FB_AsciiReader

FB_AsciiReader - General Information

Overview

Type:	Function block
Available as of:	V1.7.0.0
Inherits from:	-
Implements:	-
Versions:	Current version

Task

Reading a variables table from a file

Description

NOTE: The function block FB_AsciiReader only works correctly if the used data structures are saved with Pack_Mode = 1.

The function reads the number of variables of the type specified in i_pbyStructInfo which is indicated in i_iCount from a text file into the memory at the address specified in i_dwBufferAdr.

Reading is started with a positive edge at i_xExecute and stopped after an error is detected or after all data has been read successfully. During reading, no parameter (other than i_xExecute) may be changed. Also, that memory area which i_dwBufferAdr points to may not be written to.

The file first has to be created with FB_AsciiWriter or any other editor and has to have the following format:

oOptional header with maximum 10 lines with, for example, comments, variable names, column headers, and so on. See also inputs i_xStructNames and i_uiLinesOfHeader.

oEach further line must contain a value for all variables of the structure in the respective format.

oThe individual values should be separated by tabs and each end of line marked by CRLF.

Interface

Input	Data type	Description
i_xExecute	BOOL	FALSE -> TRUE: POU is activated. The reading process begins.
i_sFileName	STRING	Name of the text file where the variable should be read from.
i_iCount	INT	Maximum number of records that should be read.
i_dwBufferAdr	DWORD	Address of the array where the data should be stored. The respective amount of memory must be reserved. a: ARRAY [0..i_iCount-1] OF Struct BufferAdr:=adr(a);
i_pbyStructInfo	POINTER TO BYTE	Start address of the string with the description of a record in the structure. The standard type of the individual variables are separated by a comma. e.g. 'BOOL,DWORD,USINT'
i_xStructNames	BOOL	TRUE: The number of lines defined by i_uiLinesOfHeader in the file will be disregarded. This is required if the file was created with HYPERLINK "54043196593213067.html"FB_AsciiWriter and, in addition to the data, variable names were saved or if the file was created with Excel and the column headers were also saved.
i_uiLinesOfHeader	BOOL	Number of lines at the beginning of the file which will be disregarded if i_xStructNames = TRUE. Default value = 1 Range = 1...10

Output	Data type	Description
q_xBusy	BOOL	TRUE: Reading is in progress.
q_xDone	BOOL	Reading is completed.
q_etDiag	GD.ET_Diag	General library-independent statement on the diagnostic. A value not equal to ET_Diag.Ok corresponds to an diagnostic message.
q_etDiagExt	ET_DiagExt	POU-specific output on the diagnostic. q_etDiag = ET_Diag.Ok -> Status message q_etDiag <> ET_Diag.Ok -> Diagnostic message
q_sMsg	STRING[80]	Event-triggered message which gives more detailed information on the diagnostic state.
q_udiUsedMemory	UDINT	Number of written bytes in the memory.
q_udiUsedDiskSpace	UDINT	Number of bytes read out of the file.

Example

{attribute 'pack_mode' := '1'}
TYPE ST_MyType :
STRUCT
sName : STRING[30];sStreet : STRING[20];
lrValue : LREAL;
END_STRUCT
END_TYPE

VAR
fbAsciiReader : FB_AsciiReader;
aMyType : ARRAY[0..99] OF ST_MyType;
END_VAR

fbAsciiReader(i_xExecute := TRUE,
i_sFileName := 'Data',
i_iCount := 100,
i_dwBufferAdr := ADR(aMyType),
i_pbyStructInfo := 'STRING[30], STRING[20], LREAL',
i_xStructNames := TRUE),
i_uiLinesOfHeader := 1);

Diagnostic Messages

q_etDiag	q_etDiagExt	Enumeration value	Description
OK	Executing	128	Version
OK	WaitForExecute	180	Wait for execution.
FileHandlingInvalid	FileNotExisting	104	The file does not exist.
FileHandlingInvalid	FileReadingInvalid	106	Error detected when reading from file.
FileHandlingInvalid	TooManyFilesOpen	105	Too many files are opened.
InputParameterInvalid	StructInfoInvalid	40	The StructInfo is invalid.
InputParameterInvalid	InvalidInputValue	324	The input value is outside the valid range.
UnexpectedProgramBehavior	UnexpectedFeedback	1	An unintended detected error occurred during execution.

Executing

Enumeration name:	Executing
Enumeration value:	128
Description:	Version

The data is being read.

FileNotExisting

Enumeration name:	FileNotExisting
Enumeration value:	104
Description:	The file does not exist.

Issue	Cause	Solution
-	The file does not exist.	Copy the file to the flash disk of the controller.
-	At the input i_sFilename, a file name has been applied that does not exist.	Verify the file name at i_sFilename.

FileReadingInvalid

Enumeration name:	FileReadingInvalid
Enumeration value:	106
Description:	Error detected when reading from file.

Issue	Cause	Solution
-	The file is damaged.	Create the file again.

InvalidInputValue

Enumeration name:	InvalidInputValue
Enumeration value:	324
Description:	The input value is outside the valid range.

Issue	Cause	Solution
-	The value of i_uiLinesOfHeader is invalid.	Verify that the value for i_uiLinesOfHeader is in a range of 1…10.

StructInfoInvalid

Enumeration name:	StructInfoInvalid
Enumeration value:	40
Description:	The StructInfo is invalid.

Issue	Cause	Solution
-	At the memory address which the input i_pbyStructInfo points to, no valid structure data are applied.	Verify the data of the string that is transferred via the pointer. Verify the address that is transferred at the input i_pbyStructInfo.

Issue

Cause

Solution

At the memory address which the input i_pbyStructInfo points to, no valid structure data are applied.

Verify the data of the string that is transferred via the pointer.

Verify the address that is transferred at the input i_pbyStructInfo.

TooManyFilesOpen

Enumeration name:	TooManyFilesOpen
Enumeration value:	105
Description:	Too many files are opened.

Issue	Cause	Solution
-	Too many files are opened.	Close files that are no longer needed using SystemInterface.FC_CloseFile.

UnexpectedFeedback

Enumeration name:	UnexpectedFeedback
Enumeration value:	1
Description:	An unintended detected error occurred during execution.

Issue	Cause	Solution
-	An error occurred in the internal execution.	An error occurred in the internal execution.

WaitForExecute

Enumeration name:	WaitForExecute
Enumeration value:	180
Description:	Wait for execution.

The function block is ready. As reaction to a positive edge from i_xExecute, the data are read out.