4. File saving
Note: GCAN-401 only supports a maximum capacity of 32G and the file system is FAT32 format of TF card, if your TF card is not the FAT32, the card must be reformatted into FAT32 format, data will be removed, please careful operation.
TF card is full of files that are not automatically overwritten.If the time interval between frames is 1 ms,the data can be stored for 24 days(32GTFcard).
GCAN-401 has integrated system clock, system clock and file system can record data by date.
GCAN-401 will create folder every day named by date. Bus data will be automatically deposited in the corresponding folder.
GCAN-401 will create a new file per minute, data will saved to the corresponding file. Shown in figure 4.1

GCAN-401 supports two kinds of saving data format: text file (TXT), binary files (DAT), through NO.7 code switch, as shown in figure 4.2.

Switch to preserve up into a text document format (TXT), switch to preserve down into the binary file format (DAT).
4.1 Example for text document format (TXT)
TXT file saved data content as shown in figure 4.3.

When users selects save into a text file format, the specific data as shown below:
The first column: time interval between frames, precision: 0.1ms (6 characters)
The second column: frame info (2 characters, please refer to the appendix B for the specific meaning）
The third column: frame ID (8 characters)
The fourth column: frame data
4.2 Example for binary file format (DAT)
DAT file saved data content as shown in figure 4.4.

When users selects save into a binary file format, the specific data as shown below:
The first second third byte: time interval between frames, precision: 0.1ms
The fourth byte: frame info (2 characters, please refer to the appendix B for the specific meaning）
The fifth sixth seventh eighth byte: frame ID
After ninth bytes：frame data