JP5354450B2 - Waveform measuring device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a waveform measuring device capable of efficient setting between respective serial analysis functions. <P>SOLUTION: The waveform measuring device executes serial analysis functions including trigger/search/analysis to data transmitted through a serial bus while displaying the waveform of the data as an analog waveform. The device includes a serial analysis execution means for automatically executing at least one of the search function and the trigger function based on flame information analyzed by the analysis function. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a waveform measuring apparatus, and more particularly to waveform analysis in a serial bus.

  Serial communication is a communication method for continuously transmitting digital data bit by bit, and serial buses based on various communication protocols (protocols) such as RS232C, USB, CAN, LIN, and FlexRay have been put into practical use. In such serial communication, trouble may occur due to noise due to surge voltage or level fluctuation due to overload after connection. In analyzing these troubles, it is necessary to analyze the physical layer (serial bus communication path).

  Therefore, as a device for analyzing data while displaying the waveform of data transmitted via the serial bus as an analog waveform, for example, a waveform measuring device as shown in FIG. 11 has been proposed. In FIG. 11, the input signal Din is separated by the trigger circuit 1 from data that matches the trigger condition, and is input to the A / D converter 2 and quantized. The output data quantized by the A / D converter 2 is stored in the data memory 3.

  The data stored in the data memory 3 is displayed on the display device 4 and transferred and stored in the external memory 5 as necessary. The external memory 5 is also used as a backup data storage destination. The search circuit 6 searches and extracts the data stored in the data memory 3 based on the search condition set according to the measurement purpose, and displays the search result on the display device 4. The CPU 7 comprehensively controls the operation of each part of the waveform measuring apparatus configured as described above.

  Japanese Patent Application Laid-Open No. 2004-151561 describes a method for measuring a waveform of serial communication data and a configuration of an apparatus.

JP 2007-205751 A

  By the way, such a waveform measuring apparatus for analyzing data transmitted via the serial bus has a serial analysis function such as trigger / search / analysis specialized for the serial bus. Items such as a bit rate and a threshold level that are common between these serial analysis functions are linked, and if a certain function is set, there is no need to reset it by another function. For example, setting the bit rate with the trigger function is also reflected in the bit rate of the search and analysis functions.

  In general, most of these linkage settings are considered to be used in linkage. However, in exceptional cases, it may be possible to set each function independently, so “link / do not link” can be selected. ing.

  However, in the conventional device, although items such as bit rate and threshold level that exist in common among each serial analysis function are linked, other complicated triggers and search settings are not considered. There is a problem that complicated settings must be made each time.

  The present invention has been made in view of such problems, and an object of the present invention is to realize a waveform measuring apparatus capable of efficiently performing setting between serial analysis functions.

In order to solve such a problem, the invention of claim 1
In a waveform measurement device configured to execute a serial analysis function including trigger / search / analysis for data while displaying a waveform of data transmitted via a serial bus as an analog waveform,
Serial analysis execution means for automatically executing at least one of the search function and the trigger function based on the frame information analyzed by the analysis function;
It is characterized by having.

The invention according to claim 2 is the waveform measuring apparatus according to claim 1,
The search result in the serial analysis is linked to a trigger condition.

The invention according to claim 3 is the waveform measuring apparatus according to claim 1,
The parameter measurement result in the serial analysis is linked to a trigger condition.

The invention according to claim 4 is the waveform measuring apparatus according to any one of claims 1 to 3,
The serial analysis execution means includes
A frame immediately before error selecting a frame immediately before the searched error frame;
A list storage unit for storing a list of values of each parameter of the frame immediately before the error selected by the frame immediately before error selected;
Trigger condition automatic setting unit that automatically sets the value of each parameter stored in this list storage unit as a trigger condition,
It is characterized by including.

  According to these waveform measuring apparatuses, settings between the respective serial analysis functions can be performed efficiently.

  The present invention will be described below with reference to the drawings. FIG. 1 is a data frame format example of a CAN (Can Area Network) protocol. In FIG. 1, SOF (Start Of Frame) is a bit indicating the head of a frame. The arbitration field is composed of an 11-bit ID (Identifier), and a 1-bit RTR (Remote Transmission Request Bit) is placed after the ID. The control field is composed of an IDE bit, an RBO bit, and a DLC bit. The data field is composed of 8N (0 ≦ N ≦ 8) bits. The CRC field is composed of a 15-bit CRC (Cyclic Redundancy Check) code and a 1-bit CRC boundary. The ACK field is composed of a 1-bit ACK and a 1-bit ACK boundary. EOF (End Of Frame) indicates the end of the frame, and is composed of 7 bits.

