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User Manual
© 2017 Inertial Sense, LLC 26 11/30/2017
9 Data Logging
Inertial Sense provides data loggers written in C++ , which can read and write data in various formats to file. These
loggers are useful for storing, replaying, and analyzing data. SDK/src/ISLogger.h defines the logging interface.
9.1 Log File
The data log file name has the format LOG_SNXXXXX_YYYYMMDD_HHMMSS_CNT.dat which contains the device
serial number, date, time, and log file count. The two primary log file formats are .dat and .sdat. These log files
consist of a series of data Chunks.
Data Log File
(.dat or .sdat)
=
CHUNK
1
CHUNK
2
CHUNK
3
CHUNK
4
…
CHUNK
N
Standard data types are stored in the log files and are defined as:
U32 unsigned int
U16 unsigned short
S8 char
U8 unsigned char
9.1.1 Log Chunk
The data log file is composed of Chunks. A Chunk is a data container that provides an efficient method for
organizing, handling, and parsing data in a file. A Chunk starts with a header which has a unique identifiable
marker and ends with the data to be stored.
CHUNK =
CHUNK
Header CHUNK
Data
Byte Size 40
9.1.2 Chunk Header
The header, found at the start of each Chunk, is as follows:
CHUNK
Header
= Marker Version Classification Name
Name
Inverted
Data
Size
Data
Size
Inverted
Group
Number
Device
Serial
#
Port
Handle
Reserved
Byte Size 4 2 2 4 4 4 4 4 4 4 4
Data Type
U32 U16 U16 S8 (x4) S8 (x4) U32 U32 U32 U32 U32 U32
The C structure implementation of the Chunk header is:
//!< Chunk Header
#pragma pack ( push , 1)
struct sChunkHeader
{
Unsigned int marker ; //!< Chunk marker (0xFC05EA32)
unsigned short version ; //!< Chunk Version
unsigned short classification ; //!< Chunk classification
char name [4]; //!< Chunk name
char invName [4]; //!< Bitwise inverse of chunk name
unsigned int dataSize ; //!< Chunk data length in bytes
unsigned int invDataSize ; //!< Bitwise inverse of chunk data length
unsigned int grpNum ; //!< Chunk group number: 0=serial data, 1=sorted data
unsigned int devSerialNum ; //!< Device serial number
unsigned int pHandle ; //!< Device port handle
unsigned int reserved ; //!< Unused
};
#pragma pack ( pop )