FileExists

Description

This function block tests if a file exists.

Figure 7-206: The FileExists Function Block

Related Functions

FileCopy, FileDelete, FileRename, FileSize

See also: File Management

Arguments

Input

Execute	Description	On the rising edge A rising edge is the transition of a digital signal from low to high. It is also called positive edge test to see if a file exists
	Data Type	BOOL
	Range	0, 1
	Unit	N/A
	Default	—
Path	Description	The path to the file
	Data Type	STRING
	Range	N/A
	Unit	N/A
	Default	—

Output

Done	Description	If TRUE, then the command completed successfully
	Data Type	BOOL
Error	Description	If TRUE, an error has occurred
	Data Type	BOOL
ErrorID	Description	Indicates the error if Error output is set to TRUE. See the table in Search IndexFile and TCP/IP Function Block ErrorID Output
	Data Type	DINT
Exists	Description	The existence of the file. True: this value indicates the file exists False: this value indicates the file does not exist.
	Data Type	BOOL

Example

Structured Text

(* FileExists example *)
CASE StepCounter OF
0:
   Inst_FileExists(TRUE, 'Test.txt');
   StepCounter := StepCounter + 1;
1:
   Inst_FileExists(TRUE, 'Test.txt');
   IF Inst_FileExists.Done THEN
      TestFileExists := Inst_FileExists.Exists;
      Inst_FileExists(FALSE, '');
      StepCounter := StepCounter + 1;
   END_IF;
END_CASE;