Test method of discrete magnitude input and output board based on LBE bus

Abstract

The invention relates to the technical field of discrete magnitude input and output board testing, in particular to an LBE bus-based discrete magnitude input and output board testing method, which comprises the following steps of: (1) designing a special testing circuit board, and correctly mounting a discrete magnitude input and output board on the special testing circuit board; (2) connecting the industrial personal computer with the special test circuit board by using two RS-232 serial port cables, and connecting the direct-current voltage source with the special test circuit board by using a power line; and (3) selecting a corresponding test item after electrifying, and clicking to start the test to automatically finish the test. According to the invention, the automatic test of the single board is realized, the working intensity of workers is greatly reduced, and the test and maintenance capability of aviation airborne products is improved; the working state of the discrete magnitude input and output board in an original product is restored through the LBE bus analog circuit, full coverage testing of all functions and visualization of testing results are achieved, and fault channels and related devices are accurately positioned.

Description

Technical Field

[0001] The invention relates to the technical field of discrete quantity input and output board testing, in particular to a testing method of a discrete quantity input and output board based on an LBE bus. Background Art

[0002] The maintenance of aviation products usually takes the entire product as the basic unit, and it is impossible to locate the specific fault point.

[0003] When performing single-board testing on circuit boards with complex functions, a large number of devices, and a large number of chip pins, if each chip is powered on and tested individually, the steps are cumbersome and inefficient, and the circuit board may be burned due to misoperation. It is impossible to provide fast and effective technical support for scenarios such as performance testing and troubleshooting.

[0004] The internal data transmission of aviation products usually adopts a certain bus specification. The bus resources cannot be obtained when the product is not tested on a single board. Therefore, the working logic and working status on the original product cannot be restored, and effective technical support cannot be provided for fault reproduction.

[0005] In summary, the present invention takes a discrete quantity input and output board based on LBE bus as an example and designs a circuit board testing method, which can realize fast and effective detection and fault location of the circuit board. Summary of the invention

[0006] In order to solve the above technical problems, the present invention proposes a test method for discrete input and output boards based on LBE bus. Aiming at the problem of lack of relevant bus resources for single board testing and the inefficient and cumbersome status of manually applying excitation, the present method can simulate the working state and working logic of the tested circuit board in the original product under the coordinated control of the externally provided LBE bus simulator and related test resources according to the known working logic, through the relevant instructions automatically sent by the host computer, and complete the test of all the original functions of the tested circuit board, and finally make a judgment based on the test results transmitted to the host computer, which greatly saves manpower and material resources and improves the test efficiency.

[0007] The technical problem to be solved by the present invention is achieved by adopting the following technical solutions:

[0008] A method for testing a discrete quantity input and output board based on an LBE bus comprises the following steps:

[0009] Step 1: Design a special test circuit board and correctly install the discrete input and output board on the special test circuit board;

[0010] Step 2: Use two RS-232 serial cables to connect the industrial computer to the dedicated test circuit board, and use a power cord to connect the DC voltage source to the dedicated test circuit board;

[0011] Step 3: After power on, select the corresponding test item and click Start Test to automatically complete the test:

[0012] The test items include 29-channel discrete input processing circuit test, 16-channel discrete output processing circuit test with wraparound test, 20-channel discrete output processing circuit test without wraparound test and BIT self-test circuit test.

[0013] As a further improvement of the present invention, the method steps for testing the 29-channel discrete quantity input processing circuit are as follows:

[0014] Step 1: The industrial computer sends instructions to the STM32 controller to make its corresponding GPIO port output different level signals. The drive circuit controls the relay to output ground, open or 27V signals to each channel, and converts them into TTL signals through the internal comparison circuit.

[0015] Step 2: The industrial control computer sends a read instruction to the LBE bus analog control circuit. The LBE bus analog control circuit converts the instruction into a level signal that complies with the LBE bus specification and sends it to the CPLD decoding circuit in the discrete input and output board. The decoding circuit sends a chip select and read signal to read the TTL signal and upload it to the industrial control computer. It determines whether there is a fault based on the returned data.

