input signals, unifies the sampling circuits for the two different signals into a single circuit, simplifies the circuit structure, improves the degree of material normalization, enhances the flexibility of signal acquisition, reduces production and development costs, reduces processing and spare parts work, and improves the efficiency of signal acquisition.

[0007] To solve the above-mentioned technical problems, the present invention provides a signal acquisition device, which is connected to the detection object via a connecting cable, and includes:

[0008] The first analog-to-digital converter has its analog input terminal connected to the second terminal of the first selection module and its digital input terminal connected to the processing module.

[0009] The first selection module has its first terminal connected to the first terminal of the current sampling resistor. When the received output signal of the detected object is a digital input signal, it attenuates the digital input signal and transmits the attenuated signal to the first analog-to-digital converter. When the received output signal of the detected object is an analog input signal, it transmits the analog input signal to the first analog-to-digital converter.

[0010] The second terminal of the current sampling resistor is grounded.

[0011] The processing module is used to receive the output signal of the first analog-to-digital converter.

[0012] Preferably, it further includes:

[0013] The second analog-to-digital converter has its analog input terminal connected to the second terminal of the second selection module, and its digital input terminal connected to the processing module.

[0014] The diagnostic resistor has its first end connected to the second end of the current sampling resistor and the first end of the second selection module, respectively, and its second end is grounded.

[0015] The second selection module is used to attenuate the signal at the second end of the current sampling resistor and transmit the attenuated signal to the second analog-to-digital converter when the received output signal of the detected object is a digital input signal; and to transmit the signal at the second end of the current sampling resistor to the first analog-to-digital converter when the received output signal of the detected object is an analog input signal.

[0016] Preferably, the processing module is further configured to:

[0017] Detect the first voltage across the current sampling resistor and the second voltage across the diagnostic resistor;

[0018] Determine whether the ratio of the first voltage to the second voltage is equal to the ratio of the first resistance value of the current sampling resistor to the second resistance value of the diagnostic resistor;

[0019] If so, then it is determined that the current sampling resistor is not faulty.

[0020] Preferably, when the received output signal of the detected object is an analog input signal, after determining that the current sampling resistor is not faulty, the processing module is further configured to:

[0021] The current value flowing through the current sampling resistor is detected;

[0022] Determine whether the current value is lower than a first preset value;

[0023] If the current value is lower than the first preset value, it is determined that the connecting cable is faulty and in an open circuit state.

[0024] Determine whether the current value is greater than a second preset value, wherein the second preset value is greater than the first preset value;

[0025] If the current value is greater than the second preset value, it is determined that the connecting cable is faulty and in a short circuit state.

[0026] Preferably, when the received output signal of the detected object is a digital input signal, after determining that the current sampling resistor is not faulty, the processing module is further configured to:

[0027] The voltage across the current sampling resistor is detected based on the first analog-to-digital converter and the second analog-to-digital converter;

[0028] The digital input signal is determined as either normally open or normally closed based on the voltage across the current sampling resistor.

[0029] Preferably, when the digital input signal is a normally open signal, it further includes a first detection resistor connected in parallel across the detection object, and the processor is further configured to:

[0030] The first voltage across the current sampling resistor is detected based on the first analog-to-digital converter and the second analog-to-digital converter;

[0031] The first voltage is used to determine whether the connecting cable is in a faulty state.

[0032] Preferably, when the digital input signal is a normally closed signal, a second detection resistor is further included in series between the detection object and the connecting cable, and the processor is further configured to:

[0033] The second voltage across the current sampling resistor is detected based on the first analog-to-digital converter and the second analog-to-digital converter;

[0034] The second voltage is used to determine whether the connecting cable is in a faulty state.

[0035] Preferably, determining whether the connecting cable is in a fault state based on the first voltage includes:

[0036] When the first voltage is equal to the first preset voltage, it is determined that the connecting cable is not faulty. The first preset voltage is the product of the voltage value of the power supply and the first ratio. The first ratio is the sum of the first resistance value divided by the first resistance value, the second resistance value and the resistance value of the first detection resistor.

[0037] When the first voltage is equal to the second preset voltage, it is determined that the connecting cable is faulty and in a short circuit state. The second preset voltage is the product of the voltage value of the power supply and the second ratio. The second ratio is the first resistance value divided by the sum of the first resistance value and the second resistance value.

[0038] When the first voltage is zero, it is determined that the connecting cable is faulty and in an open circuit state.

[0039] Preferably, determining whether the connecting cable is in a fault state based on the second voltage includes:

[0040] When the second voltage is equal to the third preset voltage, it is determined that the connecting cable is not faulty. The third preset voltage is the product of the voltage value of the power supply and the third ratio. The third ratio is the sum of the first resistance value divided by the first resistance value, the second resistance value and the resistance value of the second detection resistor.

