Self-checking circuit for switch quantity transmitting interface

Abstract

A traditional self-detecting method is to compare the output command and the output signal state to determine whether they are consistent, the method is to control the command end to the switch value sending end, the middle circuit is too much and the component failure is uncontrollable, which leads to inaccurate detection results; another method is to compare the output signal of the relay in the recovery circuit and the output signal state to determine whether they are consistent, the method uses the 28V power supply on the machine to form a loop with the relay, the recovery voltage dividing point signal determines the relay state, only considers the 28V power supply state of the aircraft power supply, and does not consider the 16V-32V interval of the corresponding equipment of the aircraft power supply, thereby leading to unreliable detection results. The present application provides a low-cost, high-accuracy and high-reliability switch value sending interface self-detecting method and circuit.

Description

Technical Field

[0001] This invention belongs to the field of electronic technology, and in particular relates to a self-test circuit for a switch signal transmission interface. Background Technology

[0002] In the field of avionics, the digital input / output interface (DIOI) is a particularly important control interface in electromechanical systems. It can directly or indirectly control onboard signal indicator lights, landing gear retraction / extension, and solenoid valve retraction / extension, among other electromechanical units. If a malfunction of the DIOI during flight causes the signal indicator lights or related electromechanical units to malfunction, and alarm prompts and remedial measures are not quickly and accurately detected, serious consequences will inevitably result. To ensure the accuracy, reliability, and detectability of the DIOI output, specific detection methods have been developed for different DIOI circuits.

[0003] Existing self-testing methods include two approaches: one compares the output command and output electrical signal states to determine consistency. This method involves a loop from the control command terminal to the switch quantity sending terminal, resulting in excessive intermediate circuitry and uncontrollable component failures. For example, temperature and environmental factors can alter component operating parameters, leading to inaccurate test results. The other approach compares the relay output electrical signal and its state within the circuit to determine consistency. This method uses the aircraft's 28V power supply to form a loop with the relay, and samples the voltage divider signal to determine the relay state. While theoretically 28V, the actual voltage fluctuates between 16-32V. This approach only considers the aircraft's 28V power supply, neglecting the 16V-32V range of the corresponding equipment's power supply, thus leading to unreliable test results.

[0004] In view of this, the present invention is hereby proposed. Summary of the Invention

[0005] The purpose of this invention is to provide a self-test circuit for a switch signal transmission interface, at least solving the technical problem of low detection efficiency in the prior art. The technical solution of this invention has many beneficial effects, as described below:

[0006] A self-test circuit for a switch signal transmitting interface is provided for performance testing of the switch signal transmitting interface. It is characterized by comprising a fluctuating power supply, a first optocoupler switch, a second optocoupler switch, and a diode connected in sequence. The output terminal of the first optocoupler switch is connected to a first detection module, the output terminal of the second optocoupler switch is connected to a second detection module, and the cathode of the diode is connected as the output terminal, serving as the output of a control signal.

[0007] The first detection module includes resistor R1, resistor R2, and a first comparator. The input terminal of resistor R1 is connected to the output terminal of the first optocoupler switch, and its output terminal is connected to the input terminal of resistor R2 and the input terminal of the first comparator, respectively. The output terminal of resistor R2 is grounded. The first comparator can acquire the voltage at the input terminal of resistor R1 and the first threshold voltage in real time, compare them, and output the result.

[0008] The second detection module includes resistors R3, R4, and R5 connected in parallel, and a second comparator. The input terminal of resistor R3 is connected to the output terminal of the second optocoupler switch, and its output terminal is connected to the input terminals of resistors R4 and R5, as well as the input terminal of the second comparator. The output terminal of resistor R5 is grounded, and the output terminal of resistor R4 is connected to a negative voltage. The second comparator can acquire the voltage at the input terminal of resistor R3 and the second threshold voltage in real time, compare them, and output the result.

[0009] Compared with the prior art, the technical solution provided by the present invention has the following beneficial effects:

[0010] The circuit provided in this case employs electronic components such as resistors and comparators to design the data acquisition circuit and threshold comparison circuit, resulting in high stability and low cost. Under the on-board power supply range of 16V to 32V, the logic values ​​of the data acquisition results corresponding to different operating states are unique, enhancing the reliability of self-testing. The data acquisition monitoring point is set at the midpoint of the interface path. By sending commands via a switch, comparing the logic values ​​of the data acquisition results with the switch command results, the accuracy of self-testing is enhanced. Attached Figure Description

[0011] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0012] Figure 1 This is a schematic diagram of state 1 of the self-test method for the switch quantity sending interface;

[0013] Figure 2 This is a schematic diagram of state 2 of the self-test method for the switch quantity sending interface;

