在 MDF 文件中导入和解码 LIN 数据
此示例说明如何在 MATLAB® 中从 MDF 文件导入和解码 LIN 数据以进行分析。另一个示例说明如何从 MDF 文件中提取 CAN 和 CAN FD 总线数据并对它们进行解码（将时间表数据写入 MDF 文件时自定义元数据）。在此处，您将学习如何访问 LIN 帧并使用 LDF 文件对它们进行解码。此示例中使用的 MDF 文件是使用 Vector CANoe™ 生成的，解码由与 CAN-LIN 网络设置关联的 LIN 描述文件 (LDF) 之一提供。
标识 LIN 数据帧
首先，收集有关 MDF 文件的信息：
mdfInfo("MDFFrameLogging.mf4")ans =
MDFInfo with properties:
File Details
Name: "MDFFrameLogging.mf4"
Path: "/tmp/Bdoc25b_2988451_1430519/tpe4ace63d/vnt-ex95179185/MDFFrameLogging.mf4"
Author: ""
Department: ""
Project: ""
Subject: ""
Comment: ""
Version: "4.20"
InitialTimestamp: 2025-01-16 19:44:41.936000000
Creator Details
ProgramIdentifier: "MDF4Lib"
CreatorVendorName: "Vector Informatik GmbH"
CreatorToolName: "CANoe"
CreatorToolVersion: "18.2.65"
CreatorUserName: "hpatel"
CreatorComment: "Created using MdfLog version 1.7.7.0 and Mdf4Lib version 1.9.0.0 X64 (2022-08-31)"
File Contents
Attachment: [10×7 table]
ChannelGroupCount: 18
Event: [0×8 eventtable]
根据 ASAM MDF 总线记录标准，LIN 总线系统的事件类型包括 "LIN_Frame"、"LIN_WakeUp"、"LIN_TransmissionError"、"LIN_SyncError"、"LIN_ReceiveError"、"LIN_Spike" 或 "LIN_LongDom"。此示例的重点是使用 "LIN_Frame" 事件类型提取 LIN 数据帧。一个标准 LIN 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中的通道名称应以事件类型名称为前缀，例如 "LIN_Frame"。通常，使用点作为分隔符来指定成员通道，例如 "LIN_Frame.ID" 或 "LIN_Frame.DataLength"。
使用 mdfChannelInfo 函数查找与 "LIN_Frame.*" 匹配的通道名称：
mdfChannelInfo("MDFFrameLogging.mf4", Channel="LIN_Frame.*")
ans=66×13 table
Name GroupNumber GroupNumSamples GroupAcquisitionName GroupComment GroupSourceName GroupSourcePath DisplayName Unit Comment ExtendedNamePrefix SourceName SourcePath
________________________________ ___________ _______________ ____________________ ____________ _______________ _______________ ______________________ ___________ __________________________________________________________ __________________ ___________ __________
"LIN_Frame.Baudrate" 11 285 LIN6 <undefined> <undefined> LIN_Frame "Baudrate" bit/second Baudrate in bits per second. LIN6 <undefined> LIN6
"LIN_Frame.Baudrate" 12 939 LIN4 <undefined> <undefined> LIN_Frame "Baudrate" bit/second Baudrate in bits per second. LIN4 <undefined> LIN4
"LIN_Frame.Baudrate" 13 1281 LIN3 <undefined> <undefined> LIN_Frame "Baudrate" bit/second Baudrate in bits per second. LIN3 <undefined> LIN3
"LIN_Frame.BreakDelimiterLength" 11 285 LIN6 <undefined> <undefined> LIN_Frame "BreakDelimiterLength" ns Length of the break delimiter in ns. LIN6 <undefined> LIN6
"LIN_Frame.BreakDelimiterLength" 12 939 LIN4 <undefined> <undefined> LIN_Frame "BreakDelimiterLength" ns Length of the break delimiter in ns. LIN4 <undefined> LIN4
"LIN_Frame.BreakDelimiterLength" 13 1281 LIN3 <undefined> <undefined> LIN_Frame "BreakDelimiterLength" ns Length of the break delimiter in ns. LIN3 <undefined> LIN3
