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 7-210: 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;