[0014] Figure 3 This is a schematic diagram of state 3 of the self-test method for the switch quantity sending interface;

[0015] Figure 4 This is a schematic diagram of state 4 of the self-test method for the switch quantity sending interface. Detailed Implementation

[0016] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that, in the absence of conflict, the following embodiments and features in the embodiments can be combined with each other. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0017] It should be noted that various aspects of embodiments within the scope of the appended claims are described below. It will be apparent that the aspects described herein can be embodied in a wide variety of forms, and any particular structure and / or function described herein is merely illustrative. Based on this invention, those skilled in the art will understand that one aspect described herein can be implemented independently of any other aspect, and two or more of these aspects can be combined in various ways. For example, any number of aspects set forth herein can be used to implement the device and / or practice the method. Additionally, this device and / or method can be implemented using structures and / or functionalities other than one or more of the aspects set forth herein.

[0018] It should also be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. The drawings only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0019] Furthermore, specific details are provided in the following description to facilitate a thorough understanding of the examples. However, those skilled in the art will understand that aspects can be practiced without these specific details. To enable those skilled in the art to better understand the invention, the invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined as "first" and "second" may explicitly or implicitly include one or more of that feature. In the description of the invention, unless otherwise stated, "a plurality of" means two or more.

[0020] Existing methods only consider the aircraft power supply as 28V, without considering that the corresponding equipment's aircraft power supply is in the range of 16V to 32V. This leads to unreliable test results, that is, only considering the 28V power supply state and not taking into account the influence of the voltage range of 16V to 32V.

[0021] like Figure 1 The self-test circuit of the switch signal transmitting interface shown is used for performance testing of the switch signal transmitting interface, for example, for detecting voltages in the 16V to 32V range. It includes a fluctuating power supply, a first optocoupler switch, a second optocoupler switch, and a diode, which are connected in sequence. The output terminal of the first optocoupler switch is connected to a first detection module, the output terminal of the second optocoupler switch is connected to a second detection module, and the cathode of the diode is connected as the output terminal, serving as the output of a control signal.

[0022] The first detection module includes resistor R1, resistor R2, and a first comparator. The input terminal of resistor R1 is connected to the output terminal of the first optocoupler switch, and its output terminal is connected to the input terminal of resistor R2 and the input terminal of the first comparator respectively. The output terminal of resistor R2 is grounded. The first comparator can acquire the voltage at the input terminal of resistor R1 and the first threshold voltage in real time, compare them, and output the result.

[0023] The second detection module includes resistors R3, R4, and R5 connected in parallel, and a second comparator. The input terminal of resistor R3 is connected to the output terminal of the second optocoupler switch, and its output terminal is connected to the input terminals of resistors R4 and R5, as well as the input terminal of the second comparator. The output terminal of resistor R5 is grounded, and the output terminal of resistor R4 is connected to a negative voltage. The second comparator can acquire the voltage at the input terminal of resistor R3 and the second threshold voltage in real time, compare them, and output the result. Specifically, the output terminal of resistor R4 is connected to a -15V power supply to ensure that there is a potential difference in the second detection module when the first optocoupler switch is closed and the second optocoupler switch is open.

[0024] A self-test method for a switch signal transmission interface using the above-described circuit includes:

[0025] Step 1: Control the first optocoupler switch to open and the second optocoupler switch to open, and obtain the logic values ​​of the first comparator and the second comparator respectively as the first result;

[0026] Step 2: Control the first optocoupler switch to close and the second optocoupler switch to open, and obtain the logic values ​​of the first comparator and the second comparator respectively, as the second result;

[0027] Step 3: Control the first optocoupler switch to open and the second optocoupler switch to close, and obtain the logic values ​​of the first comparator and the second comparator respectively, as the third result;

[0028] Step 4: During the power-on self-test, the first, second, and third results are collected as logic standards. The collection results of the first and second optocouplers are acquired in real time within a preset time period, and it is determined whether they overlap with the logic standards. If they do, no alarm signal is fed back; otherwise, an alarm signal is fed back.

[0029] During steps 1 to 3, the switch input is kept in an open-circuit state. The method for determining the logic values ​​of the first and second comparators is as follows:

[0030] Each input voltage is compared with the input threshold voltage. If the input voltage is greater than the threshold voltage, the comparison result is output as "1"; if it is less than the threshold voltage, the comparison result is output as "0".