[0041] When the second voltage is equal to the second preset voltage, it is determined that the connecting cable is faulty and in a short circuit state. The second preset voltage is the product of the voltage value of the power supply and the second ratio. The second ratio is the first resistance value divided by the sum of the first resistance value and the second resistance value.

[0042] When the second voltage is zero, it is determined that the connecting cable is faulty and in an open circuit state.

[0043] Preferably, the first selection module includes:

[0044] A first switch, an attenuator, a second switch, and a fixed resistor are connected in series. The first switch and the attenuator are connected in series, and the second switch and the fixed resistor are connected in parallel. The first terminal of the parallel circuit is connected to the first terminal of the current sampling resistor, and the second terminal is connected to the analog terminal of the first analog-to-digital converter.

[0045] The first switch is used to close when the output signal of the detected object is a digital input signal, so that the attenuator attenuates the digital input signal and transmits the attenuated signal to the first analog-to-digital converter.

[0046] The second switch is used to close when the received output signal of the detected object is an analog input signal, so that the analog input signal is transmitted to the first analog-to-digital converter.

[0047] This invention provides a signal acquisition device that connects to a detection object via a connecting cable. The device includes a first analog-to-digital converter (ADC), a first selection module, a processing module, and a current sampling resistor. When the received output signal from the detection object is a digital input signal, the first selection module attenuates the digital input signal and transmits the attenuated signal to the first ADC. When the received output signal from the detection object is an analog input signal, the first selection module transmits the analog input signal to the first ADC. This realizes the sampling process for both analog and digital input signals, unifying the sampling circuits for two different signals into a single circuit. The circuit structure is simple, improving the degree of material normalization, enhancing the flexibility of signal acquisition, reducing production and development costs, minimizing processing and spare parts work, and improving the efficiency of signal acquisition. Attached Figure Description

[0048] To more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the prior art and embodiments 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.

[0049] Figure 1 This is an analog input signal acquisition circuit in the prior art;

[0050] Figure 2 This is a digital input signal acquisition circuit in the prior art;

[0051] Figure 3 This is a schematic diagram of the structure of a signal acquisition device provided by the present invention;

[0052] Figure 4 This is a schematic diagram of another signal acquisition device provided by the present invention;

[0053] Figure 5 This is a schematic diagram of another signal acquisition device provided by the present invention;

[0054] Figure 6 This is a schematic diagram of another signal acquisition device provided by the present invention;

[0055] Figure 7 This is a schematic diagram of another signal acquisition device provided by the present invention. Detailed Implementation

[0056] The core of this invention is to provide a signal acquisition device that realizes the sampling process of analog input signals and digital input signals, unifies the sampling circuits for the two different signals into a single circuit, simplifies the circuit structure, improves the degree of material normalization, enhances the flexibility of signal acquisition, and at the same time reduces production and development costs, reduces processing and spare parts work, and improves the efficiency of signal acquisition.

[0057] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, 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, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0058] The calibration method and related components provided by this invention are mainly applied to SIS (Safety Instrument System). This application does not make any special limitations on the specific type and implementation of SIS. The input signals of the safety instrument system are usually 4-20mA analog input signals and digital input signals. Detailed implementation methods are described below.

[0059] Please refer to Figure 3 , Figure 3 This is a schematic diagram of the structure of a signal acquisition device provided by the present invention;

[0060] A signal acquisition device, which is connected to a detection object via a connecting cable, includes:

[0061] The first analog-to-digital converter 1 has its analog input terminal connected to the second terminal of the first selection module 2, and its digital input terminal connected to the processing module 3.

[0062] The first selection module 2 has its first terminal connected to the first terminal of the current sampling resistor R1. When the received output signal of the detected object is a digital input signal, it attenuates the digital input signal and transmits the attenuated signal to the first analog-to-digital converter 1; when the received output signal of the detected object is an analog input signal, it transmits the analog input signal to the first analog-to-digital converter 1.

[0063] The second terminal of the current sampling resistor R1 is grounded;

[0064] Processing module 3 is used to receive the output signal of the first analog-to-digital converter 1.

[0065] Specifically, the object being detected is connected to the signal acquisition device via a connecting cable. The object being detected transmits its output signal to the signal acquisition device. When the received output signal from the object being detected is a digital input signal, the first selection module 2 attenuates the digital input signal before transmitting it to the first analog-to-digital converter 1. When the received output signal from the object being detected is an analog input signal, the analog input signal is directly transmitted to the first analog-to-digital converter 1. The first analog-to-digital converter 1 converts the output signal from the first selection module 2 from analog to digital and transmits the converted digital signal to the processing module 3 for subsequent recording and analysis operations.

[0066] Understandably, for analog input signals, the first analog-to-digital converter 1 can directly receive and perform analog-to-digital conversion; however, for digital input signals, since the high-level state of a digital input signal is usually a very large signal, it is generally outside the receiving range of the first analog-to-digital converter 1. Therefore, the first analog-to-digital converter 1 cannot directly receive the digital input signal. Thus, the first selection module 2 needs to attenuate the digital input signal to ensure that the attenuated signal is within the receiving range of the first analog-to-digital converter 1, allowing for analog-to-digital conversion. This application does not impose specific limitations on the specific implementation and configuration of the first selection module 2; adjustments can be made according to the actual application environment and specific needs.

