GJB289A bus ICD missing-oriented test method

Abstract

The invention discloses a GJB289A bus ICD missing-oriented test method. The GJB289A bus ICD missing test method comprises the following steps: acquiring messages on a GJB289A bus in a normal working mode of a tested system through a first GJB289A terminal module, and forming a recording file; extracting a non-broadcast message in the recorded file, converting the extracted message into a BC instruction, and sending the BC instruction to a GJB289A bus of the tested system; obtaining the address of the remote terminal from the instruction word converted from the current instruction according to the response condition of the remote terminal to the sent instruction; obtaining a simple network message of the remote terminal; extracting an instruction from the obtained simple network message of the specified remote terminal, and judging whether the GJB289A bus communication of the tested system is normal or not; and when the GJB289A bus communication of the tested system is normal, testing the state of the specified remote terminal according to the comparison condition of the current response and the response of the pre-recorded simple network message. According to the invention, the problem that the function of the tested product cannot be tested under the condition that the ICD of the GJB289A bus is lacked is well solved.

Description

Technical Field

[0001] The invention belongs to the technical field of bus testing, and in particular relates to a GJB289 bus ICD missing testing method. Background Art

[0002] With the rapid development of electronic information systems, bus technology has been widely used. In addition to analog signals and discrete signals, a large amount of information is transmitted through bus interfaces.

[0003] In the testing field, to test such devices, it's necessary to know which bus type or types of buses the device uses, as well as the corresponding bus communication protocol, or ICD, to test the device's functional logic and performance. However, in some application scenarios, obtaining an ICD is difficult, and testing must be performed without it, making testing impossible.

[0004] The GJB289A bus is widely used in the field of avionics due to its high reliability, high real-time performance and high flexibility. However, the same problem exists in the test of the GJB289A bus in the absence of ICD. Summary of the Invention

[0005] The purpose of the present invention is to provide a GJB289 bus ICD missing test method to solve the problem that the test cannot be effectively carried out when the ICD is missing.

[0006] The present invention is achieved through the following technical solutions: The test method for GJB289A bus ICD missing includes the following steps: Step 1: Recording bus messages; including: connecting a first GJB289A terminal module to the GJB289A bus of the system under test, using the first GJB289A terminal module as the BM of the GJB289A bus of the system under test, collecting messages on the GJB289A bus of the system under test in normal working mode through the first GJB289A terminal module and forming a recording file; Step 2: Obtaining the remote terminal address of the GJB289A bus of the system under test; comprising: establishing a test network consisting of a first GJB289A terminal module as a BC and a remote terminal RT taken from the GJB289A bus of the system under test; extracting non-broadcast messages from the recorded file, converting the extracted messages into BC instructions, and sending the BC instructions to the GJB289A bus of the system under test; obtaining the address of the remote terminal based on the response of the remote terminal to the sent instruction and the instruction word converted from the current instruction; and sequentially obtaining the addresses of all remote terminals; Step 3: Obtaining simple network messages of the remote terminal; including: extracting messages related to a specified remote terminal from the recorded file, converting each of the extracted messages into instructions for BC transmission and sending them to the GJB289A bus of the system under test, recording the messages on the GJB289A bus as simple network messages of the specified remote terminal; and sequentially obtaining simple network messages of all remote terminals; Step 4, diagnostic test; including: extracting instructions from the simple network message obtained from the designated remote terminal, and sending them to the designated remote terminal through the BC, judging whether the GJB289A bus communication of the tested system is normal based on whether the designated remote terminal responds to the instructions in each simple network message; when the GJB289A bus communication of the tested system is normal, testing the status of the designated remote terminal based on the comparison between the current response and the response of the pre-recorded simple network message; completing the test of the remote terminal status of the GJB289A bus of the tested system in sequence.

[0007] In some embodiments, the non-broadcast messages extracted from the recording file in step 2 include: transmissions from the remote terminal to the BC, transmissions from the BC to the remote terminal, and mode instruction transmissions without data words.

[0008] In some embodiments, converting the extracted message into a BC instruction in step 2 includes: converting the message transmitted from the remote terminal to the BC into a sending instruction word; converting the message transmitted from the BC to the remote terminal into a receiving instruction word and a corresponding number of data words; and converting the message transmitted by the mode instruction without a data word into a mode control instruction word.

[0009] In some embodiments, in step 2, when the remote terminal responds to the sent instruction within the first preset response time, the remote terminal address in the current instruction word is used as the address of the remote terminal; When the remote terminal does not respond within the second preset response time, the remote terminal address in the current instruction word is not the address of the remote terminal, and the instruction in the next message is converted and sent to the GJB289A bus of the system under test.