[0016] As a further improvement of the present invention, the method steps for testing a 16-channel discrete quantity output processing circuit with a wraparound test are as follows:

[0017] Step 1: The industrial computer sends a write instruction to the LBE bus analog control circuit to control the CPLD decoding circuit in the discrete quantity input and output board to send out 36 discrete quantity output control signals, of which 16 drive the relays on the test board to make the relays output the corresponding discrete quantities to the 16 discrete signal generating circuits with wraparound test signals and convert them into TTL signals;

[0018] Step 2: The industrial computer sends a read command to the LBE bus analog control circuit to read the TTL signal and upload it to the industrial computer, and determines whether there is a fault based on the returned data.

[0019] As a further improvement of the present invention, the method steps of testing a discrete quantity output processing circuit for a 20-channel no-wrap test are as follows:

[0020] Step 1: The industrial computer sends a write instruction to the LBE bus analog control circuit to control the CPLD decoding circuit in the discrete input and output board to send 36 discrete output control signals, and the remaining 20 are used to drive the relay on the test board to make the relay output ground or 3.3V signal to the GPIO port of the STM32 controller;

[0021] Step 2: The industrial computer sends a read command to the STM32 controller to upload 20 different level signals to the industrial computer, and determines whether there is a fault based on the returned data.

[0022] As a further improvement of the present invention, the method steps of the BIT self-test circuit test are as follows:

[0023] Step 1: The different internal reference sources are connected to the 29 discrete input channels through a multiplexer;

[0024] Step 2: The industrial control computer sends a write instruction to the LBE bus analog control circuit to control the CPLD decoding circuit in the discrete input and output board to set the multiplexer so that different channels are connected to different reference sources;

[0025] Step 3: The industrial computer sends a read instruction to the LBE bus analog control circuit, which can transmit the converted TTL signal to the industrial computer and determine whether there is a fault based on the returned data.

[0026] The beneficial effects of the present invention are:

[0027] The present invention provides a testing method for a discrete quantity input and output board based on an LBE bus, which realizes the automatic testing of a single board, greatly reduces the work intensity of staff, and improves the testing and maintenance capabilities of aviation airborne products; the working state of the discrete quantity input and output board in the original product is restored through an LBE bus simulation circuit, and a full coverage test of all functions and visualization of the test results are realized, and the fault channel and related components are accurately located. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The present invention is further described below in conjunction with the accompanying drawings and embodiments:

[0029] Figure 1 The hardware block diagram of the test circuit board in the present invention;

[0030] Figure 2 This is a test flow chart of the 29-channel discrete quantity input processing circuit of the present invention;

[0031] Figure 3 This is a test flow chart of a 16-channel discrete quantity output processing circuit with wraparound test according to the present invention;

[0032] Figure 4 It is a test flow chart of a discrete quantity output processing circuit for a 20-channel no-wrap test of the present invention;

[0033] Figure 5 This is a test flow chart of the BIT self-test circuit of the present invention.

[0034] In the figure: 1. DC voltage source; 2. Industrial control computer; 3. LBE bus analog control circuit; 4. STM32 controller; 5. Power conversion circuit; 6. 29-channel discrete signal generating circuit; 7. 20-channel discrete quantity generating circuit with no wraparound test signal; 8. 16-channel discrete signal generating circuit with wraparound test signal; 9. Discrete quantity input and output board. DETAILED DESCRIPTION

[0035] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the present invention is further described below with reference to the accompanying drawings and embodiments.

[0036] The discrete quantity input and output board 9 is mainly divided into 29 discrete quantity input processing circuits, a BIT self-test circuit, 36 discrete quantity output processing circuits, 16 wrap-around test signal input processing circuits, and a CPLD decoding circuit.

[0037] A method for testing a discrete quantity input and output board based on an LBE bus comprises the following steps:

[0038] Step 1: Design a special test circuit board and correctly install the discrete input and output board 9 on the special test circuit board.

[0039] In this embodiment, a special test circuit board is designed, such as Figure 1 As shown, the test circuit board mainly includes an LBE bus analog control circuit 3, an STM32 controller 4, a power conversion circuit 5, a 29-channel discrete signal generating circuit 6, a 20-channel discrete quantity generating circuit 7 for non-wrap test signals, and a 16-channel discrete signal generating circuit 8 for wrap test signals.