[0067] Specifically, there are many ways to determine whether the received output signal of the object being tested is an analog input signal or a digital input signal. One approach is to manually determine the output signal of the field instrument used as the object being tested, and then directly determine the operating mode of the first selection module 2 based on the field instrument used. Another approach is to add a monitoring module for the output signal of the object being tested, determine the signal through the monitoring module, and send the monitoring result to the processing module 3. The processing module 3 then controls the first selection module 2 to select the corresponding operating mode based on the monitoring result. This application does not impose any specific limitations on the specific implementation method for determining whether the received output signal of the object being tested is an analog input signal or a digital input signal.

[0068] Specifically, there are various options for the specific types and implementation methods of the processing module 3, the first analog-to-digital converter 1, and the current sampling resistor R1, and this application does not impose any particular limitations here. The processing module 3 can be an MCU and / or an FPGA, or other processors, etc.; the current sampling resistor R1 can be a common resistor, which is low in cost and easy to implement; the specific selection of the first analog-to-digital converter 1, etc., is not particularly limited here. It should be noted that the signal acquisition device includes, but is not limited to, the above-mentioned modules. The description of the signal acquisition device in this application does not constitute a limitation on the signal acquisition device, and it may include more or fewer components than those described above, such as an isolation module.

[0069] It is understandable that during signal acquisition, the first analog-to-digital converter 1 needs to acquire the signal of the object being detected by detecting the voltage signal across the current sampling resistor R1. Therefore, the signal acquisition device needs to include the current sampling resistor R1 to ensure the normal operation of the first analog-to-digital converter 1. Generally, there are various options for the connection between the object being detected and the signal acquisition device. This application does not impose any particular limitation here. For different types or structures of objects being detected, the specific connection method between them and the signal acquisition device will not be exactly the same and can be adjusted according to the actual application environment and actual needs.

[0070] This invention provides a signal acquisition device that connects to a detection object via a connecting cable. The device includes a first analog-to-digital converter 1, a first selection module 2, a processing module 3, and a current sampling resistor R1. When the received output signal from the detection object is a digital input signal, the first selection module 2 attenuates the digital input signal and transmits the attenuated signal to the first analog-to-digital converter 1. When the received output signal from the detection object is an analog input signal, the first selection module 2 transmits the analog input signal to the first analog-to-digital converter 1. This realizes the sampling process for both analog and digital input signals, unifying the sampling circuits for two different signals into a single circuit. The circuit structure is simple, improving the degree of material normalization, enhancing the flexibility of signal acquisition, reducing production and development costs, minimizing processing and spare parts work, and improving the efficiency of signal acquisition.

[0071] Based on the above embodiments,

[0072] Please refer to Figure 4 , Figure 4 This is a schematic diagram of another signal acquisition device provided by the present invention; Figure 4 It is a specific circuit implementation of a signal acquisition device when the connected detection object is an analog input signal;

[0073] Please refer to Figure 5 , Figure 5 This is a schematic diagram of another signal acquisition device provided by the present invention; Figure 5 It is a specific circuit implementation of a signal acquisition device when the connected detection object is a digital input signal;

[0074] As a preferred embodiment, it further includes:

[0075] The second analog-to-digital converter has its analog input terminal connected to the second terminal of the second selection module and its digital input terminal connected to the processing module 3.

[0076] The diagnostic resistor R2 has its first end connected to the second end of the current sampling resistor R1 and the first end of the second selection module, and its second end is grounded.

[0077] The second selection module is used to attenuate the signal at the second end of the current sampling resistor R1 when the received output signal of the detected object is a digital input signal, and transmit the attenuated signal to the second analog-to-digital converter; when the received output signal of the detected object is an analog input signal, it transmits the signal at the second end of the current sampling resistor R1 to the first analog-to-digital converter 1.

[0078] Considering the need for diagnostic testing of the signal acquisition device during application, a diagnostic resistor R2, a second analog-to-digital converter (ADC), and a second selection module are added. The second selection module receives the signal from the second terminal of the current sampling resistor R1. When the output signal of the detected object received by the signal acquisition device is a digital input signal, the second selection module attenuates the signal from the second terminal of the current sampling resistor R1 before transmitting it to the second ADC. When the output signal of the detected object received by the signal acquisition device is an analog input signal, the analog input signal can be directly transmitted to the second ADC. The second ADC converts the output signal of the second selection module from analog to digital and transmits the converted digital signal to the processing module 3 for subsequent recording and analysis.