"LIN_Frame.BreakLength" 11 285 LIN6 <undefined> <undefined> LIN_Frame "BreakLength" ns Length of the break in ns. LIN6 <undefined> LIN6
"LIN_Frame.BreakLength" 12 939 LIN4 <undefined> <undefined> LIN_Frame "BreakLength" ns Length of the break in ns. LIN4 <undefined> LIN4
"LIN_Frame.BreakLength" 13 1281 LIN3 <undefined> <undefined> LIN_Frame "BreakLength" ns Length of the break in ns. LIN3 <undefined> LIN3
"LIN_Frame.BusChannel" 11 285 LIN6 <undefined> <undefined> LIN_Frame "BusChannel" <undefined> Logical bus channel number the frame was sent or received. LIN6 <undefined> LIN6
"LIN_Frame.BusChannel" 12 939 LIN4 <undefined> <undefined> LIN_Frame "BusChannel" <undefined> Logical bus channel number the frame was sent or received. LIN4 <undefined> LIN4
"LIN_Frame.BusChannel" 13 1281 LIN3 <undefined> <undefined> LIN_Frame "BusChannel" <undefined> Logical bus channel number the frame was sent or received. LIN3 <undefined> LIN3
"LIN_Frame.Checksum" 11 285 LIN6 <undefined> <undefined> LIN_Frame "Checksum" <undefined> Checksum. LIN6 <undefined> LIN6
"LIN_Frame.Checksum" 12 939 LIN4 <undefined> <undefined> LIN_Frame "Checksum" <undefined> Checksum. LIN4 <undefined> LIN4
"LIN_Frame.Checksum" 13 1281 LIN3 <undefined> <undefined> LIN_Frame "Checksum" <undefined> Checksum. LIN3 <undefined> LIN3
"LIN_Frame.ChecksumModel" 11 285 LIN6 <undefined> <undefined> LIN_Frame "ChecksumModel" <undefined> ChecksumModel. LIN6 <undefined> LIN6
⋮
在本例中，感兴趣的外灯数据是从 LIN 4 网络记录的。上面的输出显示来自 LIN 4 网络的数据已存储在 MDF 文件的通道组 12 中。
从 MDF 文件读取 LIN 数据帧
使用 mdfRead 函数将通道组 12 中所有通道的所有数据读入一个时间表中。时间表遵循 ASAM MDF 标准记录格式，其中每行表示来自总线的一个原始 LIN 帧，每列表示指定通道组中的一个通道。
data = mdfRead("MDFFrameLogging.mf4", GroupNumber = 12)data = 1×1 cell array
{939×22 timetable}
linData = data{1}linData=939×22 timetable
t LIN_Frame.BusChannel LIN_Frame.ID LIN_Frame.Dir LIN_Frame.ReceivedDataByteCount LIN_Frame.DataLength LIN_Frame.DataBytes LIN_Frame.Checksum LIN_Frame.ChecksumModel LIN_Frame.SOF LIN_Frame.Baudrate LIN_Frame.ResponseBaudrate LIN_Frame.ConfiguredBaudrate LIN_Frame.BreakLength LIN_Frame.BreakDelimiterLength LIN_Frame.IsSimulated LIN_Frame.SupplierID LIN_Frame.MessageID LIN_Frame.NAD LIN_Frame.EOH LIN_Frame.IsETF LIN_Frame.ETFAssocIndex LIN_Frame.ETFAssocETFId
___________ ____________________ ____________ _____________ _______________________________ ____________________ _________________________________ __________________ _______________________ _____________ __________________ __________________________ ____________________________ _____________________ ______________________________ _____________________ ____________________ ___________________ _____________ _____________ _______________ _______________________ _______________________
0.10573 sec 4 21 "Tx" 6 6 {[ 255 0 255 206 255 255]} 219 "Enhanced" 100000000 19200 0 0 937494 104166 1 0 0 0 102083320 0 0 255