[0040] The LBE bus analog control circuit 3 is connected to the industrial control computer 2 through the 232 bus and to the discrete quantity input and output board 9 through the LBE bus. The STM32 controller 4 is connected to the industrial control computer 2 through the 232 bus and to the 29-channel discrete signal generating circuit 6. The power conversion circuit 5 is connected to the DC voltage source 1 and the STM32 controller 4. The 29-channel discrete signal generating circuit 6 is connected to the discrete quantity input and output board 9. The 20-channel discrete quantity generating circuit 7 with no wraparound test signals is connected to the STM32 controller 4 and the discrete quantity input and output board 9. The 16-channel discrete signal generating circuit 8 with wraparound test signals is connected to the discrete quantity input and output board 9.

[0041] Step 2: Use two RS-232 serial cables to connect the industrial computer 2 to the dedicated test circuit board for communication between the industrial computer 2 and the STM32 controller 4 and between the industrial computer 2 and the LBE bus simulation control circuit 3; use a power cord to connect the DC voltage source 1 to the dedicated test circuit board.

[0042] Step 3: After power-on, select the corresponding test item and click Start Test to complete the test automatically.

[0043] The test content is as follows:

[0044] The test items include 29-channel discrete input processing circuit test, 16-channel discrete output processing circuit test with wraparound test, 20-channel discrete output processing circuit test without wraparound test and BIT self-test circuit test.

[0045] The test method and steps of the 29-channel discrete input processing circuit are as follows:

[0046] The industrial control computer 2 sends instructions to the STM32 controller 4 to make its corresponding GPIO port output different level signals, and the driving circuit controls the relay to output ground, open or 27V signals to each channel, and converts them into TTL signals through the internal comparison circuit; the industrial control computer 2 sends a read instruction to the LBE bus analog control circuit 3, and the LBE bus analog control circuit 3 converts the instruction into a level signal that meets the LBE bus specification and sends it to the CPLD decoding circuit. The decoding circuit sends a chip selection and a read signal to read the TTL signal and upload it to the industrial control computer 2, and determines whether it is a fault based on the returned data.

[0047] The test method and steps of 16-channel discrete output processing circuit with wraparound test are as follows:

[0048] The industrial control computer 2 sends a write instruction to the LBE bus analog control circuit 3 to control the CPLD decoding circuit to send out 36 discrete quantity output control signals, of which 16 drive the relays on the test board, so that the relays output corresponding discrete quantities to the 16 discrete signal generating circuits 8 with wraparound test signals and convert them into TTL signals; the industrial control computer 2 sends a read instruction to the LBE bus analog control circuit 3 to read the TTL signal and upload it to the industrial control computer 2, and judge whether there is a fault based on the returned data.

[0049] The test method and steps of the 20-channel discrete output processing circuit without wraparound test are as follows:

[0050] Industrial computer 2 sends a write instruction to LBE bus analog control circuit 3 to control CPLD decoding circuit to send 36 discrete output control signals, and the remaining 20 signals are used to drive the relays on the test board, so that the relays output ground or 3.3V signals to the GPIO port of STM32 controller 4; industrial computer 2 sends a read instruction to STM32 controller 4 to upload 20 different level signals to industrial computer 2, and judge whether there is a fault based on the returned data.

[0051] The test method steps of BIT self-test circuit are as follows:

[0052] Different internal reference sources are connected to 29 discrete input channels through a multiplexer; the industrial control computer 2 sends a write instruction to the LBE bus analog control circuit 3 to control the CPLD decoding circuit to set the multiplexer so that different channels can be connected to different reference sources respectively; the industrial control computer 2 sends a read instruction to the LBE bus analog control circuit 3 to transmit the converted TTL signal to the industrial control computer 2, and judge whether there is a fault based on the returned data.

[0053] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions only describe the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A method for testing a discrete quantity input and output board based on an LBE bus, characterized in that: The following steps are involved: Step (1) designing a special test circuit board, and correctly installing the discrete quantity input and output board (9) on the special test circuit board; Step (2) uses two RS-232 serial cables to connect the industrial control computer (2) to the dedicated test circuit board, and uses a power cord to connect the DC voltage source (1) to the dedicated test circuit board; Step (3) After powering on, select the corresponding test item and click Start Test to automatically complete the test: The test items include 29-channel discrete input processing circuit test, 16-channel discrete output processing circuit test with wraparound test, 20-channel discrete output processing circuit test without wraparound test and BIT self-test circuit test.

