使用 ARXML 从 MDF 文件中读取数据
此示例说明如何使用 ARXML 作为数据库从 MDF 文件读取数据。
查看 MDF 文件的详细信息
使用 mdfInfo 函数查看 MDF 文件的元数据。
mdfInfo("MDF_ARXML.mf4")ans =
MDFInfo with properties:
File Details
Name: "MDF_ARXML.mf4"
Path: "C:\ExampleManager772791\user.Example_ARXMLCANDecoding\vnt-ex37098395\MDF_ARXML.mf4"
Author: ""
Department: ""
Project: ""
Subject: ""
Comment: ""
Version: "4.20"
InitialTimestamp: 2024-11-15 23:06:16.345000000
Creator Details
ProgramIdentifier: "MDF4Lib"
CreatorVendorName: "Vector Informatik GmbH"
CreatorToolName: "CANoe"
CreatorToolVersion: "18.2.65"
CreatorUserName: "siyingl"
CreatorComment: "Created using MdfLog version 1.7.7.0 and Mdf4Lib version 1.9.0.0 X64 (2022-08-31)"
File Contents
Attachment: [5×7 table]
ChannelGroupCount: 5
Event: [0×8 eventtable]
标识 CAN 数据帧
根据总线日志记录的 ASAM MDF 相关联标准，为 CAN 总线系统定义的事件类型可以是“CAN_DataFrame”、“CAN_RemoteFrame”、“CAN_ErrorFrame”或“CAN_OverloadFrame”。此示例的重点是提取 CAN 数据帧，因此将使用“CAN_DataFrame”事件类型作为示例来讨论总线日志记录标准。此外，请注意，标准 CAN 数据帧的有效负载最多包含 8 个字节，用于传输信号值。
该标准规定事件结构体的通道名称应以事件类型名称为前缀，例如“CAN_DataFrame”。通常，使用点作为分隔符来指定成员通道，例如“CAN_DataFrame.ID”或“CAN_DataFrame.DataLength”。
使用 mdfChannelInfo 函数查找与“CAN_DataFrame.*”匹配的通道名称。返回包含匹配通道信息的表。
mdfChannelInfo("MDF_ARXML.mf4", Channel="CAN_DataFrame.*")
ans=24×13 table
"CAN_DataFrame.BitCount" 2 6 CAN2 <undefined> <undefined> CAN_DataFrame "BitCount" <undefined> Frame length in bits. CAN2 <undefined> CAN2
"CAN_DataFrame.BitCount" 3 6070 CAN1 <undefined> <undefined> CAN_DataFrame "BitCount" <undefined> Frame length in bits. CAN1 <undefined> CAN1
"CAN_DataFrame.BusChannel" 2 6 CAN2 <undefined> <undefined> CAN_DataFrame "BusChannel" <undefined> Logical bus channel number the frame was sent or received. CAN2 <undefined> CAN2
"CAN_DataFrame.BusChannel" 3 6070 CAN1 <undefined> <undefined> CAN_DataFrame "BusChannel" <undefined> Logical bus channel number the frame was sent or received. CAN1 <undefined> CAN1
"CAN_DataFrame.DLC" 2 6 CAN2 <undefined> <undefined> CAN_DataFrame "DLC" <undefined> Data length code. CAN2 <undefined> CAN2
"CAN_DataFrame.DLC" 3 6070 CAN1 <undefined> <undefined> CAN_DataFrame "DLC" <undefined> Data length code. CAN1 <undefined> CAN1
"CAN_DataFrame.DataBytes" 2 6 CAN2 <undefined> <undefined> CAN_DataFrame "DataBytes" <undefined> Payload data bytes containing the signal values. CAN2 <undefined> CAN2
"CAN_DataFrame.DataBytes" 3 6070 CAN1 <undefined> <undefined> CAN_DataFrame "DataBytes" <undefined> Payload data bytes containing the signal values. CAN1 <undefined> CAN1
"CAN_DataFrame.DataLength" 2 6 CAN2 <undefined> <undefined> CAN_DataFrame "DataLength" <undefined> Length of stored payload in bytes. CAN2 <undefined> CAN2
"CAN_DataFrame.DataLength" 3 6070 CAN1 <undefined> <undefined> CAN_DataFrame "DataLength" <undefined> Length of stored payload in bytes. CAN1 <undefined> CAN1
"CAN_DataFrame.Dir" 2 6 CAN2 <undefined> <undefined> CAN_DataFrame "Dir" <undefined> Bit signal indicating the direction (Rx, Tx). CAN2 <undefined> CAN2
"CAN_DataFrame.Dir" 3 6070 CAN1 <undefined> <undefined> CAN_DataFrame "Dir" <undefined> Bit signal indicating the direction (Rx, Tx). CAN1 <undefined> CAN1