0.1125 sec 4 22 "Tx" 8 8 {[254 0 255 255 255 255 161 255]} 136 "Enhanced" 105729130 19200 0 0 937494 104166 1 0 0 0 107812450 0 0 255
0.11875 sec 4 25 "Tx" 7 7 {[ 224 0 255 247 255 255 203]} 193 "Enhanced" 112499920 19200 0 0 937494 104166 1 0 0 0 114583240 0 0 255
0.12187 sec 4 26 "Tx" 1 1 {[ 244]} 240 "Enhanced" 118749880 19200 0 0 937494 104166 1 0 0 0 120833200 0 0 255
0.20625 sec 4 23 "Tx" 7 7 {[ 0 254 34 255 255 255 255]} 71 "Enhanced" 200000000 19200 0 0 937494 104166 1 0 0 0 202083320 0 0 255
0.21146 sec 4 24 "Tx" 5 5 {[ 16 254 55 255 255]} 224 "Enhanced" 206249960 19200 0 0 937494 104166 1 0 0 0 208333280 0 0 255
0.21562 sec 4 27 "Tx" 3 3 {[ 253 4 170]} 247 "Enhanced" 211458260 19200 0 0 937494 104166 1 0 0 0 213541580 0 0 255
0.22135 sec 4 21 "Tx" 6 6 {[ 255 0 255 235 255 255]} 190 "Enhanced" 215624900 19200 0 0 937494 104166 1 0 0 0 217708220 0 0 255
0.22812 sec 4 22 "Tx" 8 8 {[ 253 0 255 255 255 255 52 255]} 246 "Enhanced" 221354030 19200 0 0 937494 104166 1 0 0 0 223437350 0 0 255
0.23437 sec 4 25 "Tx" 7 7 {[ 224 0 255 247 255 255 122]} 19 "Enhanced" 228124820 19200 0 0 937494 104166 1 0 0 0 230208140 0 0 255
0.2375 sec 4 26 "Tx" 1 1 {[ 236]} 248 "Enhanced" 234374780 19200 0 0 937494 104166 1 0 0 0 236458100 0 0 255
0.30573 sec 4 21 "Tx" 6 6 {[ 252 0 255 36 255 255]} 137 "Enhanced" 300000000 19200 0 0 937494 104166 1 0 0 0 302083320 0 0 255
0.3125 sec 4 22 "Tx" 8 8 {[253 0 255 255 255 255 116 255]} 182 "Enhanced" 305729130 19200 0 0 937494 104166 1 0 0 0 307812450 0 0 255
0.31875 sec 4 25 "Tx" 7 7 {[ 224 0 255 247 255 255 108]} 33 "Enhanced" 312499920 19200 0 0 937494 104166 1 0 0 0 314583240 0 0 255
0.32187 sec 4 26 "Tx" 1 1 {[ 236]} 248 "Enhanced" 318749880 19200 0 0 937494 104166 1 0 0 0 320833200 0 0 255
0.40625 sec 4 23 "Tx" 7 7 {[ 0 254 128 255 255 255 255]} 232 "Enhanced" 400000000 19200 0 0 937494 104166 1 0 0 0 402083320 0 0 255
⋮
使用 LDF 文件对 LIN 报文进行解码
使用 linDatabase 函数打开 LDF 文件。
ldb = linDatabase("ExteriorLight_LIN_CH4.ldf")ldb =
Database with properties:
File Information
Name: "ExteriorLight_LIN_CH4.ldf"
Path: "/tmp/Bdoc25b_2988451_1430519/tpe4ace63d/vnt-ex95179185/ExteriorLight_LIN_CH4.ldf"
ProtocolVersion: 2.2000
LanguageVersion: 2.2000
BusSpeed: 19.2000
Network Information
Nodes: [6×3 table]
Frames: [7×5 table]
Signals: [19×5 table]
linMessageTimetable 函数使用 LDF 数据库来解码报文名称和信号。将 ASAM 标准记录格式数据转换为 Vehicle Network Toolbox™ LIN 报文时间表。
msgTimetable = linMessageTimetable(linData, ldb)
msgTimetable=939×8 timetable
Time ID Name Data Length Signals ErrorType ChecksumType Checksum