2. The method for testing a discrete quantity input and output board based on LBE bus according to claim 1, characterized in that: The special test circuit board comprises an LBE bus analog control circuit (3), an STM32 controller (4), a power conversion circuit (5), a 29-channel discrete signal generating circuit (6), a 20-channel discrete quantity generating circuit for non-wrap test signals (7), and a 16-channel discrete signal generating circuit for wrap test signals (8).

3. The method for testing a discrete quantity input and output board based on LBE bus according to claim 2, characterized in that: The LBE bus analog control circuit (3) is connected to the industrial control computer (2) through the 232 bus and is connected to the discrete quantity input and output board (9) through the LBE bus. The STM32 controller (4) is connected to the industrial control computer (2) through the 232 bus and is connected to the 29-channel discrete signal generating circuit (6). The power conversion circuit (5) is connected to the DC voltage source (1) and the STM32 controller (4). The 29-channel discrete signal generating circuit (6) is connected to the discrete quantity input and output board (9). The 20-channel discrete quantity generating circuit (7) with no wraparound test signals is connected to the STM32 controller (4) and the discrete quantity input and output board (9). The 16-channel discrete signal generating circuit (8) with wraparound test signals is connected to the discrete quantity input and output board (9).

4. The method for testing a discrete quantity input and output board based on LBE bus according to claim 1, characterized in that: The steps for testing the 29-channel discrete input processing circuit are as follows: Step 1: The industrial control computer (2) sends instructions to the STM32 controller (4) to make its corresponding GPIO port output different level signals, and the driving circuit controls the relay to output ground, open or 27V signals to each channel, and converts them into TTL signals through the internal comparison circuit; Step 2: The industrial control computer (2) sends a read instruction to the LBE bus analog control circuit (3). The LBE bus analog control circuit (3) converts the instruction into a level signal that complies with the LBE bus specification and sends it to the CPLD decoding circuit in the discrete input and output board (9). The decoding circuit sends a chip selection and a read signal to read the TTL signal and upload it to the industrial control computer (2). It determines whether there is a fault based on the returned data.

5. The method for testing a discrete quantity input and output board based on LBE bus according to claim 1, characterized in that: The method and steps for testing the 16-channel discrete output processing circuit with wraparound test are as follows: Step 1: The industrial control computer (2) sends a write instruction to the LBE bus analog control circuit (3) to control the CPLD decoding circuit in the discrete quantity input and output board (9) to send 36 discrete quantity output control signals, of which 16 drive relays on the test board to make the relays output corresponding discrete quantities to the 16 discrete signal generating circuits (8) with wraparound test signals and convert them into TTL signals; Step 2: The industrial control computer (2) sends a read instruction to the LBE bus analog control circuit (3) to read the TTL signal and upload it to the industrial control computer (2), and determine whether there is a fault based on the returned data.

6. The method for testing a discrete quantity input and output board based on LBE bus according to claim 1, characterized in that: The method and steps for testing the discrete output processing circuit of 20-channel non-wrap test are as follows: Step 1: The industrial control computer (2) sends a write instruction to the LBE bus analog control circuit (3) to control the CPLD decoding circuit in the discrete quantity input and output board (9) to send 36 discrete quantity output control signals, and the remaining 20 signals are used to drive the relay on the test board, so that the relay outputs a ground or 3.3V signal to the GPIO port of the STM32 controller (4); Step 2: The industrial control computer (2) sends a read instruction to the STM32 controller (4) to upload 20 different level signals to the industrial control computer (2), and determine whether there is a fault based on the returned data.

7. The method for testing a discrete quantity input and output board based on LBE bus according to claim 1, characterized in that: The method and steps of BIT self-test circuit test are as follows: Step 1: The different internal reference sources are connected to the 29 discrete input channels through a multiplexer; Step 2: The industrial control computer (2) sends a write instruction to the LBE bus analog control circuit (3) to control the CPLD decoding circuit in the discrete input and output board (9) to set the multiplexer so that different channels are connected to different reference sources respectively; Step 3: The industrial control computer (2) sends a read instruction to the LBE bus analog control circuit (3), so that the converted TTL signal can be transmitted to the industrial control computer (2), and whether a fault occurs can be determined based on the returned data.

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