FileReadLine

Description

This function block reads a string value from a file. FileReadLine stops reading from the file if 255 characters are read (the maximum length of the STRING type) or if a new line is encountered.

Figure 7-201: The FileReadLine Function Block

Related Functions

FileClose, FileEOF, FileOpenA, FileOpenR, FileOpenW, FileReadBinData, FileSeek, FileWriteBinData, FileWriteLine

See also: File Management

Arguments

Input

Execute	Description	On the rising edgeA rising edge is the transition of a digital signal from low to high. It is also called positive edge read the size of a file.
	Data Type	BOOL
	Range	0, 1
	Unit	N/A
	Default	—
ID	Description	ID of the open file.
	Data Type	UDINT
	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
Value	Description	The string value read from the file.
	Data Type	STRING

Example

Structured Text

(* FileReadLine example *)
CASE StepCounter OF
0:
   Inst_FileReadLine(TRUE, MyInputFileID);
   StepCounter := StepCounter + 1;
1:
   Inst_FileReadLine(TRUE, MyInputFileID);
   IF Inst_FileReadLine.Done THEN
      lineText := Inst_FileReadLine.Value;
      Inst_FileReadLine(FALSE, 0);
      StepCounter := StepCounter + 1;
   END_IF;
END_CASE;