[0079] It is understandable that when the output signal of the detected object received by the signal acquisition device is a digital input signal, the signal at the second end of the current sampling resistor R1 corresponds to this digital input signal. When the digital input signal is in a high-level state, the signal at the second end of the current sampling resistor R1 is also a relatively large signal, which is outside the receiving range of the second analog-to-digital converter (ADC). Therefore, the second ADC cannot directly receive the digital input signal. Thus, the second selection module needs to attenuate the digital input signal to ensure that the attenuated signal is within the receiving range of the second ADC, allowing for analog-to-digital conversion. This application does not impose specific limitations on the specific implementation and settings of the second selection module; adjustments can be made according to the actual application environment and specific needs.

[0080] Specifically, this application does not impose any particular limitations on the specific type and implementation method of the second analog-to-digital converter and the diagnostic resistor R2, which can be adjusted according to the actual application environment and actual needs. The diagnostic resistor R2 can be a common resistor, which is low in cost and easy to implement. This application also does not impose any particular limitations on the specific diagnostic process and implementation method of the signal acquisition device.

[0081] Considering the need for diagnostics of the signal acquisition device during application, a diagnostic resistor R2, a second analog-to-digital converter, and a second selection module were added. The second selection module transmits the signal to the second terminal of the current sampling resistor R1, ensuring the normal operation of the second analog-to-digital converter. Whether it is an analog or digital input signal, the correct diagnostics of the entire signal acquisition device can be ensured, further improving the degree of material normalization, enhancing the flexibility of signal acquisition, reducing production and development costs, reducing processing and spare parts work, and improving the efficiency of signal acquisition.

[0082] In a preferred embodiment, processing module 3 is further configured to:

[0083] The first voltage across the current sampling resistor R1 and the second voltage across the diagnostic resistor R2 are detected.

[0084] Determine whether the ratio of the first voltage to the second voltage is equal to the ratio of the first resistance value of the current sampling resistor R1 to the second resistance value of the diagnostic resistor R2;

[0085] If so, then the current sampling resistor R1 is determined to be fault-free.

[0086] This embodiment describes a specific method for diagnosing the current sampling resistor R1 in a signal acquisition device. The diagnosis of the current sampling resistor R1 is achieved by comparing the voltage ratio of the current sampling resistor R1 to the diagnostic resistor R2 and their resistance ratio. If the voltage ratio and resistance ratio of the current sampling resistor R1 and the diagnostic resistor R2 are the same, it proves that the current sampling resistor R1 is not faulty and can perform voltage division normally. If the voltage ratio and resistance ratio of the current sampling resistor R1 and the diagnostic resistor R2 are not the same, it proves that the current sampling resistor R1 is faulty, requiring subsequent replacement or troubleshooting. When the resistance values ​​of the current sampling resistor R1 and the diagnostic resistor R2 are the same, if the current sampling resistor R1 is not faulty, the voltage at the first terminal of the current sampling resistor R1 is twice the voltage at the second terminal of the current sampling resistor R1. If the current sampling resistor R1 is faulty, the voltage at the first terminal of the current sampling resistor R1 is not twice the voltage at the second terminal of the current sampling resistor R1.

[0087] It is understood that the detection of the voltage across the current sampling resistor R1 and the diagnostic resistor R2 is achieved through the first analog-to-digital converter 1 and the second analog-to-digital converter. The resistance values ​​of the current sampling resistor R1 and the diagnostic resistor R2 can be preset in the processing module 3 and adjusted as the current sampling resistor R1 and the diagnostic resistor R2 change, or they can be manually entered during the application. There are many ways to implement the detection process of the voltage across the current sampling resistor R1 and the diagnostic resistor R2, and the determination process of the resistance values ​​of the current sampling resistor R1 and the diagnostic resistor R2. This application does not make any special limitation here.

[0088] By comparing the voltage ratio and resistance ratio of the current sampling resistor R1 and the diagnostic resistor R2, the diagnostic process of the current sampling resistor R1 is realized. This method is simple, fast, and easy to implement. It can effectively determine whether the current sampling resistor R1 is faulty, so as to ensure the accuracy of subsequent normal acquisition work or troubleshooting operations. This further improves the accuracy of the acquisition results of the signal acquisition device, reduces errors, and ensures the accuracy and reliability of the acquisition results.

[0089] In a preferred embodiment, when the received output signal of the detected object is an analog input signal, after determining that the current sampling resistor R1 is not faulty, the processing module 3 is further used to:

[0090] Detect the current value flowing through the current sampling resistor R1;

[0091] Determine if the current value is lower than the first preset value;

[0092] If the current value is lower than the first preset value, it is determined that the connecting cable is faulty and in an open circuit state.

[0093] Determine whether the current value is greater than the second preset value; if the second preset value is greater than the first preset value.

[0094] If the current value is greater than the second preset value, it is determined that the connecting cable is faulty and in a short circuit state.