[0010] In some embodiments, in step 3, the messages related to a specified remote terminal are extracted from the recording file, including: messages transmitted from the bus controller BC to the specified remote terminal RT, messages transmitted from the specified remote terminal RT to the bus controller BC, messages that are mode instructions and the remote terminal address field in the instruction is the same as the address of the specified remote terminal RT, broadcast transmissions from the bus controller BC to each remote terminal, and broadcast mode instructions.

[0011] In some embodiments, in step 3, messages related to the specified RT are extracted from the recording file and converted into BC instructions for issuance, and the conversion content includes: converting the message transmitted from BC to the specified RT into a receive instruction word with the RT address field being the specified RT address and a corresponding number of data words; converting the message transmitted from the specified RT to BC into a send instruction word with the RT address field being the specified RT address; converting the mode instruction message with the RT address being the specified RT address into a mode control instruction word, a mode instruction word or a mode instruction word and a data word; converting the message broadcasted by BC to each RT into a receive instruction word with the RT address being 11111 and a corresponding number of data words; converting the message of the broadcast mode instruction into a mode control instruction word or a mode instruction word and a data word.

[0012] In some embodiments, the remote terminal's response to the instructions in the simple network message in step 4 includes: a response to a message transmitted from the bus controller BC to the designated remote terminal RT is 1 status word; a response to a message transmitted from the designated remote terminal RT to the bus controller BC is 1 status word and a specified number of data words; a response to a message of a mode instruction and the remote terminal address field in the instruction is the same as the address of the designated remote terminal RT is 1 status word, 1 status word and 1 data word; and no response to a message of a broadcast transmission or a broadcast mode instruction from BC to each remote terminal.

[0013] In some embodiments, step 4 also includes the step of dividing simple network messages into time-independent messages and time-related messages based on the response of the remote terminal when receiving the instruction, and judging whether the status of the remote terminal is normal based on the change pattern of whether the time-independent message is responded to and the response difference to the instruction in the time-related message.

[0014] In some embodiments, for time-related message instructions, the same instruction is sent multiple times to detect the changing pattern of the response difference. When the changing pattern of the response difference is consistent with the corresponding changing pattern, the remote terminal status is judged to be normal, otherwise the remote terminal status is judged to be abnormal.

[0015] In some embodiments, the response difference variation pattern includes an increase in seconds or milliseconds, a small fluctuation, or a slow increase or small fluctuation after preheating.

[0016] Compared with the prior art, the present invention has the following advantages and beneficial effects: The present invention adopts an additional GJB289A bus to build a test network, which can realize the test of the GJB289A bus in the absence of ICD. The test system and test process are simple, which well solves the problem that the function of the tested product cannot be tested when the GJB289A bus ICD is missing. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings in the embodiments will be briefly introduced below. It should be understood that the following drawings only illustrate certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0018] Figure 1 This is a flow chart of the testing method according to an embodiment of the present invention.

[0019] Figure 2 Schematic diagram of the test network built for an embodiment of the present invention. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solutions and advantages of the present application clearer, the specific embodiments of the present application are further described in detail below in conjunction with the accompanying drawings. It is understood that the specific embodiments described herein are only used to explain the present application and are not intended to limit the present application. It should also be noted that, for ease of description, only parts related to the present application, not all of the contents, are shown in the accompanying drawings. Before discussing the exemplary embodiments in more detail, it should be mentioned that some exemplary embodiments are described as processes or methods depicted as flow charts. Although the flow charts describe each operation (or step) as a sequential process, many of the operations therein can be implemented in parallel, concurrently or simultaneously. In addition, the order of the operations can be rearranged. The process can be terminated when its operation is completed, but can also have additional steps not included in the accompanying drawings. The process can correspond to a method, function, procedure, subroutine, subprogram, etc.

[0021] The GJB289A bus network primarily consists of three parts: the bus controller (BC), the remote terminal (RT), and the bus monitor (BM). The GJB289A information flow consists of a series of GJB289A messages. A single data transmission on the bus is called a message. A message consists of a command word, a data word, and a status word. Each word consists of 20 bits, of which 3 bits are used for synchronization, 16 bits for payload, and 1 bit for parity control.

[0022] Reference Figure 1 The steps of the test method for GJB289A bus ICD missing of the present invention are as follows: Step 1. Bus Recording 1.1 Test Preparation 1) The system under test can work normally; 2) Coupler and stub for accessing the GJB289A bus of the avionics system; 3) An additional GJB289A terminal module, used as the BM and BC of the GJB289A bus during testing.

