Detection circuit and detection method

Abstract

The invention discloses a detection circuit and a detection method. When the detection circuit provided by the specification is adopted to execute the detection method, the cut-off frequency of the signal of the transmitting line induced by the receiving line can be determined in a manner of enabling the structure between the controlled equipment and the control equipment to be equivalent to a high-pass filter of the high-frequency interference noise of the corresponding circuit, and then the communication frequency is set according to the cut-off frequency; and the effect of eliminating interference signals is achieved. By adopting the method, the influence of interference signals on normal transmission signals can be effectively reduced, faults such as equipment failure and out-of-control caused by the interference signals are solved, the implementation process is simple and convenient, the method can be continuously effective only by performing measurement once before formal application, and the cost is relatively low.

Description

Technical Field

[0001] This specification relates to the field of communication technologies, and particularly to a detection circuit and a detection method. Background Art

[0002] Currently, in the scenario of short-distance device wired centralized control, the most commonly used transmission technical solution is the RS-232 protocol based on voltage signals. This technology supports a wide range of devices, and the device and control solution are simple and reliable. Currently, it is the most mature technology for short-distance wired interconnection control of local devices.

[0003] In most engineering scenarios, relevant control lines are generally pre-buried during on-site implementation, and the most common pre-buried control line is a network cable. During actual use, the control end and the controlled end transmit serial control signals through the network cable. Since differential signals are transmitted inside the network cable in the form of differential twisted pairs, when transmitting the serial protocol, under the action of electromagnetic field coupling, the receiving line of the controlled device will couple the signal of its own transmitting line, generating interference current. When the control device sends a control signal to the controlled device, it will cause the receiving line of the controlled device to additionally sense interference signals, thus bringing about many faults such as device communication failure, misoperation, and inability to start.

[0004] Therefore, how to detect the generation conditions of interference signals and eliminate the interference signals generated during transmission is an urgent problem to be solved. Summary of the Invention

[0005] This specification provides a detection circuit and a detection method, as well as an improvement solution for the problems existing in the above-mentioned prior art.

[0006] This specification adopts the following technical solutions:

[0007] This specification provides a detection circuit for a centralized control system. The centralized control system includes a controlled device and a control device, and the controlled device and the control device are connected through a transmission line. The detection circuit includes:

[0008] A transmitting branch, one end of the transmitting branch is connected to the transmitting end of the controlled device, and the other end is connected to the transmitting line of the transmission line;

[0009] A receiving branch, including a switching switch. The first end of the switching switch is connected to the receiving line of the transmission line, the second end is connected to the receiving end of the controlled device through a first branch, and the third end is connected to a processing unit through a second branch. Among them, the first end of the switching switch is controllably switched and connected to the second end and the third end;

[0010] The processing unit is configured to determine a target signal strength of the interference signal based on the interference signal received by the second branch, and determine a cut-off frequency of the transmission line based on the target signal strength, where the interference signal is generated by the receiving line sensing a test signal transmitted by the controlled device through the transmitting line.

[0011] Optionally, the detection circuit is disposed in the controlled device, and the processing unit includes a processor of the controlled device;

[0012] One end of the transmitting branch is connected to a transmitting pin of the processor of the controlled device, and the other end is connected to the transmitting line;

[0013] The second end of the switching switch is connected to a receiving pin of the processor of the controlled device through the first branch, and the third end of the switching switch is connected to a serial data pin of the processor of the controlled device through the second branch.

[0014] Optionally, the detection circuit is disposed in a detection device, and the processing unit includes a processor of the detection device; the detection circuit further includes a communication line for connecting the detection device with the control device and the controlled device;

[0015] The processor of the detection device is configured to send the cut-off frequency to the control device and / or the controlled device through the communication line.

[0016] Optionally, the transmitting branch and the receiving branch are disposed in the detection device, the processing unit is disposed in a processing device, the detection device is connected to the processing device through a first communication line, and the processing device is connected to the control device and the controlled device through a second communication line;

[0017] Wherein, the processing unit is configured to send the cut-off frequency to the control device and / or the controlled device through the second communication line.

[0018] Optionally, a current-voltage conversion circuit and an analog-to-digital conversion circuit are provided on the second branch;

[0019] And / or,

[0020] The transmission line is a twisted pair, and the transmission line includes the transmitting line, the receiving line and a ground wire, and any two of the transmitting line, the receiving line and the ground wire are twisted together.

[0021] This specification provides a detection method, which is used for a centralized control system. The centralized control system includes a controlled device and a control device, and the controlled device and the control device are connected through a transmission line. The method includes:

[0022] During the process that the controlled device sends a test signal through the transmitting line of the transmission line, obtain the interference signal generated on the receiving line of the transmission line, and determine the target signal strength of the interference signal;

[0023] According to the target signal strength, determine the target capacitance value between the receiving line and the transmitting line of the transmission line;

[0024] According to the target capacitance value and the equivalent resistance of the control device determined in advance, determine the cut-off frequency between the transmitting line and the receiving line.

[0025] Optionally, the test signal includes multiple test signals repeatedly sent by the controlled device under a preset voltage; the obtaining the interference signal generated on the receiving line of the transmission line and determining the target signal strength of the interference signal includes:

[0026] Detect the signal strength of the interference signal generated on the receiving line each time the controlled device sends the test signal;

[0027] Determine the average value of the signal strength of the interference signal generated on the receiving line each time the test signal is sent as the target signal strength of the interference signal.