[0031] As a specific implementation method provided in this case, it also includes periodic self-testing. During the self-testing process, if the switch quantity transmission commands, the logic values ​​of the acquired results, and the switch quantity transmission results of each channel are consistent, it is considered correct. Specifically:

[0032] Step 1: Set the first optocoupler switch to be always closed under normal operating conditions, and the second optocoupler switch to close or open according to the control command to realize the transmission of 28V / open type switching quantity;

[0033] Step 2: Collect the voltage values ​​of the output voltage points AS of resistor R1 and BS of resistor R3. After comparing them with the first comparator and the second comparator respectively, obtain the sampling result A and the sampling result B, and simultaneously obtain the logic value. Change the thresholds of the first comparator and the second comparator, compare them again, and obtain the sampling result A and the sampling result B, and simultaneously obtain the logic value.

[0034] Step 3: In the working state, the combined logic value of the periodic acquisition results of AS and BS voltage values ​​should be 1010 or 1111. 1010 indicates that the switch quantity is not sent, and 1111 indicates that the switch quantity is sent. If it does not match the current channel switch quantity sending command or the current channel switch quantity sending result, a warning will be issued and the optocoupler switch A or B will be disconnected as needed.

[0035] The first switch and the second switch serve as optocoupler switch A and optocoupler switch B, respectively. The output value of resistor R1 serves as point AS, and the output value of resistor R3 serves as point BS. The first comparator has a threshold value of 1 as its input, and the second comparator has a threshold value of 2 as its input. The comparison result of the first comparator serves as the sampling result A, and the comparison result of the second comparator serves as the sampling result B.

[0036] Threshold 1 and threshold 2 are selected with matching comparators based on the models of optocoupler switch A and optocoupler switch B.

[0037] See Figure 1Taking the self-test method of a 28V / on-type switch transmitter interface as an example, determine the resistance values ​​of R1-R5 to meet the following requirements:

[0038] 1. When the on-board power supply is 16V-32V, the voltage at point AS can share threshold 1, resulting in the same data acquisition result A;

[0039] 2. When the on-board power supply is 16V-32V, the voltage at points BS can share threshold 2, resulting in the same data acquisition result B;

[0040] Power-on self-test: During the self-test process, switch signals must not be sent out, such as... Figure 1 , Figure 2 and Figure 3 As shown.

[0041] Step 1: Control optocoupler switch A to open and switch B to open, such as... Figure 1 The voltage values ​​at points AS and BS are acquired using the traditional method of acquiring analog voltage. After comparison with threshold 1 and threshold 2 respectively, the acquired results A and B are obtained, with logic values ​​of 1 and 0. The values ​​of threshold 1 and threshold 2 are then changed, and the comparison is repeated to obtain acquired results A and B again, with logic values ​​of 0 and 0. Throughout this process, the digital input remains in an open-circuit state.

[0042] Step 2: Control optocoupler switch A to close and switch B to open, such as... Figure 2 The voltage values ​​at points AS and BS are acquired using the traditional method of acquiring analog voltage. After comparison with threshold 1 and threshold 2 respectively, the acquired results A and B are obtained, with logic values ​​of 1 and 0 respectively. The values ​​of threshold 1 and threshold 2 are changed, and the comparison is performed again to obtain acquired results A and B, with logic values ​​of 1 and 0 respectively. During this process, the digital input is kept in an open circuit state.

[0043] Step 3: Control optocoupler switch A to open and switch B to close, such as... Figure 3 The voltage values ​​at points AS and BS are acquired using the traditional method of acquiring analog voltage. After comparison with threshold 1 and threshold 2 respectively, the acquired results A and B are obtained, with a logic value of 0, 0. The values ​​of threshold 1 and threshold 2 are changed, and the comparison is performed again to obtain acquired results A and B, with a logic value of 0, 0. During this process, the switch signal transmission remains in an open circuit state.

[0044] Step 4: During the power-on self-test, the logical combination values ​​of the AS and BS voltage values ​​collected should be 1000, 1010, and 0000 respectively. If the logical value of the collected result in a certain step is inconsistent, a warning will be issued and optocoupler switches A and B will be disconnected as needed.

[0045] Periodic self-test: During the self-test process, if the logic values ​​of the switch input commands, the acquired results, and the switch input results of each channel are consistent, it is considered correct. Figure 2 , Figure 4 As shown.

[0046] Step 1: Set optocoupler switch A to remain closed under normal operating conditions. Optocoupler switch B closes or opens according to control commands, enabling the transmission of 28V / on type switching signals;

[0047] Step 2: Collect the voltage values ​​of points AS and BS using the traditional method of collecting analog voltage. After comparing them with threshold 1 and threshold 2 respectively, obtain the sampling result A and sampling result B, and simultaneously obtain the logical value. Change the values ​​of threshold 1 and threshold 2, compare them again, and obtain sampling result A and sampling result B, and simultaneously obtain the logical value.

