Component: FAT (SCADA) (Storage)
| Author | Matrix TSL |
| Version | 1.0 (Release) |
| Category | Storage |
Contents
- 1 FAT (SCADA) component
- 2 Examples
- 3 Downloadable macro reference
- 3.1 ReadStringFromFile
- 3.2 MoveToNextFileSector
- 3.3 WriteByteToBuffer
- 3.4 AppendByteToFile
- 3.5 ReadFileSector
- 3.6 ReadByteFromFile
- 3.7 DeleteFile
- 3.8 ReadByteFromIndex
- 3.9 CreateFile
- 3.10 ScanCurrentFolder
- 3.11 ReadByteFromScan
- 3.12 OpenFolder
- 3.13 ReadByteFromBuffer
- 3.14 ReadFileLength
- 3.15 OpenFile
- 3.16 WriteFileSector
- 3.17 SetFileIndex
- 3.18 AppendStringToFile
- 3.19 ReadFileSize
- 3.20 SetTimeAndDate
- 3.21 Initialise
- 4 Simulation macro reference
- 5 Property reference
FAT (SCADA) component
FAT component allowing access to read and write files on the local Windows file system.
Examples
No additional examples
Downloadable macro reference
ReadStringFromFile
Reads a string from the currently open file. Auto increments the position in the file.
An empty string signifies the end of the file has been reached.
Parameters
- BYTE NumBytes
- Maximum number of bytes to attempt to read
- BYTE EndChar
- Ends the string if the value specified is found, default is 0
Return value
MoveToNextFileSector
Attempts to move to the next sector in the file.
When reading a file you would leave force next sector set to 0.
When writing a file you would leave force next sector set to 1 to allow new sectors to be created as the file grows.
Returns 0 for success
Parameters
- BYTE Force_Next_Sector
- 0 = Don't add new sector, 1 = Add new sector if we are at the end of the file
Return value
WriteByteToBuffer
Writes a single byte to the current 512 byte local sector buffer.
Parameters
- UINT Address
- Address Range 0 - 511
- BYTE Data
- Data Byte to write to the buffer
Return value
- This call does not return a value
AppendByteToFile
Adds a single byte to the end of the currently open file, useful for inserting the value 0 into binary file types.
Returns 0 for success.
Parameters
- BYTE Data
- Data to append to the end of the file
Return value
ReadFileSector
Overwrites local buffer with the current file sector from the disk.
Used to restore the local sector buffer with the actual sector stored on the card.
Return = 0 : Local buffer refreshed with current card sector
Return > 0 : Error
Parameters
- This macro has no parameters
Return value
ReadByteFromFile
Reads a byte from the currently open file. Auto increments the position in the file.
A return value of 0 may signify the end of the file has been reached (depending on the contents of the file).
Parameters
- This macro has no parameters
Return value
DeleteFile
Searches for and deletes a file in the current folder location on the card. Default = Root
Returns 0 for success.
Parameters
- <- STRING Filename
- 8.3 format filename e.g."file.txt"
- This parameter may be returned back to the caller
Return value
ReadByteFromIndex
Reads an arbitrary byte of data from the current open file.
Return = Data byte read from the local sector buffer.
Experimental and potentially slow if navigating backwards through the file.
Parameters
- ULONG Address
- Contains the position of the byte to be read from the file
Return value
CreateFile
Creates a file in the current folder location on the card. Default = Root
Returns 0 for success
File must be opened using "Open_File" after creation before writing any data.
Parameters
- <- STRING Filename
- 8.3 format filename e.g."file.txt"
- This parameter may be returned back to the caller
Return value
ScanCurrentFolder
Method for retreiving file or folder names for the card to allow for dynamic file opening or playback. Does not currently simulate.