[0028] Optionally, the test signal includes a test signal sent by the controlled device under a preset voltage, and the determining the target capacitance value between the receiving line and the transmitting line of the transmission line according to the target signal strength of the interference signal includes:

[0029] Obtain the transmission duration of the test signal when the controlled device transmits the test signal through the transmitting line;

[0030] According to the transmission duration and the target signal strength, determine the charge amount of the test signal;

[0031] According to the charge amount and the preset voltage, determine the target capacitance value between the receiving line and the transmitting line of the transmission line.

[0032] Optionally, the test signal includes multiple test signals with different baud rates sequentially sent by the controlled device under a preset voltage; the determining the target capacitance value between the receiving line and the transmitting line of the transmission line according to the target signal strength of the interference signal includes:

[0033] For each test signal with a baud rate, detect the target signal strength of the interference signal generated on the receiving line when the controlled device sends the test signal with this baud rate;

[0034] Determine the capacitance value corresponding to the test signal of this baud rate according to the target signal strength of the interference signal and the preset voltage;

[0035] Determine the average value of the capacitance values corresponding to the test signals of each baud rate as the target capacitance value between the receiving line and the transmitting line.

[0036] Optionally, the method further includes:

[0037] Send the cut-off frequency to the controlled device and / or the control device.

[0038] This specification provides a signal transmission method, which is used for a centralized control system. The centralized control system includes a controlled device and a control device, and the controlled device and the control device are connected through a transmission line. The method includes:

[0039] Obtain a pre-determined cut-off frequency, and configure the signal frequency between the controlled device and the control device based on the cut-off frequency, where the signal frequency is not greater than the cut-off frequency, and the cut-off frequency is obtained by the detection method according to any one of claims 6 to 10.

[0040] This specification provides a computer-readable storage medium, which stores a computer program. When the computer program is executed by a processor, the above interference signal elimination method is implemented.

[0041] This specification provides a centralized control system, including:

[0042] A controlled device and a control device, where the controlled device and the control device are connected through a transmission line;

[0043] The detection circuit according to any one of claims 1 to 5.

[0044] This specification provides a readable storage medium, which stores a computer program. When the computer program is executed by a processor, the above detection and / or signal transmission method is implemented.

[0045] This specification provides an electronic device, including a memory, a processor, and a computer program stored on the memory and executable on the processor. When the processor executes the program, the above detection and / or signal transmission method is implemented.

[0046] At least one of the above technical solutions adopted by this specification can achieve the following beneficial effects:

[0047] In the detection circuit provided in this specification, it includes a transmission branch, one end of the transmission branch is connected to the transmission end of the controlled device, and the other end is connected to the transmission line of the transmission line; a receiving branch, including a switching switch, the first end of the switching switch is connected to the receiving line of the transmission line, the second end is connected to the receiving end of the controlled device through a first branch, and the third end is connected to the processing unit through a second branch, wherein the first end of the switching switch is controllably switched and connected to the second end and the third end; the processing unit is configured to determine the target signal strength of the interference signal according to the interference signal received by the second branch, and determine the cut-off frequency of the transmission line based on the target signal strength, wherein the interference signal is generated by the receiving line sensing the test signal sent by the controlled device through the transmission line.

[0048] When implementing the detection method using the detection circuit provided in this specification, the cut-off frequency of the receiving line sensing the transmission line signal can be determined by equivalently regarding the structure between the controlled device and the control device as a high-pass filter, and then the communication frequency can be set according to the cut-off frequency to achieve the effect of eliminating the interference signal. Using this method can effectively reduce the influence of the interference signal on the normally transmitted signal, solve the problems such as equipment malfunction and out-of-control caused by the interference signal, and the implementation process is simple and convenient. It only needs to be measured once before being officially put into use and can be continuously effective, with a relatively low cost. Description of the Drawings

[0049] The drawings described herein are used to provide a further understanding of this specification and constitute a part of this specification. The schematic embodiments of this specification and their descriptions are used to explain this specification and do not constitute an improper limitation of this specification. In the drawings:

[0050] Figure 1 It is a schematic diagram of the connection relationship between a control device and a controlled device provided in this specification;

[0051] Figure 2 It is a schematic diagram of the coupling mode of three lines between a control device and a controlled device provided in this specification;

[0052] Figure 3 It is a schematic diagram of the structure of a detection circuit provided in this specification arranged inside the controlled device;

[0053] Figure 4 It is a schematic diagram of the structure of an external detection device and a processing device with a detection circuit provided in this specification;

[0054] Figure 5 It is a schematic diagram of the internal structure of a detection device provided in this specification;

[0055] Figure 6 Schematic diagram of the structure of a detection device provided in this specification and arranged externally

[0056] Figure 7 Flow schematic diagram of a detection method provided in this specification

[0057] Figure 8 Schematic diagram of the electrical model of a transmitting line and a receiving line provided in this specification

[0058] Figure 9 Circuit schematic diagram of a high-pass filter provided in this specification

[0059] Figure 10 Schematic diagram of the signal test result of a detection method not executed provided in this specification

[0060] Figure 11 Schematic diagram of the signal test result after executing a detection method provided in this specification

[0061] Figure 12 Corresponding to what is provided in this specification Figure 1 Schematic diagram of the electronic device Specific implementation manners

[0062] Under a centralized control system, there are usually a control device for sending control instructions and a controlled device for receiving and executing control instructions Figure 1 Shows the connection relationship between the control device and the controlled device in a short-distance device centralized control scenario. As Figure 1 shown, the control device and the controlled device are usually connected by mutual transmitting lines, receiving lines and a common ground wire. Among them, Tx (Transmit) represents the transmitting end, Rx (Receive) represents the receiving end, and GND (Ground) represents the ground wire; the line pointing from the Tx of the controlled device to the Rx of the control device means that this line is the transmitting line for the controlled device and the receiving line for the control device; similarly, the line pointing from the Tx of the control device to the Rx of the controlled device means that this line is the transmitting line for the control device and the receiving line for the controlled device

[0063] It should be noted that although the three lines between the control device and the controlled device in Figure 1 are separated from each other and work separately, in the actual engineering application scenario, the three lines will exist in the form of differential twisted pairs and appear as a single network cable on the outside Figure 2 Shows two possible coupling methods of the three lines between the control device and the controlled device. As Figure 2As shown in the figure, a common coupling method is that the mutual emission line and the reception line are coupled together, and the ground wire is a separate line; another common coupling method is that the emission line and the reception line are respectively coupled to a ground wire.

[0064] Regardless of which coupling method is used, coupling current due to electromagnetic field effects will be generated, that is, the situation of interference current. Taking the controlled device as the main body, when the emission line returns a signal to the control device, an induced current will be generated in the reception line. Therefore, the reception line will couple the signal emitted by the emission line to generate interference. Thus, various faults such as malfunction and misoperation will occur in the controlled device due to receiving additional interference signals.

[0065] In the early stage of this application, through research on the above phenomena, it was found that in most scenarios, when the signal frequency transmitted on the emission line is relatively high, it is easier to generate interference signals on the reception line. Based on the above idea, this specification provides a detection circuit and a corresponding detection method for detecting the generation frequency of interference signals to solve the problem of interference signals generated on the reception line.

[0066] To make the purpose, technical solutions, and advantages of this specification clearer, the technical solutions of this specification will be clearly and completely described below in conjunction with specific embodiments of this specification and the corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of this specification, rather than all the embodiments. Based on the embodiments in this specification, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope protected by this application.

[0067] The following will detail the technical solutions provided by each embodiment of this specification in conjunction with the drawings.

[0068] Figure 3 A detection circuit provided for this specification, the detection circuit is applied to a centralized control system, the centralized control system includes a controlled device and a control device, the controlled device and the control device are connected through a transmission line, and the detection circuit includes:

[0069] An emission branch, one end of the emission branch is connected to the emission end of the controlled device, and the other end is connected to the emission line of the transmission line;

[0070] A reception branch, including a switching switch, the first end of the switching switch is connected to the reception line of the transmission line, the second end is connected to the reception end of the controlled device through a first branch, and the third end is connected to a processing unit through a second branch, wherein the first end of the switching switch is controllably switched and connected to the second end and the third end;

[0071] The processing unit is configured to determine a target signal strength of the interference signal according to the interference signal received by the second branch, and determine a cut-off frequency of the transmission line based on the target signal strength, where the interference signal is generated by the receiving line sensing a test signal transmitted by the controlled device through the transmitting line.

[0072] The detection circuit provided in this specification can be applied to a Figure 1 centralized control system as shown, including a control device, a controlled device, and a transmission line connecting the two. The structure of the detection circuit is as Figure 3 shown, including a transmitting branch, a receiving branch, and a processing unit.

[0073] First of all, it should be noted that for the convenience of explanation, all the transmitting lines and receiving lines involved in this specification are described with the controlled device as the main body. That is, without any other explanation, all the transmitting lines mentioned in this specification are the transmitting lines of the controlled device, and all the receiving lines are the receiving lines of the controlled device.

[0074] The transmitting branch in the detection circuit is connected between the transmitting end of the controlled device and the transmitting line of the transmission line, and is used to transmit a test signal outward. The receiving branch is used to obtain the interference signal generated on the receiving line. It has a first branch and a second branch controlled by a switching switch, and is used to connect the other end to different positions as the switching switch changes while keeping one end of the receiving branch connected to the receiving line of the transmission line unchanged. Among them, the first branch is connected to the receiving end of the controlled device, and the second branch is connected to the processing unit. The main function of the above switching switch is that when the switching switch controls the line to be connected to the first branch, the controlled device is in a normal working state at this time, and the centralized control system can work normally; when the switching switch controls the line to be connected to the second branch, the controlled device is in a debugging state at this time, and can be used to execute the detection method provided in this specification.

[0075] The processing unit obtains the interference signal through the receiving branch, analyzes the interference signal, and determines the target signal strength of the interference signal. Subsequently, the cut-off frequency of the transmission line is further determined based on the target signal strength.

[0076] The detection circuit provided in this specification can be implemented in a variety of different forms, and this specification provides several specific embodiments for reference here.

[0077] Figure 3 This is a schematic diagram of the structure of a detection circuit provided in this specification arranged inside a controlled device. Specifically, as Figure 3As shown, the detection circuit is disposed in the controlled device, and the processing unit includes the processor of the controlled device; one end of the transmitting branch is connected to the transmitting pin of the processor of the controlled device, and the other end is connected to the transmitting line; the second end of the switching switch is connected to the receiving pin of the processor of the controlled device through the first branch, and the third end of the switching switch is connected to the serial data pin of the processor of the controlled device through the second branch.

[0078] When the detection circuit is disposed inside the controlled device, the processing unit of the detection circuit can directly be the on-chip system (System on Chip, SoC) processor built in the controlled device itself. In this case, the transmitting pin of the SoC processor can be used as the transmitting end of the controlled device, and the receiving pin can be used as the receiving end of the controlled device. At the same time, a serial data pin is additionally configured on the SoC processor and is connected to the detection circuit through the second branch. Among them, the I / V conversion on the second branch represents current / voltage conversion, and the A / D acquisition represents digital / analog acquisition. By means of I / V conversion and A / D acquisition, the interference signals sensed by the receiving line can be converted into various different forms of data, which is convenient for subsequent use and expansion. The interference signals are transmitted to the SoC processor through the I2C (Inter-Integrated Circuit) protocol and are transmitted through the serial clock line SCL and the serial data line SDA. The SoC processor records the target signal strength of the interference signals sensed by the receiving line. When detection is not required and the controlled device returns to normal operation, the GPIO control switch Mux is connected to the Rx end of the SoC, that is, the receiving pin.

