Functional description

The safety-related SF_RecipeDeleteFile function block is part of a safety library which provides function blocks for the applicative recipe handling of the Safety PLC.

The SF_RecipeDeleteFile FB can delete a specified recipe file from the remanent flash memory (e.g., SD card) of the higher-level standard controller. This file has been created using the SF_RecipeWrite function block.

After completing the file delete operation, the Done output is set to SAFETRUE.

Note
The library also provides the SF_RecipeDeleteDataSet FB which can delete specific data sets within a recipe file.

Recognition of incorrect/invalid file ID

The function block implements measures to detect if an invalid file ID is applied to the FB input, or if the file to be deleted does not exist.

Allowed but potentially unwanted multiple accesses

Other simultaneous accesses by several recipe function blocks may be not considered as an error but should nevertheless either be prevented by structuring the safety application accordingly or, if they are necessary, verified carefully by means of a function test.
Examples for such generally allowed but potentially critical simultaneous accesses are:

Simultaneous read and "file delete" operations within one cycle.
Simultaneous write and "file delete" operations within one cycle.
Multiple delete requests for the same file by several instances of the SF_RecipeDeleteFile function block are possible: The file is deleted and each instance reports success.

Further Info
Refer to the help topic "Fault avoidance" for further details.