  In such a frame configuration, by selecting a field of interest (for example, SOF, arbitration field, ID, etc.) as a trigger target, a trigger is applied at a preset trigger condition point. The data field contains information that has meaning depending on the application, such as the rotation speed and speed.

  FIG. 2 is a block diagram showing a configuration example of a main part of the waveform measuring apparatus according to the present invention, and shows functional blocks in the CPU 7 of FIG. In FIG. 2, the frame immediately before error selection unit 71 selects a frame immediately before the error frame searched by the search circuit 6.

  The list storage unit 72 stores the values of the parameters of the frame immediately before the error selected by the frame immediately before error selected in the list.

  The trigger condition automatic setting unit 73 automatically sets each parameter value of the frame immediately before the error selected by the frame immediately before error selection unit 71 and stored in the list storage unit 72 as a trigger condition.

  The frame number determination unit 74 determines the number of frames for the frames captured based on the trigger condition set by the trigger condition automatic setting unit 73.

  The error frame detection unit 75 detects whether or not the frame captured based on the trigger condition set by the trigger condition automatic setting unit 73 is an error frame.

  The symbolic database 76 stores various parameters such as ID, FrameType, DLC, Data comparison condition, ByteOrder, Sign, MSB / LSB.

  If the frame captured based on the trigger condition set by the trigger condition automatic setting unit 73 is not an error frame, the frame ID comparison unit 77 compares whether the frame ID matches the symbolic database.

  The mode setting unit 78 sets the mode corresponding to each according to the comparison result of the frame ID comparison unit 77.

  The parameter setting unit 79 sets the value of each parameter stored in the symbolic database 76 or the list storage unit 72 according to the set mode.

  The operation of a specific example will be described. For example, it is assumed that a problem of unknown cause has occurred on the CAN bus mounted on the vehicle. Under the situation where even the trigger condition is unknown even if the trigger is applied, first, in order to grasp the outline of the state of the CAN bus, as shown in FIG. 3, the data frame flowing in the CAN bus is observed.

  FIG. 3 is an example of the frame analysis screen of FIG. 1 based on the analysis function of the serial analysis function. In FIG. 3, a decoding result area DA is provided immediately below the waveform display area WA, and a list display area LA is provided further below. List contents include No (serial number), Frame (frame type [Data / Remote frame]), Time (time from reference point), ID / Msg (ID field in FIG. 1), frame length (DLC in FIG. 1). ), Data (Data field in FIG. 1), CRC (CRC in FIG. 1), and presence / absence of Ack (ACK in FIG. 1).

  For example, as shown in FIG. 4, it is assumed that an error frame is visually found in the list. Here, when the reason why the error frame is generated is unknown, the frame around the error frame is observed and estimated. In order to do so, it is necessary to find out the location where the error frame has occurred, so a search is performed using the error frame as a search condition as shown in the search function menu screen of FIG.

  In the conventional configuration, the manual operation is used to go to the search menu → set the mode to error frame → search execution, but in the present invention, only the frame in the list where the error has occurred is selected. , Automatically go to the search menu and the mode is set to error frame.

  As a specific example, it is assumed that, for example, as a result of searching with the search function, it is estimated that the ID of the frame immediately before the error is only 0 Ah. In order to confirm this assumption, it is necessary to perform a long-time observation by triggering with ID: 0 Ah.

  In the case of the conventional configuration, the sequence of moving to the trigger menu, setting the mode to “ID / Data”, setting the ID pattern, and starting the measurement is performed manually.

  On the other hand, in the present invention, the frame immediately before the error in the list is selected by the frame immediately before error selection unit 71 to automatically move to the trigger menu, and the trigger mode is set to “ID / Data”. .

  As a result, as shown in the correspondence relationship between the analysis screen of FIG. 6 and the trigger function menu screen of FIG. 7, each parameter of the frame immediately before the error displayed on the analysis screen of FIG. 6 as each parameter of the trigger function is displayed. The values P1 to P4 are displayed in the respective item columns of the trigger function menu screen of FIG. 7 and are automatically set as trigger conditions.

  If a trigger is to be applied under the OR condition, “ID / Data OR” is automatically set when multiple selections are made.

  If you want to change the setting arbitrarily, you can reset it manually.

  FIG. 8 is a flowchart showing the flow of the process of FIG. 2 when selecting frame information according to the present invention. First, the frame number determination unit 74 determines whether or not there are a plurality of frames taken in based on the trigger condition set by the trigger condition automatic setting unit 73 (SP1).