[0079] Figure 4 This is a schematic structural diagram of a detection device and a processing device provided in this specification, in which the detection circuit is disposed externally. Specifically, as Figure 4 shown, the transmitting branch and the receiving branch are disposed in the detection device, the processing unit is disposed in the processing device, the detection device is connected to the processing device through the first communication line, and the processing device is connected to the control device and the controlled device through the second communication line; wherein, the processing unit is configured to send the cut-off frequency to the control device and / or the controlled device through the second communication line.

[0080] In the case of Figure 4In the illustrated embodiment, the control device and the controlled device can remain unchanged. A detection device and a processing device corresponding to the detection device are connected in series on one side of the circuit of the controlled device. The function of the detection device is to measure various data, and the function of the processing device is to perform data calculation and communicate and transfer data with the control device and the controlled device. To maintain the overall system working state, a detection device is connected in series on one side of the circuit of the controlled device. At the same time, the detection device is connected to the processing device through a first communication line, and the processing device is connected to the control device and the controlled device through a second communication line. When the system is working, the processing device first sends a specific message through the second communication line to the control device to turn off the control device. Subsequently, the controlled device sends a test signal through the transmitting line. The detection device detects the interference signal coupled out by the receiving line and records and reports the baud rate of the test signal and the target signal strength information of the interference signal to the processing device. The processing device determines the cut-off frequency of the overall circuit based on the relevant data reported by the detection device and writes this information into the control device and the controlled device through the second communication line (which can be signals such as USB, serial port, SPI, etc.).

[0081] Figure 5 Schematic diagram of the internal structure of a detection device provided in this specification, as Figure 5 shown. Except for the additional conventional power supply unit, display and touch unit, and the communication line with the processing device end, the remaining structure is the same as that of the controlled device containing a detection circuit provided in this specification as Figure 3 shown, and the working principle is also the same. This specification will not elaborate further here. It should be noted that the processor used inside the controlled device is a SoC processor, while the processor required in the handheld internal device is a single-chip microcomputer, that is, a microcontroller (Microcontroller Unit, MCU) processor.

[0082] Additionally, in the above embodiment, the processing device can be further integrated into the detection device to form a system structure as Figure 6 shown. Figure 6 Schematic diagram of the structure of a detection device with a detection circuit arranged externally provided in this specification. Specifically, as Figure 6 shown, the transmitting branch and the receiving branch are arranged in the detection device, the processing unit is arranged in the processing device, the detection device is connected to the processing device through a first communication line, and the processing device is connected to the control device and the controlled device through a second communication line; wherein, the processing unit is configured to send the cut-off frequency to the control device and / or the controlled device through the second communication line. Compared with Figure 4 the structure shown, in Figure 6Integrating the functions of the processing device into the detection device can also achieve the purpose of eliminating interference signals. The detection device can additionally implement functions such as signal monitoring, signal translation / rewriting, signal connection / truncation, signal encryption, and signal enhancement.

[0083] The above-mentioned several embodiments have their own advantages and disadvantages in practical applications and can be selected according to specific requirements. For example, setting the detection circuit inside the controlled device can make the detection process more convenient and fast, but it needs to be integrated in advance during production, and the transformation cost for the controlled device that has already been produced is relatively high and difficult to implement. While setting the detection circuit in the detection device outside the controlled device can be more flexibly applied to the scenario. When including a processing device, the processing device can directly adopt various existing devices with data processing capabilities, thereby further reducing costs, but more devices will also make the execution process of the detection method more cumbersome.

[0084] Figure 7 The flow diagram of a detection method in this specification. This method is applied to a centralized control system, which includes a controlled device and a control device. The controlled device and the control device are connected through a transmission line. The method includes:

[0085] S100: During the process that the controlled device sends a test signal through the transmitting line of the transmission line, obtain the interference signal generated on the receiving line of the transmission line, and determine the target signal intensity of the interference signal.

[0086] This method is mainly applied to eliminate the interference signals received by the controlled device in the centralized control system of short-distance devices. As Figure 1 shown, in the device centralized control system involved in this specification, there are at least a control device and a controlled device. This specification mainly takes the controlled device as the main body for description. That is, all the transmitting lines and receiving lines that appear in this method belong to the controlled device without separate description and limitation.

[0087] When executing this method, the detection circuit provided in this specification is included in the centralized control system. At the same time, when executing this method, the control device is in a non-operating state throughout, that is, it is not powered on and will not generate or receive any signals.

[0088] In this step, the transmitting end of the controlled device can first send a test signal outward through the transmitting line, and the test signal will be transmitted to the control device via the transmitting line (but will not be received by the non-powered-on control device). Usually, the baud rate of the signal sent outward by the controlled device is adjustable, and the voltage is a preset voltage related to the device itself. Both can be selected according to requirements, and this specification does not make specific restrictions on this.

[0089] As introduced at the beginning of the specific implementation part of this specification, since the pre-buried wire used in the current short-distance device centralized control technology is a network cable, and the internal structure of the network cable is a differential twisted pair structure, an induced current, that is, an interference signal, will be generated between the transmitting line and the receiving line due to the electromagnetic field effect. Therefore, in this step, the target signal strength of the interference signal generated on the receiving line can be detected. Among them, the target signal strength of the interference signal is represented in the form of a current value. In other words, it is to detect the magnitude of the induced current generated on the receiving line.