0 - Filetype found and stored into string array, 1 - End of folder reached, 2 - Filetype mismatch 3 - Empty
Parameters
- UINT Current_Idx
- Contains the current pointer in the directory table. Values from 0 to 511 to completley search the current folder for a files or folders
- BYTE Scan_Type
- Sets the scan to search for Files or Folders. 0 = Scan for files, 1 = Scan for folders
Return value
ReadByteFromScan
Returns a byte of the name of the file or folder retreived from the Scan_Current_folder function.
Return = ASCII byte at position Idx from the folder name or file name at position Current_Idx in the directory
Parameters
- BYTE idx
- 0 - 11 for a file, 0 - 7 for a folder
Return value
OpenFolder
".." - Jumps up a directory, if at root then remains in root
"root" - Jumps directly back to the root directory
"foldername" - Opens folder named foldername
Parameters
- <- STRING Folder_Name
- This parameter may be returned back to the caller
Return value
ReadByteFromBuffer
Reads a byte of data from the local sector buffer.
Return = Data byte read from the local sector buffer.
Parameters
- UINT Address
- 0 - 511 - Contains the position of the byte to be read
Return value
ReadFileLength
Returns the number of bytes in the current sector that are used by the current open file.
Return = 512 - Sector is filled with file data
Return < 512 - Last sector of the file, Retval specifies how many bytes of data are remaining in the sector
Parameters
- This macro has no parameters
Return value
OpenFile
Searches for and opens a file for reading or writing from within the current directory on the disk.
Returns 0 for success.
Parameters
- <- STRING Filename
- 8.3 filename of the file we are trying to open e.g. "file.txt"
- This parameter may be returned back to the caller
Return value
WriteFileSector
Overwrites the current sector on the memory card with the contents of the local sector buffer. See write_byte_to_buffer function.
Return = 0 - File sector written successfully.
Return > 0 - File sector write error
Parameters
- This macro has no parameters
Return value
SetFileIndex
Sets the current file index and used to switch between several open file streams.
Default = 0.
Parameters
- BYTE File_Index
- File index ranges from 0 to (Max Concurrent Files - 1)
Return value
- This call does not return a value
AppendStringToFile
Adds the contents of the data string parameter to the end of the currently open file.
Returns 0 for success.
Parameters
- <- STRING Data_String
- Data to append to the end of the file
- This parameter may be returned back to the caller
Return value
ReadFileSize
Reads the entire size of the current file in bytes.
Parameters
- This macro has no parameters
Return value
SetTimeAndDate
Sets the current time and date.
Time = (Hour << 11) + (Min << 5) + (Sec >> 1)
Date = (YearFrom1980 << 9) + (Month << 5) + (Day)
Additional details can be found here: http://www.maverick-os.dk/FileSystemFormats/FAT16_FileSystem.html#TimeFormat
Parameters
- UINT Time
- Sets the current Time in FAT Time format hhhhhmmmmmmsssss - S=Secs/2
- UINT Date
- Sets the current Date in FAT Date format yyyyyyymmmmddddd - Y=Years since 1980
Return value
- This call does not return a value
Initialise
Attempts to communicate with the SD card and if successful sets up the file system.
Returns 0 for success.
Parameters
- This macro has no parameters
Return value
Simulation macro reference
This component does not contain any simulation macros
Property reference
Max Concurrent Files
This property is of type Unsigned integer and can be referenced with the variable name max_concurrent_files.
Specifies how many concurrent files can be opened at any one time.
Use the SetFileIndex macro to switch between concurrent files.
End Of File
This property is of type Fixed list of ints and can be referenced with the variable name EOFtype.
Specifies the way the ReadByteFromFile function indicates the end of a file.
8 Bit mode - End of the file is represented by the value 0, read multiple times to confirm that the 0 is not simply data.
16 Bit mode - End of file is represented by the value 512 allowing the values 0 - 255 to represent valid data.
Root Directory
This property is of type Directory and can be referenced with the variable name root_dir.
Directory flagged as root for simulation Default: $(srcdir) is the current project source directory.
Modern windows systems do not like you writing files to a hard drive root directory so a directory off the root is advised.