"CAN_DataFrame.Flags" 2 6 CAN2 <undefined> <undefined> CAN_DataFrame "Flags" <undefined> Combination of bit flags for the message. CAN2 <undefined> CAN2
"CAN_DataFrame.Flags" 3 6070 CAN1 <undefined> <undefined> CAN_DataFrame "Flags" <undefined> Combination of bit flags for the message. CAN1 <undefined> CAN1
⋮
感兴趣的数据是从 CAN 1 网络记录的。上面的输出显示来自 CAN 1 网络的数据已存储在 MDF 文件的通道组 3 中。通过指定 GroupNumber 选项，使用 mdfChannelGroupInfo 函数查看有关通道组 3 的详细信息。
mdfChannelGroupInfo("MDF_ARXML.mf4", GroupNumber=3)ans=1×13 table
3 CAN1 <undefined> 6070 163890 1 <undefined> CAN_DataFrame <undefined> 2 2 1 0
使用 mdfChannelInfo 查看通道组 3 中所有通道的详细信息。
mdfChannelInfo("MDF_ARXML.mf4", GroupNumber=3)ans=13×13 table
"CAN_DataFrame.BitCount" 3 6070 CAN1 <undefined> <undefined> CAN_DataFrame "BitCount" <undefined> Frame length in bits. CAN1 <undefined> CAN1
"CAN_DataFrame.BusChannel" 3 6070 CAN1 <undefined> <undefined> CAN_DataFrame "BusChannel" <undefined> Logical bus channel number the frame was sent or received. CAN1 <undefined> CAN1
"CAN_DataFrame.DLC" 3 6070 CAN1 <undefined> <undefined> CAN_DataFrame "DLC" <undefined> Data length code. CAN1 <undefined> CAN1
"CAN_DataFrame.DataBytes" 3 6070 CAN1 <undefined> <undefined> CAN_DataFrame "DataBytes" <undefined> Payload data bytes containing the signal values. CAN1 <undefined> CAN1
"CAN_DataFrame.DataLength" 3 6070 CAN1 <undefined> <undefined> CAN_DataFrame "DataLength" <undefined> Length of stored payload in bytes. CAN1 <undefined> CAN1
"CAN_DataFrame.Dir" 3 6070 CAN1 <undefined> <undefined> CAN_DataFrame "Dir" <undefined> Bit signal indicating the direction (Rx, Tx). CAN1 <undefined> CAN1
"CAN_DataFrame.Flags" 3 6070 CAN1 <undefined> <undefined> CAN_DataFrame "Flags" <undefined> Combination of bit flags for the message. CAN1 <undefined> CAN1
"CAN_DataFrame.FrameDuration" 3 6070 CAN1 <undefined> <undefined> CAN_DataFrame "FrameDuration" ns Duration for transmission of the frame in nanoseconds. CAN1 <undefined> CAN1
"CAN_DataFrame.ID" 3 6070 CAN1 <undefined> <undefined> CAN_DataFrame "ID" <undefined> ID of the CAN message. CAN1 <undefined> CAN1
"CAN_DataFrame.IDE" 3 6070 CAN1 <undefined> <undefined> CAN_DataFrame "IDE" <undefined> Identifier Extension bit. CAN1 <undefined> CAN1
"CAN_DataFrame.SingleWire" 3 6070 CAN1 <undefined> <undefined> CAN_DataFrame "SingleWire" <undefined> Bit flag indicating a single wire operation. CAN1 <undefined> CAN1
"CAN_DataFrame.WakeUp" 3 6070 CAN1 <undefined> <undefined> CAN_DataFrame "WakeUp" <undefined> Bit flag indicating a wake-up message (high voltage). CAN1 <undefined> CAN1
"t" 3 6070 CAN1 <undefined> <undefined> CAN_DataFrame "" s <undefined> CAN1 <undefined> <undefined>
从 MDF 文件读取 MDF 数据
使用 mdfRead 函数将通道组 3 中所有通道的所有数据读入一个时间表中。时间表的结构遵循 ASAM MDF 标准日志记录格式。每行表示来自总线的一个原始 CAN 帧，而每列表示指定通道组中的一个通道。
mdfData = mdfRead("MDF_ARXML.mf4", GroupNumber=3);
mdfData{1}ans=6070×12 timetable
0.050294 sec 1 1 "Tx" 0 0 2147485696 1 288000 147 8 8 [250,0,16,0,4,0,1,0]
0.050526 sec 1 1 "Tx" 0 0 3 0 226000 116 8 8 [210,236,104,118,52,187,124,192]
0.050694 sec 1 1 "Tx" 0 0 16 0 162000 84 4 4 [0,3,89,100]