[0095] This embodiment describes a specific method for diagnosing connecting cables when the received output signal of the object being detected is an analog input signal. Assuming the current sampling resistor R1 is functioning correctly, the current flowing through R1 is detected, and the connecting cable is diagnosed by comparing this current value with a preset value. When the connecting cable is short-circuited, the voltage flowing through the current sampling resistor R1 will be very high; when the connecting cable is open-circuited, the current flowing through R1 will be very low, close to zero.

[0096] It is understood that the first preset value and the second preset value can be pre-entered into the processing module 3. The first preset value is a smaller value, such as 1.4mA; the second preset value is a larger value, such as 23mA. This application does not make any special restrictions on the specific values ​​and setting methods of the first preset value and the second preset value.

[0097] Specifically, when the output signal of the detected object is an analog input signal, there are many ways to diagnose the connecting cable. This embodiment only provides one specific implementation method, which can be adjusted according to the actual application environment and actual needs. This application does not make any special limitation on the specific implementation method.

[0098] This embodiment describes a specific method for diagnosing connecting cables when the received output signal of the object being detected is an analog input signal. The diagnostic process for the connecting cables is achieved by detecting the current value flowing through the current sampling resistor R1. This method is simple, fast, and easy to implement, and can effectively determine whether the connecting cable has a fault and the specific nature of the fault. This ensures accurate subsequent data acquisition or troubleshooting operations, further improving the accuracy of the signal acquisition device's acquisition results, reducing errors, and guaranteeing the accuracy and reliability of the acquisition results.

[0099] In a preferred embodiment, when the received output signal of the detected object is a digital input signal, after determining that the current sampling resistor R1 is not faulty, the processing module 3 is further configured to:

[0100] The voltage across the current sampling resistor R1 is detected by the first analog-to-digital converter 1 and the second analog-to-digital converter;

[0101] The voltage across the current sampling resistor R1 determines whether the digital input signal is normally open or normally closed.

[0102] It is understandable that when the output signal of the detected object is a digital input signal, there are two possibilities for the digital input signal. Therefore, it is necessary to determine whether the digital input signal is normally open or normally closed in order to facilitate the subsequent diagnostic process. There are many ways to determine whether the digital input signal is normally open or normally closed, and this application does not make any special restrictions here.

[0103] Specifically, the voltage across the current sampling resistor R1 can be detected. When the digital input signal is normally open, the voltage across the current sampling resistor R1 is close to zero. When the digital input signal is normally closed, the current sampling resistor R1 and the diagnostic resistor R2 together form a voltage divider circuit, and the voltage across the current sampling resistor R1 should be the normal voltage divider result. When the power supply is 24V, the voltage across the current sampling resistor R1 should be... In this formula, R1 represents the resistance value of the current sampling resistor R1, and R2 represents the resistance value of the diagnostic resistor R2.

[0104] When the received output signal of the detected object is a digital input signal, a process for determining whether the digital input signal is normally open or normally closed is added. This method in this embodiment is simple, fast, and easy to implement, effectively determining whether the digital input signal is normally open or normally closed, so that subsequent diagnosis can be performed according to different situations of the digital input signal, ensuring the correctness of the subsequent diagnostic process, further improving the accuracy of the acquisition results of the signal acquisition device, reducing errors, and ensuring the accuracy and reliability of the acquisition results.

[0105] Please refer to Figure 6 , Figure 6 This is a schematic diagram of another signal acquisition device provided by the present invention;

[0106] In a preferred embodiment, when the digital input signal is a normally open signal, a first detection resistor R4 connected in parallel across the detection object is also included. The processor is further configured to:

[0107] The first voltage across the current sampling resistor R1 is detected by the first analog-to-digital converter 1 and the second analog-to-digital converter 2.

[0108] Determine whether the connecting cable is in a faulty state based on the first voltage.

[0109] Considering the diagnostic process of the signal acquisition device when the digital input signal is normally open, a first detection resistor R4 is added in parallel across the two ends of the object being detected. The first voltage across the current sampling resistor R1 at this time can be used to determine whether the connecting cable is in a faulty state. The voltage across the current sampling resistor R1 will be different for different states of the connecting cable.

[0110] Specifically, there are many ways to determine the current state of the connecting cable based on the first voltage. The choice can be made based on the different current sampling resistor R1 and the first detection resistor R4, or other practical factors. This application does not impose any particular limitations here. Similarly, this application does not impose any particular limitations on the specific value and implementation method of the first detection resistor R4.

[0111] Considering the diagnostic process of the signal acquisition device when the digital input signal is normally open, a first detection resistor R4 is added in parallel across the two ends of the object being detected. The first voltage across the current sampling resistor R1 at this time is used to determine whether the connecting cable is in a faulty state, thus realizing the diagnosis of the connecting cable. This method is simple, fast, easy to implement, and has a simple circuit structure. It can effectively determine whether the connecting cable is faulty, so as to ensure the accuracy of subsequent normal acquisition work or troubleshooting operations, and further ensure the accuracy and reliability of the acquisition results.