___________ __ ___________ ____________________________________________________ ______ ____________ _________ ____________ ________
0.10573 sec 21 DLFLeft_01 255 0 255 206 255 255 0 0 6 {1×1 struct} None Enhanced 219
0.1125 sec 22 DLFRight_01 254 0 255 255 255 255 161 255 8 {1×1 struct} None Enhanced 136
0.11875 sec 25 GWE_01 224 0 255 247 255 255 203 0 7 {1×1 struct} None Enhanced 193
0.12187 sec 26 GWE_02 244 0 0 0 0 0 0 0 1 {1×1 struct} None Enhanced 240
0.20625 sec 23 DLRLeft_01 0 254 34 255 255 255 255 0 7 {1×1 struct} None Enhanced 71
0.21146 sec 24 DLRRight_01 16 254 55 255 255 0 0 0 5 {1×1 struct} None Enhanced 224
0.21562 sec 27 WWS_01 253 4 170 0 0 0 0 0 3 {1×1 struct} None Enhanced 247
0.22135 sec 21 DLFLeft_01 255 0 255 235 255 255 0 0 6 {1×1 struct} None Enhanced 190
0.22812 sec 22 DLFRight_01 253 0 255 255 255 255 52 255 8 {1×1 struct} None Enhanced 246
0.23437 sec 25 GWE_01 224 0 255 247 255 255 122 0 7 {1×1 struct} None Enhanced 19
0.2375 sec 26 GWE_02 236 0 0 0 0 0 0 0 1 {1×1 struct} None Enhanced 248
0.30573 sec 21 DLFLeft_01 252 0 255 36 255 255 0 0 6 {1×1 struct} None Enhanced 137
0.3125 sec 22 DLFRight_01 253 0 255 255 255 255 116 255 8 {1×1 struct} None Enhanced 182
0.31875 sec 25 GWE_01 224 0 255 247 255 255 108 0 7 {1×1 struct} None Enhanced 33
0.32187 sec 26 GWE_02 236 0 0 0 0 0 0 0 1 {1×1 struct} None Enhanced 248
0.40625 sec 23 DLRLeft_01 0 254 128 255 255 255 255 0 7 {1×1 struct} None Enhanced 232
⋮
查看第一个 "GWI_01" 报文中存储的信号。
msgTimetable.Signals{3}ans = struct with fields:
GWE_TurnIndicationLeft: 0
GWE_TurnIndicationRight: 0
GWE_WarningLight: 0
GWE_DrivingLight: 1
GWE_Reserved: 203
重新打包并可视化感兴趣的信号值
要将来自总线上每个唯一报文的信号数据组织为一个信号时间表，请使用此示例附带的 hLINSignalTimetable 辅助函数。此示例说明如何为 LIN 报文时间表中感兴趣的特定报文 "GWI_01" 创建信号时间表。"GWI_01" 报文包括以下信号：左转、右转、警告/危险灯和驾驶灯。
signalTimetable = hLINSignalTimetable(msgTimetable,'GWE_01')signalTimetable=171×5 timetable
Time GWE_TurnIndicationLeft GWE_TurnIndicationRight GWE_WarningLight GWE_DrivingLight GWE_Reserved
___________ ______________________ _______________________ ________________ ________________ ____________
0.11875 sec 0 0 0 1 203
0.23437 sec 0 0 0 1 122
0.31875 sec 0 0 0 1 108
0.43437 sec 0 0 0 1 248
0.51875 sec 0 0 0 1 199
0.63437 sec 0 0 0 1 197
0.71875 sec 0 0 0 1 245
0.83437 sec 0 0 0 1 119
0.91875 sec 0 0 0 1 67
1.0344 sec 0 0 0 1 198
1.1187 sec 0 0 0 1 86
1.2344 sec 0 0 0 1 14
1.3187 sec 0 0 0 1 134
1.4344 sec 0 0 0 1 233
1.5187 sec 0 0 0 1 153
1.6344 sec 0 0 0 1 26
⋮
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。
stackedplot(signalTimetable,{"GWE_TurnIndicationLeft","GWE_TurnIndicationRight","GWE_WarningLight","GWE_DrivingLight"},marker=".")
title("Signals from 'GWE\_01' Message")