[0090] Additionally, in order to ensure that the detected target signal strength is accurate enough, in this method, the accuracy of the data can be improved by repeating the test and taking the average value. Specifically, when sending a test signal, a specified number of test signals can be repeatedly sent outward through the transmitting line at a preset voltage; when detecting the target signal strength in this step, the target signal strength of the interference signal generated on the receiving line each time the controlled device sends the test signal can be detected respectively; the average value of the target signal strength of the interference signal generated on the receiving line each time the test signal is sent is determined as the target signal strength of the interference signal.

[0091] When sending a receiving signal outward through the transmitting line, the same test signal can be repeatedly sent multiple times, and the duration of each test signal is the same. At the same time, the receiving line end can execute the method in step S102 for each test signal, detect and record the signal strength, that is, the current value, of the interference signal caused by each test signal. Subsequently, by taking the average value of each signal strength, the magnitude of the target signal strength of the interference signal caused by this test signal can be obtained.

[0092] S102: Determine the target capacitance value between the receiving line and the transmitting line of the transmission line according to the target signal strength.

[0093] In this step, the target capacitance value between the transmitting line and the receiving line of the controlled device can be determined according to the preset voltage known in advance and the target signal strength of the interference signal measured in step S100. Those skilled in the art understand that since there is a coupling relationship between the transmitting line and the receiving line, there will correspondingly be a coupling capacitance between these two lines. The purpose of this step is to determine the magnitude of this coupling capacitance.

[0094] The voltage value of the induced current caused by the test signal is the same as the voltage value of the test signal itself, which is the preset voltage. When the voltage and current magnitudes of the known interference signal are known, and the duration of the test signal can be obtained according to the initial settings, the capacitance value between the transmitting line and the receiving line can be determined by calculating the electric charge. Specifically, the transmission duration of the test signal transmitted by the controlled device through the transmitting line can be obtained; according to the transmission duration and the target signal strength, the electric charge of the test signal can be determined; according to the electric charge and the preset voltage, the target capacitance value between the receiving line and the transmitting line of the transmission line can be determined. The above method can be expressed by the following formula:

[0095]

[0096] In the above formula, Q represents the electric charge of the interference signal, C represents the target capacitance value to be finally obtained, U represents the preset voltage, i represents the target signal strength, and t represents the duration of the test signal. When U, i, and t are all known, the magnitude of the target capacitance value C can be calculated accordingly.

[0097] Additionally, to ensure that the calculated target capacitance value is reliable enough, the capacitance value under multiple different test signals can be tested by controlling variables. Specifically, when sending the test signal in step S100, the test signal can be sent outward at different baud rates under the preset voltage; correspondingly, when determining the target capacitance value, for the test signal of each baud rate, the target signal strength of the interference signal generated on the receiving line when the controlled device sends the test signal of this baud rate can be detected; according to the target signal strength of the interference signal and the preset voltage, the capacitance value corresponding to the test signal of this baud rate can be determined; the average value of the capacitance values corresponding to the test signals of each baud rate is determined as the target capacitance value between the receiving line and the transmitting line.

[0098] When sending a test signal through the transmission line in step S100, multiple different test signals can be sent by changing the baud rate of the test signal. The number of times of sending the test signal and the baud rate of each test signal can be set according to specific requirements, and this specification does not make specific restrictions on this. For example, the baud rate of the test signal can be 2400bps, 4800bps, 9600bps, 19200bps, 38400bps, 57600bps, 115200bps, etc. The preset voltage and duration of each test signal should be kept the same. When obtaining the interference signal, the target signal intensity of the interference signal caused by each test signal with a certain baud rate can be correspondingly measured separately. Based on this, in this step, the capacitance value between the transmission line and the receiving line at each baud rate can be calculated according to the target signal intensity of the interference signal caused by the test signal with each baud rate, as well as the preset voltage and duration of the test signal. Ideally, the capacitance values at different baud rates should be the same. Finally, the average of each capacitance value can be taken to determine the effective target capacitance value between the transmission line and the receiving line.

[0099] S104: Determine the cut-off frequency between the transmission line and the receiving line according to the target capacitance value and the equivalent resistance of the control device determined in advance.

[0100] In this step, the cut-off frequency between the transmission line and the receiving line can be determined according to the target capacitance value between the transmission line and the receiving line determined in step S102, and the equivalent resistance of the control device determined in advance. Among them, to determine the equivalent resistance of the control device in advance, specifically, the resistance value inside the control device in the non-working state can be determined as the equivalent resistance of the control device. There are various ways to test the equivalent resistance of the control device. For example, a voltage can be applied to both ends of the non-working control device to measure the current magnitude, or a resistance tester and other tools can be directly used for testing. This specification does not make specific restrictions on this.

[0101] Figure 8 It is a schematic diagram of the electrical model of the transmission line and the receiving line provided by this specification. This specification gives Figure 2 two possible coupling methods between the receiving line and the transmission line in the network cable. No matter which one of these two coupling methods is, it can be equivalent to the electrical model as Figure 8 shown. As Figure 8 shown, there are coupling capacitors between the transmission line and the receiving line, between the transmission line and the ground wire, and between the receiving line and the ground wire of the controlled device. Among them, the coupling capacitors between the transmission line / receiving line and the ground wire do not affect the content concerned by this method. The main coupling capacitor to be calculated is the coupling capacitor between the transmission line and the receiving line.