[0112] Please refer to Figure 7 , Figure 7 This is a schematic diagram of another signal acquisition device provided by the present invention.

[0113] In a preferred embodiment, when the digital input signal is a normally closed signal, a second detection resistor R3 is further included, connected in series between the detection object and the connecting cable. The processor is also used to:

[0114] The second voltage across the current sampling resistor R1 is detected by the first analog-to-digital converter 1 and the second analog-to-digital converter 2.

[0115] The second voltage is used to determine whether the connecting cable is in a faulty state.

[0116] Considering the diagnostic process of the signal acquisition device when the digital input signal is a normally closed signal, a second detection resistor R3 is added in series between the detection object and the connecting cable. The second voltage across the current sampling resistor R1 at this time can be used to determine whether the connecting cable is in a faulty state. The voltage across the current sampling resistor R1 will be different for different states of the connecting cable.

[0117] Specifically, there are many ways to determine the current state of the connecting cable based on the second voltage. The method can be chosen based on the difference between the current sampling resistor R1 and the second detection resistor R3, or other practical factors. This application does not impose any particular limitations on these methods. Similarly, this application does not impose any particular limitations on the specific value and implementation method of the second detection resistor R3.

[0118] Considering the diagnostic process of the signal acquisition device when the digital input signal is normally closed, a second detection resistor R3 is added in series between the detection object and the connecting cable. The second voltage across the current sampling resistor R1 at this time is used to determine whether the connecting cable is in a faulty state, thus realizing the diagnosis of the connecting cable. This method is simple, fast, easy to implement, and has a simple circuit structure. It can effectively determine whether the connecting cable is faulty, so as to ensure the accuracy of subsequent normal acquisition work or troubleshooting operations, and further ensure the accuracy and reliability of the acquisition results.

[0119] As a preferred embodiment, determining whether the connecting cable is in a fault state based on a first voltage includes:

[0120] When the first voltage is equal to the first preset voltage, it is determined that there is no fault in the connecting cable. The first preset voltage is the product of the voltage value of the power supply and the first ratio. The first ratio is the sum of the first resistance value divided by the first resistance value, the second resistance value and the resistance value of the first detection resistor R4.

[0121] When the first voltage is equal to the second preset voltage, it is determined that the connecting cable is faulty and in a short circuit state. The second preset voltage is the product of the voltage value of the power supply and the second ratio. The second ratio is the first resistance value divided by the sum of the first resistance value and the second resistance value.

[0122] When the first voltage is zero, it is determined that the connecting cable is faulty and in an open circuit state.

[0123] Specifically, when the first voltage equals the first preset voltage, the connecting cable is fault-free. The first preset voltage is the resistance value of the current sampling resistor R1 under normal voltage division. When the power supply is 24V, the first preset voltage is... In this formula, R1 represents the resistance value of the current sampling resistor R1, R2 represents the resistance value of the diagnostic resistor R2, and R4 represents the resistance value of the first detection resistor R4. When the first voltage is equal to the second preset voltage, the connecting cable is in a short-circuit state, short-circuiting the first detection resistor R4. At this time, the output signal of the detected object is consistent with the output signal of a normal normally open digital input signal, and the connecting cable is in a safe failure state. When the power supply is 24V, the second preset voltage is... In this formula, R1 represents the resistance value of the current sampling resistor R1, and R2 represents the resistance value of the diagnostic resistor R2; when the first voltage is zero, the connection cable is faulty and in an open circuit state.

[0124] It is understood that the first preset voltage and the second preset voltage can be values ​​preset in the processing module 3 in advance, and can be adjusted according to the replacement of the current sampling resistor R1, the diagnostic resistor R2 and the first detection resistor R4. This application does not make any special restrictions on the specific values ​​and setting methods of the first preset voltage and the second preset voltage.

[0125] This embodiment is a specific implementation method for determining whether a connecting cable is in a fault state based on a first voltage. Different values ​​of the first voltage correspond to different states of the connecting cable. This method is simple, quick, and easy to implement. It can effectively determine whether the connecting cable is faulty and what fault state it is in, so as to ensure the accuracy of subsequent normal data acquisition or troubleshooting operations. This further improves the accuracy of the acquisition results of the signal acquisition device, reduces errors, and ensures the accuracy and reliability of the acquisition results.

[0126] As a preferred embodiment, determining whether the connecting cable is in a fault state based on the second voltage includes:

[0127] When the second voltage is equal to the third preset voltage, it is determined that there is no fault in the connecting cable. The third preset voltage is the product of the voltage value of the power supply and the third ratio. The third ratio is the sum of the first resistance value divided by the first resistance value, the second resistance value, and the resistance value of the second detection resistor R3.

[0128] When the second voltage is equal to the second preset voltage, it is determined that the connecting cable is faulty and in a short circuit state. The second preset voltage is the product of the voltage value of the power supply and the second ratio. The second ratio is the first resistance value divided by the sum of the first resistance value and the second resistance value.