  In the case of a plurality of frames, the error frame detection unit 75 determines whether or not an error frame is included (SP2). If an error frame is included, an error is displayed (SP3) and the process ends. Further, if it is not a plurality of frames, the error frame detection unit 75 determines whether or not it is an error frame (SP4). In the case of an error frame, the mode setting unit 78 sets the mode to an error frame (SP5) and ends.

  If it is not an error frame, the frame ID comparison unit 77 determines whether or not the frame ID matches the symbolic DB (database) (SP6). If they match, the mode setting unit 78 sets the mode to Msg / Signal (SP7), the parameter setting unit 79 sets various parameters (SP8), and the process ends.

Here, the parameter setting unit 79 reads and sets the following parameters from the symbolic database 76 as various parameters.
・ ID
・ FrameType: Data
・ DLC
-Data comparison condition: Numerical comparison-ByteOrder
・ Sign
・ MSB / LSB
In addition, when a plurality of frames are selected on the list LA, it is set as an OR of a plurality of conditions.

  If the frame ID does not match the symbolic DB (database), the mode setting unit 78 sets the mode to ID / Data (SP9), the parameter setting unit 79 sets various parameters (SP10), and the process ends. .

Here, the parameter setting unit 79 reads and sets the following parameters from the frame information of the list as various parameters.
・ ID
・ FrameType
・ DLC
・ Data comparison condition: True / False
・ ACK
When a plurality of frames are selected on the list LA, the mode setting unit 78 sets the mode to ID / Data OR and sets it as an OR of a plurality of conditions.

  As described above, according to the present invention, serial analysis can be performed automatically and seamlessly based on the frame information analyzed by the analysis function without knowing the detailed settings of the search function and the trigger function. .

  In the above embodiment, the example in which the search result is linked to the trigger condition has been described. However, the search result may be linked to the trigger condition from the parameter measurement result. For example, there is a parameter “+ Width” that measures the time interval above the rectangular wave. As shown in Fig. 9, this parameter is measured at the periodic interval of the measured waveform and displayed in the list display area LA is one of the analysis functions (the maximum value of the measurement result is displayed as ↑ and the minimum value is displayed as ↓. ).

  For example, when the tenth measurement result “9.808 ms” in the list of FIG. 9 is selected as the parameter P5, as shown in FIG. 10, the time parameter P5 of the width trigger / search menu is set to “9.808 ms” in the Time area. "Is automatically set. Here, in the example of FIG. 10, since the mode is set to “More than”, the trigger / search is performed with a width of 9.808 ms or more.

  As described above, according to the present invention, setting between each serial analysis function can be performed efficiently, so that a waveform measuring apparatus capable of efficiently performing waveform analysis on the serial bus can be realized.

It is a data frame format example figure of a CAN protocol. It is a block diagram which shows the structural example of the principal part of the waveform measuring device based on this invention. It is an example of the analysis screen of the flame | frame of FIG. 1 based on an analysis function. It is an example screen figure when an error frame is found. It is a menu screen example figure of a search function. It is an example of an analysis screen related to error frame search. It is a menu screen example figure of a trigger function. It is a flowchart which shows the flow of the process of FIG. 2 at the time of the frame information selection based on this invention. It is another example of a display screen based on an analysis function. FIG. 10 is an example menu screen of a trigger function related to FIG. 9. It is a block diagram which shows an example of the conventional waveform measuring apparatus which has a serial analysis function.

Explanation of symbols

1 trigger circuit 2 A / D converter 3 data memory 4 display device 5 external memory 6 search circuit 7 CPU
71 Frame selection section immediately before error 72 List storage section 73 Automatic trigger condition setting section 74 Frame number determination section 75 Error frame detection section 76 Symbolic database 77 Frame ID comparison section 78 Mode setting section 79 Parameter setting section

Claims (4)

In a waveform measurement device configured to execute a serial analysis function including trigger / search / analysis for data while displaying a waveform of data transmitted via a serial bus as an analog waveform,
Serial analysis execution means for automatically executing at least one of the search function and the trigger function based on the frame information analyzed by the analysis function;
A waveform measuring apparatus comprising:   The waveform measurement apparatus according to claim 1, wherein a search result in the serial analysis is linked to a trigger condition.   The waveform measurement apparatus according to claim 1, wherein a parameter measurement result in the serial analysis is linked to a trigger condition. The serial analysis execution means includes
A frame immediately before error selecting a frame immediately before the searched error frame;
A list storage unit for storing a list of values of each parameter of the frame immediately before the error selected by the frame immediately before error selected;
Trigger condition automatic setting unit that automatically sets the value of each parameter stored in this list storage unit as a trigger condition,
The waveform measuring apparatus according to claim 1, wherein the waveform measuring apparatus includes: