File Management

File Management functions provide the ability to:

• Read machine recipes or other machine operational data into the KAS program from the SD card, USB "Universal Serial Bus" USB is a serial bus standard to interface devices flash drive, or a shared directory.
• Read cam tables into the program from the SD card, USB flash drive, or a shared directory.
• Store machine operational data in internal PxMM or PCMM2G flash memory (retrievable through the web server), the SD card, USB flash drive, or a shared directory.

• 
  A shared directory connection is setup through the web server.

• 
  
• • Functions to parse out information from a file using a string format can be found in String Operations.
  • If the file is in a .CSV format, these functions can be used: LogFileCSV, ApplyRecipeColumn.
  • You can create, store, and retrieve recipes and other data using either:
    • the AKI Terminals. For more information see the KVB manual.
    • an external bus connection to the PxMM or PCMM2G with a supported fieldbus (e.g., UDP or HTTP).

These function blocks enable sequential read / write operations in disk files:

Fucnction Block	Use
FileClose	Close an open file.
FileCopy	Copy a file.
FileDelete	Remove a file.
FileEOF	Test if the end of the file is reached in a file that is open for reading.
FileExists	Test if a file exists.
FileOpenA	Create or open a file in append mode.
FileOpenR	Open a file for reading.
FileOpenW	Create or reset a file and open it for writing.
FileReadBinData	Read binary data from a file.
FileReadLine	Read a string value from a text file.
FileRename	Rename a file.
FileSeek	Set the current position of a file.
FileSize	Get the size of a file.
FileWriteBinData	Write binary data to a file.
FileWriteLine	Write a string value to a text file.

These functions handle mounting of SD cards:

Name	Use
SD_ISREADY	Check that the SD card is ready for read/write
SD_MOUNT	Mount an SD card
SD_UNMOUNT	Unmount an SD card

Each file is identified in the application by a unique handle manipulated as a DINT value.

• The file handles are allocated by the target system.
• Handles are returned by the Open function blocks and used by all other function blocks for identifying the file.

Related Function A function calculates a result according to the current value of its inputs. A function has no internal data and is not linked to declared instances. Blocks

LogFileCSV log values of variables to a CSV file

• 
  

• • Files are opened and closed directly by the Operating System of the target.
    • Opening some files can be dangerous for system safety and integrity.
    • The number of open files (from FileOpenA, FileOpenR, and FileOpenW) is limited by the resources available on the target system.
  • Ensure that each file successfully opened using FileOpenA, FileOpenR, and FileOpenW.
    • The FileOpenW has a corresponding FileClose to close the file.
    • Closing the file will release the file ID, making it available for operations on other files.

• 
  

• • Opening a file with FileOpenA, FileOpenR, and FileOpenW can be unsuccessful (invalid path or file name, too many open files.)
    • Your application must check the file ID for a NULL value.
    • If the file ID is NULL (zero), then file read or write operations will fail.
  • File management may be unavailable on some targets.
  • Memory on the SD card is available in addition to the existing flash memory.
  • Valid paths for storing files depend on the target implementation.
  • Error messages are logged in the Controller log section of KAS Runtime In computer science, runtime (or run-time) describes the operation of a computer program, the duration of its execution, from beginning to termination (compare compile time). Within KAS, runtime also refers to the virtual machine that manage the program written in a computer language while it is running where there is a failure in any related function block.
  • Using the KAS Simulator, all path names are ignored, and files are stored in a reserved directory. Only the file name passed to the Open functions is taken into account.
    
  • AKD PDMM / PCMM files are big endian.
    • PCMM2G files are little endian.

• 
  
• Review the File Path Conventions to understand hardware-based functional differences.