[0129] When the second voltage is zero, it is determined that the connecting cable is faulty and in an open circuit state.

[0130] Specifically, when the second voltage equals the third preset voltage, the connecting cable is fault-free. The first preset voltage is the resistance value of the current sampling resistor R1 under normal voltage division. When the power supply is 24V, the first preset voltage is... In this formula, R1 represents the resistance value of the current sampling resistor R1, R2 represents the resistance value of the diagnostic resistor R2, and R3 represents the resistance value of the second detection resistor R3. When the second voltage is equal to the second preset voltage, the connecting cable is in a short-circuit state, and the connecting cable short-circuits the second detection resistor R3. When the power supply is 24V, the second preset voltage is... In this formula, R1 represents the resistance value of the current sampling resistor R1, and R2 represents the resistance value of the diagnostic resistor R2. When the first voltage is zero, the connecting cable is faulty and in an open circuit state. At this time, the output signal of the detected object is consistent with the output signal of the normal normally closed digital input signal, and the connecting cable is in a safe failure state.

[0131] It is understood that the third preset voltage and the second preset voltage can be values ​​preset in the processing module 3 in advance, and can be adjusted according to the replacement of the current sampling resistor R1, the diagnostic resistor R2 and the second detection resistor R3. This application does not make any special restrictions on the specific values ​​and setting methods of the third preset voltage and the second preset voltage.

[0132] This embodiment is a specific implementation method for determining whether a connecting cable is in a fault state based on a second voltage. Different values ​​of the second voltage correspond to different states of the connecting cable. This method is simple, quick, and easy to implement. It can effectively determine whether the connecting cable is faulty and what fault state it is in, so as to ensure the accuracy of subsequent normal data acquisition or troubleshooting operations. This further improves the accuracy of the acquisition results of the signal acquisition device, reduces errors, and ensures the accuracy and reliability of the acquisition results.

[0133] In one preferred embodiment, the first selection module 2 includes:

[0134] The circuit consists of a first switch, an attenuator 4, a second switch, and a fixed resistor. The first switch and attenuator 4 are connected in series, and the second switch and fixed resistor are connected in series. The circuit after the first switch and attenuator 4 are connected in parallel with the circuit after the second switch and fixed resistor are connected in series. The first end of the parallel circuit is connected to the first end of the current sampling resistor R1, and the second end is connected to the analog terminal of the first analog-to-digital converter 1.

[0135] The first switch is closed when the output signal of the detected object is a digital input signal, so that the attenuator 4 attenuates the digital input signal and transmits the attenuated signal to the first analog-to-digital converter 1.

[0136] The second switch is closed when the received output signal of the detected object is an analog input signal, so that the analog input signal is transmitted to the first analog-to-digital converter 1.

[0137] Considering that the first selection module 2 will adopt different working modes when the input signal is different, a first switch connected in series with the attenuator 4 and a second switch connected in series with the fixed resistor are set. When the output signal of the detected object is a digital input signal, the first switch is closed, and the attenuator 4 is used to attenuate the digital input signal; when the output signal of the detected object is an analog input signal, the second switch is closed.

[0138] This application does not impose any particular limitations on the specific types and implementation methods of the first switch, the second switch, the attenuator 4, and the fixed resistor, etc., which can be adjusted according to the actual application environment and actual needs. It is understood that there are multiple options for the implementation of the first selection module 2. This embodiment is only one specific implementation method. Other structures of the first selection module 2 can also be used. This application does not impose any particular limitations here. The first switch and the second switch are not shown in the accompanying drawings.

[0139] like Figure 4 As shown, attenuator 4 and fixed resistor can be connected in parallel, but they are not connected to the signal acquisition device. When the output signal of the detected object is a digital input signal, attenuator 4 is soldered to the circuit of the signal acquisition device. When the output signal of the detected object is an analog input signal, it is closed, and fixed resistor is soldered to the circuit of the signal acquisition device.

[0140] Correspondingly, the specific setting method and implementation of the second selection module are similar to those of the first selection module 2. Please refer to the above description of the first selection module 2. This application will not elaborate further here.

[0141] It should also be noted that, in this specification, 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 apparatus 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 apparatus. 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 apparatus that includes said element.