[0048] Step 3: In the working state, the logic combination value of the periodic acquisition results of AS and BS voltage values ​​should be 1010 or 1111. 1010 is the state of no switch quantity transmission, and 1111 is the state of switch quantity transmission. If it does not match the current channel switch quantity transmission command or the current channel switch quantity transmission result, a warning will be reported and the optocoupler switch A or B will be disconnected as needed.

[0049] The product provided by this invention has been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the embodiments above are merely for the purpose of helping to understand the core ideas of this invention. It should be noted that those skilled in the art can make various improvements and modifications to the invention without departing from the principles of the invention, and these improvements and modifications also fall within the protection scope of the invention claims.

Claims

1. A self-test circuit for a switch signal transmission interface, used for performance testing of the switch signal transmission interface, characterized in that, The system includes a fluctuating power supply, a first optocoupler switch, a second optocoupler switch, and a diode, which are connected in sequence. The output terminal of the first optocoupler switch is connected to a first detection module, and the output terminal of the second optocoupler switch is connected to a second detection module. The cathode of the diode is connected as the output terminal, serving as the output of a control signal. The first detection module includes resistor R1, resistor R2, and a first comparator. The input terminal of resistor R1 is connected to the output terminal of the first optocoupler switch, and its output terminal is connected to the input terminal of resistor R2 and the input terminal of the first comparator, respectively. The output terminal of resistor R2 is grounded. The first comparator can acquire the voltage at the input terminal of resistor R1 and the first threshold voltage in real time, compare them, and output the result. The second detection module includes resistors R3, R4, and R5 connected in parallel, and a second comparator. The input terminal of resistor R3 is connected to the output terminal of the second optocoupler switch, and its output terminal is connected to the input terminals of resistors R4 and R5, as well as the input terminal of the second comparator. The output terminal of resistor R5 is grounded, and the output terminal of resistor R4 is connected to a negative voltage. The second comparator can acquire the voltage at the input terminal of resistor R3 and the second threshold voltage in real time, compare them, and output the result.

2. The self-test circuit according to claim 1, characterized in that, The fluctuating power supply ranges from 16V to 32V.

3. The self-test circuit according to claim 1, characterized in that, The output of resistor R4 is connected to a -15V power supply to ensure that there is a potential difference in the second detection module when the first optocoupler switch is closed and the second optocoupler switch is open.

4. A self-test method for a switch input sending interface, characterized in that, Using the self-test circuit as described in any one of claims 1 to 3, the self-test method includes: Step 1: Control the first optocoupler switch to open and the second optocoupler switch to open, and obtain the logic values ​​of the first comparator and the second comparator respectively as the first result; Step 2: Control the first optocoupler switch to close and the second optocoupler switch to open, and obtain the logic values ​​of the first comparator and the second comparator respectively as the second result; Step 3: Control the first optocoupler switch to open and the second optocoupler switch to close, and obtain the logic values ​​of the first comparator and the second comparator respectively, as the third result. Step 4: During the power-on self-test, the first result, the second result, and the third result are collected as logical standards. The collection results of the first optocoupler switch and the second optocoupler switch are acquired in real time within a preset time period, and it is determined whether they overlap with the logical standards. If they do, no alarm signal is fed back; otherwise, an alarm signal is fed back.

5. The self-testing method according to claim 4, characterized in that, During steps 1 to 3, the switch input is kept in an open state.

6. The self-testing method according to claim 5, characterized in that, The method for determining the logic values ​​of the first comparator and the second comparator is as follows: Each input value is compared with the input threshold voltage. If the input voltage is greater than the threshold voltage, the comparison result is output as "1"; if it is less than the threshold voltage, the comparison result is output as "0".

7. The self-testing method according to claim 6, characterized in that, This also includes periodic self-checks. During the self-check process, if the switch input commands, the logic values ​​of the acquired results, and the switch input results for each channel are consistent, it is considered correct. Specifically: Step 1: Set the first optocoupler switch to be always closed under normal operating conditions, and the second optocoupler switch to close or open according to the control command to realize the transmission of 28V / open type switching quantity; Step 2: Collect the voltage values ​​of the output voltage points AS of resistor R1 and BS of resistor R3. After comparing them with the first comparator and the second comparator respectively, obtain the sampling result A and the sampling result B, and simultaneously obtain the logic value. Change the thresholds of the first comparator and the second comparator, compare them again, and obtain the sampling result A and the sampling result B, and simultaneously obtain the logic value. Step 3: In the working state, the combined logic value of the periodic acquisition results of AS and BS voltage values ​​should be 1010 or 1111. 1010 indicates that the switch quantity is not sent, and 1111 indicates that the switch quantity is sent. If it does not match the current channel switch quantity sending command or the current channel switch quantity sending result, a warning will be issued and the optocoupler switch A or B will be disconnected as needed.

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