[0102] Furthermore, since the control device is in a non-operating state, it can be regarded as a high-impedance state, and its resistance value is the equivalent resistance of the control device. On this basis, Figure 8 the electrical model shown can be further regarded as a high-pass filter model. Figure 9 This is a circuit schematic diagram of a high-pass filter provided in this specification. As Figure 9 shown, in addition to the coupling capacitor C existing between the transmitting line and the receiving line, there is also a resistor R grounded at one end, which is the equivalent resistance of the control device, and this form of circuit structure is actually the structure of a high-pass filter.

[0103] Therefore, the cut-off frequency between the transmitting line and the receiving line can be determined by using the calculation formula of the cut-off frequency of the high-pass filter. Specifically, the target capacitance value and the equivalent resistance of the control device determined in advance can be used as the capacitance and resistance in the high-pass filter respectively to determine the cut-off frequency of the high-pass filter as the cut-off frequency between the transmitting line and the receiving line. The specific formula is as follows:

[0104]

[0105] where F is the cut-off frequency to be calculated, R is the equivalent resistance of the control device, and C is the target capacitance value between the transmitting line and the receiving line. Thus, the cut-off frequency between the transmitting line and the receiving line can be determined.

[0106] After determining the cut-off frequency, additionally, the cut-off frequency can be sent to the controlled device and / or the control device. In this way, the frequency of the signal transmitted between the control device and the controlled device can be set according to the determined cut-off frequency so that the transmitted signal does not generate an induced current.

[0107] Since the working principle of the high-pass filter is to filter out all signals with frequencies below the cut-off frequency, it can be considered that only when the frequency of the signal transmitted by the transmitting line is greater than the cut-off frequency will an induced interference signal be generated. Based on this, the frequency of the signal transmitted between the control device and the controlled device can be set not to be greater than the cut-off frequency.

[0108] So far, as long as the signals transmitted between the control device and the controlled device during operation are not greater than the cut-off frequency, no induced current will be generated, and the purpose of eliminating interference signals is achieved.

[0109] Correspondingly, this specification also provides a signal transmission method corresponding to the detection method. This method is also applied to the centralized control system. The centralized control system includes a controlled device and a control device. The controlled device and the control device are connected through a transmission line. This method includes:

[0110] A predetermined cutoff frequency is obtained, and a signal frequency between the controlled device and the control device is configured based on the cutoff frequency, wherein the signal frequency is not greater than the cutoff frequency, and the cutoff frequency is obtained by the detection method provided in this specification.

[0111] When using the detection method provided in this specification, the cutoff frequency of the receiving line sensing the transmitting line signal can be determined by making the structure between the controlled device and the control device equivalent to a high-pass filter, and then the communication frequency can be set according to the cutoff frequency to achieve the effect of eliminating the interference signal. This method can effectively reduce the impact of interference signals on normal transmission signals, solve equipment failures, loss of control and other faults caused by interference signals, and the implementation process is simple and convenient. It only needs to be measured once before it is officially put into use to be continuously effective, and the cost is low.

[0112] Figure 10 and Figure 11 The following are schematic diagrams of the test results of the sensing signal before and after the detection method provided in this manual is used. Figure 10 and Figure 11 In the figure, the curve with a larger signal amplitude is the test signal sent by the transmitting line, and the curve with a smaller signal amplitude is the interference signal induced by the receiving line. Figure 10 and Figure 11 As shown, without using this method Figure 10 In the example, the target signal strength of the interference signal generated by the receiving line coupling is relatively large; after the frequency of the test signal is adjusted by this method, Figure 11 The target signal strength of the interference signal coupled by the receiving line shown becomes very small. It can be seen that the suppression effect of the interference signal by this method is very prominent.

[0113] This specification also provides a computer-readable storage medium, which stores a computer program, which can be used to execute the above Figure 7 Provided detection methods.

[0114] This manual also provides Figure 12 The schematic structure diagram of the electronic device shown in FIG. Figure 12 As mentioned above, at the hardware level, the electronic device includes a processor, an internal bus, a network interface, a memory, and a non-volatile memory, and may also include other hardware required for the business. The processor reads the corresponding computer program from the non-volatile memory into the memory and then runs it to achieve the above Figure 7The detection method described above. Of course, in addition to the software implementation, this specification does not exclude other implementation methods, such as logic devices or a combination of software and hardware, etc. That is to say, the execution subject of the following processing flow is not limited to each logic unit, but can also be hardware or logic devices.

[0115] The improvement of a technology can be clearly distinguished as either a hardware improvement (e.g., improvement of circuit structures such as diodes, transistors, switches, etc.) or a software improvement (improvement of method processes). However, with the development of technology, many improvements of method processes today can be regarded as direct improvements of hardware circuit structures. Almost all designers obtain the corresponding hardware circuit structures by programming the improved method processes into the hardware circuits. Therefore, it cannot be said that an improvement of a method process cannot be implemented by a hardware entity module. For example, a programmable logic device (PLD) (e.g., a field programmable gate array (FPGA)) is such an integrated circuit whose logical function is determined by the user programming the device. Designers can program by themselves to "integrate" a digital system on a piece of PLD without asking the chip manufacturer to design and fabricate a dedicated integrated circuit chip. Moreover, nowadays, instead of manually fabricating integrated circuit chips, this programming is mostly implemented using "logic compiler" software, which is similar to the software compiler used in program development and writing. The original code before compilation also has to be written in a specific programming language, which is called a hardware description language (HDL), and there is not only one kind of HDL, but many kinds, such as ABEL (Advanced Boolean Expression Language), AHDL (Altera Hardware Description Language), Confluence, CUPL (Cornell University Programming Language), HDCal, JHDL (Java Hardware Description Language), Lava, Lola, MyHDL, PALASM, RHDL (Ruby Hardware Description Language), etc. The most commonly used ones currently are VHDL (Very-High-Speed Integrated Circuit Hardware Description Language) and Verilog. Those skilled in the art should also be aware that as long as the method process is slightly logically programmed with the above-mentioned several hardware description languages and programmed into the integrated circuit, it is easy to obtain the hardware circuit that implements the logical method process.