[0142] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A signal acquisition device, characterized by, The signal acquisition device is connected to the object being detected via a connecting cable, and includes: The first analog-to-digital converter has its analog input terminal connected to the second terminal of the first selection module and its digital input terminal connected to the processing module. The first selection module has its first terminal connected to the first terminal of the current sampling resistor. When the received output signal of the detected object is a digital input signal, it attenuates the digital input signal and transmits the attenuated signal to the first analog-to-digital converter. When the received output signal of the detected object is an analog input signal, it transmits the analog input signal to the first analog-to-digital converter. The second terminal of the current sampling resistor is grounded. The processing module is used to receive the output signal of the first analog-to-digital converter; The first selection module includes: A first switch, an attenuator, a second switch, and a fixed resistor are connected in series. The first switch and the attenuator are connected in series, and the second switch and the fixed resistor are connected in parallel. The first terminal of the parallel circuit is connected to the first terminal of the current sampling resistor, and the second terminal is connected to the analog terminal of the first analog-to-digital converter. The first switch is used to close when the output signal of the detected object is a digital input signal, so that the attenuator attenuates the digital input signal and transmits the attenuated signal to the first analog-to-digital converter. The second switch is used to close when the received output signal of the detected object is an analog input signal, so that the analog input signal is transmitted to the first analog-to-digital converter.

2. The signal acquisition apparatus of claim 1, wherein Also includes: The second analog-to-digital converter has its analog input terminal connected to the second terminal of the second selection module, and its digital input terminal connected to the processing module. The diagnostic resistor has its first end connected to the second end of the current sampling resistor and the first end of the second selection module, respectively, and its second end is grounded. The second selection module is used to attenuate the signal at the second end of the current sampling resistor when the output signal of the received detection object is a digital input signal, and transmit the attenuated signal to the second analog-to-digital converter. When the output signal of the detected object is an analog input signal, the signal at the second end of the current sampling resistor is transmitted to the first analog-to-digital converter.

3. The signal acquisition device as described in claim 2, characterized in that, The processing module is also used for: Detect the first voltage across the current sampling resistor and the second voltage across the diagnostic resistor; Determine whether the ratio of the first voltage to the second voltage is equal to the ratio of the first resistance value of the current sampling resistor to the second resistance value of the diagnostic resistor; If so, then it is determined that the current sampling resistor is not faulty.

4. The signal acquisition device as described in claim 3, characterized in that, When the received output signal of the detected object is an analog input signal, after determining that the current sampling resistor is not faulty, the processing module is further configured to: The current value flowing through the current sampling resistor is detected; Determine whether the current value is lower than a first preset value; If the current value is lower than the first preset value, it is determined that the connecting cable is faulty and in an open circuit state. Determine whether the current value is greater than a second preset value, wherein the second preset value is greater than the first preset value; If the current value is greater than the second preset value, it is determined that the connecting cable is faulty and in a short circuit state.

5. The signal acquisition device as described in claim 3, characterized in that, When the received output signal of the detected object is a digital input signal, after determining that the current sampling resistor is not faulty, the processing module is further configured to: The voltage across the current sampling resistor is detected based on the first analog-to-digital converter and the second analog-to-digital converter; The digital input signal is determined as either normally open or normally closed based on the voltage across the current sampling resistor.

6. The signal acquisition device as described in claim 5, characterized in that, When the digital input signal is a normally open signal, the module further includes a first detection resistor connected in parallel across the detection object. The processing module is also used for: The first voltage across the current sampling resistor is detected based on the first analog-to-digital converter and the second analog-to-digital converter; The first voltage is used to determine whether the connecting cable is in a faulty state.

7. The signal acquisition device as described in claim 5, characterized in that, When the digital input signal is a normally closed signal, a second detection resistor is further included in series between the detection object and the connecting cable. The processing module is also used for: The second voltage across the current sampling resistor is detected based on the first analog-to-digital converter and the second analog-to-digital converter; The second voltage is used to determine whether the connecting cable is in a faulty state.

8. The signal acquisition device as described in claim 6, characterized in that, Determining whether the connecting cable is in a faulty state based on the first voltage includes: When the first voltage is equal to the first preset voltage, it is determined that the connecting cable is not faulty. The first preset voltage is the product of the voltage value of the power supply and the first ratio. The first ratio is the sum of the first resistance value divided by the first resistance value, the second resistance value and the resistance value of the first detection resistor. When the first voltage is equal to the second preset voltage, it is determined that the connecting cable is faulty and in a short circuit state. The second preset voltage is the product of the voltage value of the power supply and the second ratio. The second ratio is the first resistance value divided by the sum of the first resistance value and the second resistance value. When the first voltage is zero, it is determined that the connecting cable is faulty and in an open circuit state.

9. The signal acquisition device as described in claim 7, characterized in that, Determining whether the connecting cable is in a faulty state based on the second voltage includes: When the second voltage is equal to the third preset voltage, it is determined that the connecting cable is not faulty. The third preset voltage is the product of the voltage value of the power supply and the third ratio. The third ratio is the sum of the first resistance value divided by the first resistance value, the second resistance value and the resistance value of the second detection resistor. When the second voltage is equal to the second preset voltage, it is determined that the connecting cable is faulty and in a short circuit state. The second preset voltage is the product of the voltage value of the power supply and the second ratio. The second ratio is the first resistance value divided by the sum of the first resistance value and the second resistance value. When the second voltage is zero, it is determined that the connecting cable is faulty and in an open circuit state.

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