[0023] 1.2. Recording bus messages Step 2. Confirm the remote terminal address 2.1. Build a test network; 2.2. Extract non-broadcast messages from the recorded file in step 1.2; 2.3. Convert the extracted messages into BC instructions one by one and send them to the GJB289A bus; 2.4. Confirm the current remote terminal address; 2.5. Complete the confirmation of all terminal addresses.

[0024] Step 3. Get simple network messages from the remote terminal 3.1. Extract messages related to the specified remote terminal from the recorded file; 3.2. Convert the extracted messages into BC instructions one by one; 3.3. Send the converted instructions to the GJB289A bus, record the messages on the bus and save them to a file, and obtain simple network messages from a specified remote terminal; 3.4. Follow steps 3.1-3.3 to obtain simple network messages from any other remote terminal.

[0025] Step 4. Diagnostic Test 4.1, Message classification; 4.2. Diagnose remote terminal.

[0026] The testing method of the present invention is described in detail below with reference to specific examples.

[0027] In some embodiments of the present invention, the test method in the case of GJB289A bus ICD missing is as follows: Figure 1 , including the following steps: The test system includes a functioning system under test (SUT), a coupler and stub for accessing the avionics system's GJB289A bus, and another GJB289A terminal module, which serves as the bus's BM and BC during testing. To distinguish it from the avionics system's GJB289A bus, this other GJB289A terminal module is referred to as the first GJB289A terminal module.

[0028] 1. Record bus messages When recording bus messages, build a test system and refer to Figure 2The first GJB289A terminal module is connected to the GJB289A bus of the system under test through a short line and a coupler. At this time, the first GJB289A terminal module is used as the BM (bus monitor) of the GJB289A bus.

[0029] 1.1. Start BM, prepare to collect bus messages and record them in files; 1.2. Turn on the system under test and enable it to be in normal working mode, with the GJB289A bus in active state; 1.3. Collect the messages on the GJB289A bus of the system under test through BM and save them into the recording file; 1.4. After the acquisition is completed, turn off BM and the system under test.

[0030] In this step, the message collection time should be as long as possible, and the working states of the system under test should be as many as possible to ensure that various types of messages can be collected.

[0031] 2. Get the remote terminal address 2.1. Build a test network Reference Figure 2 , build a test network consisting of only two terminals, one of which is the first GJB289A terminal module of BC, and the other terminal is a remote terminal RT taken out from the GJB289A bus of the system under test.

[0032] 2.2. Extract non-broadcast messages from the recorded files, including: 1) transmission from the remote terminal to the BC; 2) transmission from the BC to the remote terminal and instruction transmission without data words.

[0033] 2.3. Convert the extracted messages into BC instructions one by one and send them to the GJB289A bus of the system under test. The instructions converted from the messages for BC sending are shown in Table 1.

[0034] Table 1 Instructions converted from messages for BC sending 2.4. Get the current remote terminal address If the remote terminal RT on the GJB289A bus can respond to the instruction issued by the BC within the first preset response time (4µs to 12µs), it can be determined that the remote terminal address in the current instruction word issued by the BC is the address of the remote terminal RT.

[0035] If the remote terminal RT does not respond within the second preset response time (greater than 14µs), the remote terminal address in the current instruction word sent by BC is not the address of the remote terminal RT, and the instruction in the next message needs to be converted and sent to the GJB289A bus.

[0036] 2.5. Get all remote terminal addresses Take out the remote terminals RT from the GJB289A bus of the system under test one by one. According to steps 2.1-2.4, the addresses of all remote terminals in the GJB289A bus of the system under test can be determined.

[0037] The GJB289A bus network is distributed. While the test equipment, acting as a BM, records information transmitted within the bus network, it doesn't know from which node the information is sent to. Therefore, it's necessary to first determine the RT address, or remote terminal address. Subsequent testing requires filtering out corresponding command-response pairs based on the RT addresses of the various devices under test.

[0038] 3. Get simple network messages from the remote terminal 3.1. Extract messages related to a specific remote terminal RT from the recording file. The extraction rules are as follows: 1) The message is transmitted from the bus controller BC to the designated remote terminal RT and needs to be extracted; 2) The message is transmitted from the remote terminal RT to the bus controller BC and needs to be extracted; 3) The message is a mode command, and the remote terminal address field in the command is the same as the specified remote terminal RT address and needs to be extracted; 4) The message is a broadcast transmission from the bus controller BC to each remote terminal and needs to be extracted; 5) The message is a broadcast command and needs to be extracted.