[0116] The controller can be implemented in any suitable manner. For example, the controller can take the form of, for example, a microprocessor or a processor and a computer-readable medium storing computer-readable program code (such as software or firmware) executable by the (micro)processor, logic gates, switches, an application specific integrated circuit (ASIC), a programmable logic controller, and an embedded microcontroller. Examples of the controller include, but are not limited to, the following microcontrollers: ARC 625D, Atmel AT91SAM, Microchip PIC18F26K20, and Silicone Labs C8051F320. The memory controller can also be implemented as part of the control logic of the memory. Those skilled in the art also know that, in addition to implementing the controller in the form of pure computer-readable program code, it is entirely possible to logically program the method steps to enable the controller to be implemented in the form of logic gates, switches, application specific integrated circuits, programmable logic controllers, embedded microcontrollers, etc. to achieve the same function. Therefore, such a controller can be considered a hardware component, and the devices included therein for implementing various functions can also be regarded as the structures within the hardware component. Or even, the devices for implementing various functions can be regarded as either software modules for implementing the method or structures within the hardware component.

[0117] The systems, devices, modules, or units illustrated in the above embodiments can be specifically implemented by computer chips or entities, or by products with certain functions. A typical implementation device is a computer. Specifically, the computer can be, for example, a personal computer, a laptop computer, a cellular phone, a camera phone, a smart phone, a personal digital assistant, a media player, a navigation device, an email device, a game console, a tablet computer, a wearable device, or any combination of these devices.

[0118] For the convenience of description, when describing the above devices, they are described separately as various units according to their functions. Of course, when implementing this specification, the functions of each unit can be implemented in the same or multiple software and / or hardware.

[0119] Those skilled in the art should understand that the embodiments of the present application can be provided as a method, a system, or a computer program product. Therefore, the present application can take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present application can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk memory, CD-ROM, optical memory, etc.) containing computer-usable program code.

[0120] This application is described with reference to the flowcharts and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the application. It should be understood that each flow and / or block in the flowcharts and / or block diagrams, and combinations of flows and / or blocks in the flowcharts and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to the processors of general-purpose computers, special-purpose computers, embedded processors, or other programmable data processing devices to generate a machine, such that the instructions executed by the processors of the computer or other programmable data processing devices produce means for implementing the functions specified in one flow Figure 1 one flow or multiple flows and / or blocks Figure 1 or multiple blocks.

[0121] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to work in a specific manner, such that the instructions stored in the computer-readable memory produce a manufacture including instruction means that implement the functions specified in one flow Figure 1 one flow or multiple flows and / or blocks Figure 1 or multiple blocks.

[0122] These computer program instructions can also be loaded onto a computer or other programmable data processing device, such that a series of operational steps are executed on the computer or other programmable device to generate a computer-implemented process, and thus the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in one flow Figure 1 one flow or multiple flows and / or blocks Figure 1 or multiple blocks.

[0123] In a typical configuration, a computing device includes one or more processors (CPUs), an input / output interface, a network interface, and memory.

[0124] The memory may include non-permanent memory in the form of computer-readable media, random access memory (RAM), and / or non-volatile memory such as read-only memory (ROM) or flash RAM. The memory is an example of computer-readable media.

[0125] A computer-readable medium includes both permanent and non-permanent, removable and non-removable media and can implement information storage by any method or technology. The information can be computer-readable instructions, data structures, program modules, or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, compact disc read-only memory (CD-ROM), digital versatile disc (DVD) or other optical storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other non-transitory medium that can be used to store information accessible by a computing device. As defined herein, a computer-readable medium does not include transitory computer-readable media such as modulated data signals and carrier waves.

[0126] It should also be noted that the term "comprising", "including" or any other variation thereof is intended to cover non-exclusive inclusion, such that a process, method, commodity or device comprising a series of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, commodity or device. Without further limitation, an element defined by the statement "comprising an..." does not exclude the presence of additional identical elements in the process, method, commodity or device comprising the element.

[0127] Those skilled in the art should understand that the embodiments of this specification can be provided as a method, a system or a computer program product. Therefore, this specification can take the form of an all-hardware embodiment, an all-software embodiment, or an embodiment combining software and hardware aspects. Moreover, this specification can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0128] This specification can be described in the general context of computer-executable instructions executed by a computer, such as program modules. Generally, program modules include routines, programs, objects, components, data structures, etc. that perform specific tasks or implement specific abstract data types. This specification can also be practiced in a distributed computing environment where tasks are performed by remote processing devices connected through a communication network. In a distributed computing environment, program modules can be located in local and remote computer storage media including storage devices.

[0129] The various embodiments in this specification are described in a progressive manner. For the same or similar parts among the various embodiments, reference can be made to each other. Each embodiment focuses on the differences from other embodiments. In particular, for the system embodiments, since they are basically similar to the method embodiments, the description is relatively simple, and for the relevant parts, reference can be made to the partial description of the method embodiments.