0.050898 sec 1 1 "Tx" 0 0 2047 0 198000 102 6 6 [226,99,235,64,255,255]
0.051184 sec 1 1 "Tx" 0 0 2684354559 1 280000 143 8 8 [0,0,45,10,68,26,184,161]
0.10029 sec 1 1 "Tx" 0 0 2147485696 1 286000 146 8 8 [237,0,12,0,6,0,0,0]
0.10053 sec 1 1 "Tx" 0 0 3 0 236000 121 8 8 [0,56,252,27,254,13,75,64]
0.10071 sec 1 1 "Tx" 0 0 16 0 166000 86 4 4 [0,252,200,92]
0.10091 sec 1 1 "Tx" 0 0 2047 0 196000 101 6 6 [68,41,41,64,249,255]
0.1012 sec 1 1 "Tx" 0 0 2684354559 1 282000 144 8 8 [0,64,126,0,196,46,248,98]
0.15029 sec 1 1 "Tx" 0 0 2147485696 1 286000 146 8 8 [118,0,24,0,4,0,0,0]
0.15052 sec 1 1 "Tx" 0 0 3 0 226000 116 8 8 [120,21,188,10,94,69,132,64]
0.15069 sec 1 1 "Tx" 0 0 16 0 162000 84 4 4 [0,252,161,14]
0.15089 sec 1 1 "Tx" 0 0 2047 0 196000 101 6 6 [41,48,20,192,254,255]
⋮
使用 ARXML 文件对象对 CAN 报文进行解码
使用 arxmlDatabase 函数打开 ARXML 文件 DecodingExample.arxml。
arxmlObj = arxmlDatabase("DecodingExample.arxml")arxmlObj =
Database with properties:
Name: "DecodingExample.arxml"
Path: "C:\ExampleManager772791\user.Example_ARXMLCANDecoding\vnt-ex37098395\DecodingExample.arxml"
CAN: [1×1 shared.vnt.arxml.protocol.CAN]
通过调用 canMessageTimetable 函数创建解码的 CAN 报文时间表。ASAM 标准日志记录格式数据的时间表转换为 Vehicle Network Toolbox™ CAN 报文时间表。arxmlObj 用于函数的 Database 输入参量的值，该参量将提供解码数据的参考数据库信息。
decodedData = canMessageTimetable(mdfData{1}, arxmlObj)decodedData=6070×8 timetable
0.050294 sec 2048 1 'Frame2' [250,0,16,0,4,0,1,0] 8 1×1 struct 0 0
0.050526 sec 3 0 'Frame4' [210,236,104,118,52,187,124,192] 8 1×1 struct 0 0
0.050694 sec 16 0 'Frame5' [0,3,89,100] 4 1×1 struct 0 0
0.050898 sec 2047 0 'Frame1' [226,99,235,64,255,255] 6 1×1 struct 0 0
0.051184 sec 536870911 1 'Frame3' [0,0,45,10,68,26,184,161] 8 1×1 struct 0 0
0.10029 sec 2048 1 'Frame2' [237,0,12,0,6,0,0,0] 8 1×1 struct 0 0
0.10053 sec 3 0 'Frame4' [0,56,252,27,254,13,75,64] 8 1×1 struct 0 0
0.10071 sec 16 0 'Frame5' [0,252,200,92] 4 1×1 struct 0 0
0.10091 sec 2047 0 'Frame1' [68,41,41,64,249,255] 6 1×1 struct 0 0
0.1012 sec 536870911 1 'Frame3' [0,64,126,0,196,46,248,98] 8 1×1 struct 0 0
0.15029 sec 2048 1 'Frame2' [118,0,24,0,4,0,0,0] 8 1×1 struct 0 0
0.15052 sec 3 0 'Frame4' [120,21,188,10,94,69,132,64] 8 1×1 struct 0 0
0.15069 sec 16 0 'Frame5' [0,252,161,14] 4 1×1 struct 0 0
0.15089 sec 2047 0 'Frame1' [41,48,20,192,254,255] 6 1×1 struct 0 0
⋮
来自 CAN 原始报文的解码信号存储在 Signals 列中。
decodedData.Signals{1}ans = struct with fields:
Signal5: 27
Signal11: 7
重新打包并可视化感兴趣的信号值
使用 canSignalTimetable 观测信号值。该示例将检查 Frame2 中 Signal5 的值。
signalTimetable = canSignalTimetable(decodedData, "Frame2")signalTimetable=1214×2 timetable
0.050294 sec 27 7
0.10029 sec 20.5000 6.5000
0.15029 sec 89 8
0.20029 sec -22 8
0.25029 sec 68 7
0.30029 sec 10.5000 7
0.35029 sec -19 7.5000
0.40029 sec 13 6
0.4503 sec 40.5000 5.5000
0.50029 sec 51.5000 6.5000
0.55029 sec -4 6.5000
0.60029 sec -8 6.5000
0.65029 sec -14 5.5000
0.70029 sec -28 6.5000
⋮
为了可视化感兴趣的信号，可以绘制信号时间表中的列随时间变化的图，以便进一步分析。该图将显示 Signal5 的前 5 秒值。
plot(signalTimetable.Time, signalTimetable.Signal5); xlim(seconds([0 5]));
关闭 ARXML 文件
通过从工作区中清除 ARXML 文件的变量，关闭对该 ARXML 文件的访问。
clear arxmlObj
