File System AT Commands

Note

  • The File System AT commands are enable by default and cannot be disabled.

  • AT+FS command performs corresponding operations in the AT directory of the file system.

  • AT+CERT command performs corresponding operations in the CERT directory of the file system.

  • AT+FSRGN command configures the file system region for the above command operations.

  • If you want to preload files, refer to Preload Example.

  • Prior to performing file write operations, validate both file system available capacity and dynamic memory free space to ensure sufficient resource allocation.

AT+FS

Function Description

Perform file system operations, including deleting files, reading files, writing files, getting file sizes, and listing files.

Command Format

AT+FS=<operation>[,<filename>,<offset>,<length>]

Response Format

Successful Response:

OK

Error Response:

ERROR: <error_no>

Parameters

<operation>:

File operation type

  • 0: List files in directory

  • 1: Delete file

  • 2: Get file size

  • 3: Read file

  • 4: Write file

<filename>:

File name string

  • Length not exceeding 125 bytes

<offset>:

Starting position for reading or writing

<length>:

Length to read or write

Error Codes

  • 1: Format error

  • 2: Operation failed

Note

When <operation> is set to write, the system will enter Transparent Transmission (TT) Mode mode.

Examples

  • List files in the directory:

    AT+FS=0

OK

  • Delete the file test.txt:

    AT+FS=1,"test.txt"

OK

  • Get size of file data.bin:

    AT+FS=2,"data.bin"
+FS: 1024

OK

  • Read 50 bytes from the file log.txt starting at offset 100:

    AT+FS=3,"log.txt",100,50
+FS: <read data>

OK

  • Write 100 bytes of data to the file new.dat:

    AT+FS=4,"new.dat",0,100
>>>
<send 100 bytes of data>

OK

AT+CERT

Function Description

Query the certificate components of the server or client

Command Format

AT+CERT=<role>,<index>

Response Format

Successful Response:

<Certificate name 1>
<Certificate content 1>

<Certificate name 2>
<Certificate content 2>

<Certificate name 3>
<Certificate content 3>

OK

Error Response:

ERROR: <error_no>

Parameters

<role>:

Certificate component type

  • 0: Client

  • 1: Server

<index>:

Certificate component index

  • Range: 1~10

Error Codes

  • 1: Parameter error

AT+FSRGN

Function Description

Configure the file system command operation region.

Command Format

AT+FSRGN=<vfs region>

Response Format

Successful Response:

OK

Error Response:

ERROR: <error_no>

Parameters

<vfs region>:

File system region - 1: region 1 - 2: region 2

Error Codes

  • 1: Parameter error