[0130] The above description is only for the embodiments of this specification and is not intended to limit this specification. For those skilled in the art, various changes and modifications can be made to this specification. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of this specification shall be included within the scope of the claims of this application.

Claims

1. A detection circuit, characterized in that: Used in a centralized control system, the centralized control system includes a controlled device and a control device, the controlled device and the control device are connected via a transmission line, and the detection circuit includes: A transmitting branch, one end of which is connected to the transmitting end of the controlled device, and the other end of which is connected to the transmitting line of the transmission line; A receiving branch, comprising a switch, wherein a first end of the switch is connected to a receiving line of the transmission line, a second end is connected to a receiving end of the controlled device through a first branch, and a third end is connected to a processing unit through a second branch, wherein the first end of the switch is controlled to be switched and connected to the second end and the third end; The processing unit is configured to determine a target signal strength of the interference signal according to the interference signal received by the second branch, and determine a cutoff frequency of the transmission line based on the target signal strength, wherein the interference signal is generated by the receiving line induction of a test signal sent by the controlled device through the transmitting line.

2. The detection circuit according to claim 1, characterized in that: The detection circuit is provided in the controlled device, and the processing unit includes a processor of the controlled device; One end of the transmitting branch is connected to the transmitting pin of the processor of the controlled device, and the other end is connected to the transmitting line; The second end of the switch is connected to a receiving pin of a processor of the controlled device through the first branch, and the third end of the switch is connected to a serial data pin of the processor of the controlled device through the second branch.

3. The detection circuit according to claim 1, characterized in that: The detection circuit is provided in the detection device, and the processing unit includes a processor of the detection device; the detection circuit also includes a communication line, and the communication line is used to connect the detection device with the control device and the controlled device; The processor of the detection device is configured to send the cutoff frequency to the control device and / or the controlled device through the communication line.

4. The detection circuit according to claim 1, characterized in that: The transmitting branch and the receiving branch are arranged in a detection device, the processing unit is arranged in the processing device, the detection device is connected to the processing device via a first communication line, and the processing device is connected to the control device and the controlled device via a second communication line; Wherein, the processing unit is configured to send the cutoff frequency to the control device and / or the controlled device through the second communication line.

5. The detection circuit according to any one of claims 1 to 4, characterized in that: The second branch is provided with a current-voltage conversion circuit and an analog-to-digital conversion circuit; and / or, The transmission line is a twisted pair, and the transmission line includes the transmitting line, the receiving line and a ground line, and any two of the transmitting line, the receiving line and the ground line are twisted.

6. A detection method, characterized in that: Used in a centralized control system, the centralized control system includes a controlled device and a control device, the controlled device and the control device are connected via a transmission line, the method includes: In the process of the controlled device sending a test signal through the transmission line of the transmission line, obtaining an interference signal generated on the receiving line of the transmission line, and determining a target signal strength of the interference signal; Determining a target capacitance value between a receiving line and a transmitting line of the transmission line according to the target signal strength; A cutoff frequency between the transmitting circuit and the receiving circuit is determined according to the target capacitance value and a predetermined equivalent resistance of the control device.

7. The method according to claim 6, characterized in that The test signal includes a plurality of test signals repeatedly sent by the controlled device at a preset voltage; the obtaining of the interference signal generated on the receiving line of the transmission line and determining the target signal strength of the interference signal includes: Respectively detecting the signal strength of the interference signal generated on the receiving line each time the controlled device sends the test signal; The average value of the signal strength of the interference signal generated on the receiving line each time the test signal is sent is determined as the target signal strength of the interference signal.

8. The detection method according to claim 6, characterized in that: The test signal includes a test signal sent by the controlled device at a preset voltage, and determining a target capacitance value between a receiving line and a transmitting line of the transmission line according to a target signal strength of the interference signal includes: Acquire the transmission duration of the test signal transmitted by the controlled device through the transmission line; Determining the charge amount of the test signal according to the emission duration and the target signal strength; A target capacitance value between a receiving circuit and a transmitting circuit of the transmission circuit is determined according to the charge amount and the preset voltage.

9. The method according to claim 6, characterized in that The test signal includes a plurality of test signals of different baud rates sequentially sent by the controlled device under a preset voltage; The step of determining a target capacitance value between a receiving line and a transmitting line of the transmission line according to a target signal strength of the interference signal includes: For each baud rate test signal, detecting a target signal strength of an interference signal generated on the receiving line when the controlled device sends the baud rate test signal; Determining a capacitance value corresponding to the test signal of the baud rate according to the target signal strength of the interference signal and the preset voltage; An average value of the capacitance values ​​corresponding to the test signal at each baud rate is determined as a target capacitance value between the receiving circuit and the transmitting circuit.

10. The method according to claim 6, characterized in that The method further comprises: The cut-off frequency is sent to the controlled device and / or the control device.

11. A signal transmission method, characterized in that: The method is used in a centralized control system, the centralized control system includes a controlled device and a control device, the controlled device and the control device are connected via a transmission line, and the method includes: Obtain a predetermined cutoff frequency, and configure the signal frequency between the controlled device and the control device based on the cutoff frequency, wherein the signal frequency is not greater than the cutoff frequency, and the cutoff frequency is obtained by the detection method described in any one of claims 6 to 10.

12. A centralized control system, characterized in that: include: A controlled device and a controlling device, wherein the controlled device and the controlling device are connected via a transmission line; A detection circuit according to any one of claims 1 to 5.

13. A computer-readable storage medium, characterized in that: The storage medium stores a computer program, and when the computer program is executed by a processor, the method according to any one of claims 6 to 11 is implemented.

14. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the program, the method according to any one of claims 6 to 11 is implemented.

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