[0039] 3.2. Convert the extracted messages into BC instructions one by one. The converted instructions for BC sending are shown in Table 2.

[0040] Table 2: Commands sent by BC in messages related to a specified remote terminal RT 3.3. Send the converted instructions to the GJB289A bus, record the messages on the GJB289A bus and save them to a file to obtain the simple network messages of the specified remote terminal.

[0041] 3.4. Repeat steps 3.1-3.3 to obtain simple network messages of other remote terminals RT and obtain simple network messages of all remote terminals RT.

[0042] 4. Diagnostic Tests 4.1 Message Classification The messages obtained in step 3 are messages exchanged between each designated remote terminal (RT) and the BC, while other remote terminals (RTs) are blocked. Some of these messages have responses, while others do not (broadcast messages do not have responses). Some responses contain data words, while others contain only status words.

[0043] The response of the remote terminal is shown in Table 3.

[0044] Table 3 Remote terminal response status To facilitate diagnosis of remote terminal health by comparing responses, we need to first classify messages into two categories based on their characteristics: time-independent messages and time-dependent messages. These include: (1) Time-independent messages When the system under test is in normal condition, the remote terminal RT in the GJB289A bus will keep the same response whenever it receives the same instruction. Such a message is a time-independent message, and the corresponding instruction and response are time-independent message instruction and time-independent message response, respectively.

[0045] In particular, unresponsive messages are also classified as time-independent messages.

[0046] (2) Time-related messages When the system under test is in normal state, the remote terminal RT in the GJB289A bus receives the same command, but the responses it gives are different (the status words are different, or the data words are different). Such messages are time-related messages, and the corresponding commands and responses are time-related message commands and time-related message responses, respectively.

[0047] The possible reasons for the difference are that the response carries time information, digitized information of analog quantities (voltage, current, resistance, temperature, pressure, angle, etc.), etc.

[0048] When a remote terminal receives the same time-related message multiple times, its response differences often show the following changes: Table 4. Changes in response differences of time-related messages According to the characteristics of the above two messages, the message responses can be distinguished by sending the same message instruction multiple times.

[0049] 4.2. Remote terminal diagnostic test Extract the instruction from the simple network message of the designated remote terminal obtained in step 3 and send it to the designated remote terminal RT through BC.

[0050] If any instruction (non-broadcast instruction) cannot be responded, it means that the designated remote terminal RT is abnormal; if the designated remote terminal RT can respond to the instructions in each simple network message, it means that the GJB289A bus communication of the system under test is normal.

[0051] When the GJB289A bus of the system under test is diagnosed as communicating normally, it is necessary to further diagnose the status of the designated remote terminal (RT) by comparing the current response with the response in the pre-recorded simple network message. The diagnostic process is as follows: 1) If a time-independent message instruction is sent, if the current response is exactly the same as the response in the simple network message recorded in advance, it indicates that the RT status of the designated remote terminal is normal; if the current response is different from the response in the simple network message, it indicates that the RT status of the designated remote terminal is abnormal.

[0052] 2) If a time-related message instruction is sent, the same instruction needs to be sent multiple times, and the change pattern of the response difference is detected. If the change pattern of the response difference conforms to the change pattern in Table 4, the RT status of the specified remote terminal is determined to be normal. Otherwise, the RT status of the specified remote terminal is determined to be abnormal.

[0053] The test of the remote terminal of the GJB289A bus of the system under test can be completed.

[0054] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any simple modification or equivalent change made to the above embodiment based on the technical essence of the present invention shall fall within the scope of protection of the present invention.

Claims

1. A test method for GJB289A bus ICD missing, characterized in that: The following steps are involved: Step 1: Recording bus messages; including: connecting a first GJB289A terminal module to the GJB289A bus of the system under test, using the first GJB289A terminal module as the BM of the GJB289A bus of the system under test, collecting messages on the GJB289A bus of the system under test in normal working mode through the first GJB289A terminal module and forming a recording file; Step 2: Obtaining the remote terminal address of the GJB289A bus of the system under test; comprising: establishing a test network consisting of a first GJB289A terminal module as a BC and a remote terminal RT taken from the GJB289A bus of the system under test; extracting non-broadcast messages from the recorded file, converting the extracted messages into BC instructions, and sending the BC instructions to the GJB289A bus of the system under test; obtaining the address of the remote terminal based on the response of the remote terminal to the sent instruction and the instruction word converted from the current instruction; and sequentially obtaining the addresses of all remote terminals; Step 3: Obtaining simple network messages of the remote terminal; including: extracting messages related to a specified remote terminal from the recorded file, converting each of the extracted messages into instructions for BC transmission and sending them to the GJB289A bus of the system under test, recording the messages on the GJB289A bus as simple network messages of the specified remote terminal; and sequentially obtaining simple network messages of all remote terminals; Step 4, diagnostic test; including: extracting instructions from the simple network message obtained from the designated remote terminal, and sending them to the designated remote terminal through the BC, judging whether the GJB289A bus communication of the tested system is normal based on whether the designated remote terminal responds to the instructions in each simple network message; when the GJB289A bus communication of the tested system is normal, testing the status of the designated remote terminal based on the comparison between the current response and the response of the pre-recorded simple network message; completing the test of the remote terminal status of the GJB289A bus of the tested system in sequence.

2. The GJB289A bus ICD missing test method according to claim 1, characterized in that: The non-broadcast messages extracted from the recording file in step 2 include: transmission from the remote terminal to the BC, transmission from the BC to the remote terminal, and mode instruction transmission without data words.

3. The GJB289A bus ICD missing test method according to claim 2, characterized in that: Converting the extracted message into a BC instruction in step 2 includes: converting the message transmitted from the remote terminal to the BC into a sending instruction word; converting the message transmitted from the BC to the remote terminal into a receiving instruction word and a corresponding number of data words; and converting the message transmitted by the mode instruction without a data word into a mode control instruction word.

4. The GJB289A bus ICD missing test method according to claim 1, characterized in that: In step 2, when the remote terminal responds to the sent instruction within the first preset response time, the remote terminal address in the current instruction word is used as the address of the remote terminal; When the remote terminal does not respond within the second preset response time, the remote terminal address in the current instruction word is not the address of the remote terminal, and the instruction in the next message is converted and sent to the GJB289A bus of the system under test.

5. The method for testing ICD loss on the GJB289A bus according to any one of claims 1 to 3, characterized in that: In step 3, messages related to a specified remote terminal are extracted from the recorded file, including: messages transmitted from the bus controller BC to the specified remote terminal RT, messages transmitted from the specified remote terminal RT to the bus controller BC, messages that are mode instructions and the remote terminal address field in the instruction is the same as the address of the specified remote terminal RT, broadcast transmissions from the bus controller BC to each remote terminal, and messages that are broadcast mode instructions.

6. The method for testing ICD loss on the GJB289A bus according to claim 5, characterized in that: In step 3, the message related to the specified RT is extracted from the recording file and converted into a BC instruction to be sent. The conversion content includes: converting the message transmitted from BC to the specified RT into a receive instruction word with the RT address field being the specified RT address and a corresponding number of data words; converting the message transmitted from the specified RT to BC into a send instruction word with the RT address field being the specified RT address; converting the mode instruction message with the RT address being the specified RT address into a mode control instruction word, a mode instruction word, or a mode instruction word and a data word; converting the message broadcasted by BC to each RT into a receive instruction word with the RT address being 11111 and a corresponding number of data words; converting the message of the broadcast mode instruction into a mode control instruction word or a mode instruction word and a data word.

7. The method for testing ICD loss on the GJB289A bus according to claim 6, characterized in that: In step 4, the remote terminal's response to the instructions in the simple network message includes: the response to the message transmitted from the bus controller BC to the designated remote terminal RT is 1 status word; the response to the message transmitted from the designated remote terminal RT to the bus controller BC is 1 status word and a specified number of data words; the response to the message of the mode instruction and the remote terminal address field in the instruction is the same as the address of the designated remote terminal RT is 1 status word, 1 status word and 1 data word; the response to the message of the broadcast transmission and broadcast mode instruction from BC to each remote terminal is no response.

8. The method for testing ICD loss on the GJB289A bus according to claim 7, characterized in that: Step 4 also includes the step of classifying simple network messages into time-independent messages and time-dependent messages based on the remote terminal's response to instructions received. Whether the remote terminal is in a normal state is determined based on the changing pattern of whether the remote terminal responds to the time-independent message and the difference in response to instructions in the time-dependent message.

9. The method for testing ICD loss on the GJB289A bus according to claim 8, characterized in that: For time-related message instructions, the same instruction is sent multiple times to detect the changing pattern of the response difference. When the changing pattern of the response difference is consistent with the corresponding changing pattern, the remote terminal status is judged to be normal, otherwise the remote terminal status is judged to be abnormal.

10. The method for testing ICD loss on the GJB289A bus according to claim 9, characterized in that: The response difference change patterns include increasing by seconds or milliseconds, small fluctuations, or slow increases or small fluctuations after warm-up.

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