FB_FileWrite

FB_FileWrite 1:

The function block writes data into a file. For write access the file must have been opened in the corresponding mode, and it must be closed again for further processing by external programs.

FB_FileWrite 2: Inputs

VAR_INPUT
    sNetId     : T_AmsNetId;
    hFile      : UINT;
    pWriteBuff : PVOID;
    cbWriteLen : UDINT;
    bExecute   : BOOL;
    tTimeout   : TIME := DEFAULT_ADS_TIMEOUT;
END_VAR

Name

Type

Description

sNetId

T_AmsNetId

String containing the AMS network ID of the target device to which the ADS command is addressed (type: T_AmsNetId).

hFile

UINT

File handle, which was generated when the function block FB_FileOpen was created.

pWriteBuff

PVOID

Address of the buffer containing the data to be written. The buffer can be a single variable, an array or a structure, whose address can be found with the ADR operator.

cbWriteLen

UDINT

Number of bytes to be written

bExecute

BOOL

The function block is activated by a rising edge at this input.

tTimeout

TIME

States the length of the timeout that may not be exceeded by execution of the ADS command.

FB_FileWrite 3: Outputs

VAR_OUTPUT
    bBusy    : BOOL;
    bError   : BOOL;
    nErrId   : UDINT;
    cbWrite  : UDINT;
END_VAR

Name

Type

Description

bBusy

BOOL

When the function block is activated, this output is set to TRUE and remains set until feedback is received. As long as bBusy is TRUE, no new command can be executed.

bError

BOOL

If an error occurs during command execution, this output is set, once the bBusy output has been reset.

nErrId

UDINT

Returns the ADS error code or the command-specific error code when the bError output is set.

cbWrite

UDINT

Contains the number of the last successfully written data bytes. A write error indicates that the number of successfully written data bytes is less than the requested length (cbWriteLen) or zero. A write error can occur if the data carrier is full, for example. If a write error occurs, the bError and nErrID outputs are not set. Since the PLC application knows the number of data bytes to be written, it can compare the actual written length with the requested length and detect write errors. When a write error occurs, the internal file pointer has an undefined position.

Command-specific error code

Possible cause

0x703

Invalid or unknown file handle.

0x70E

File was opened with wrong method (e.g. with obsolete FILEOPEN function block).

Example of calling the block in ST:

Example of calling the block in FBD:

PROGRAM Test
VAR
    fbFileWrite      : FB_FileWrite;
    hFile            : UINT;
    bFileWrite       : BOOL;
    bFileWriteBusy   : BOOL;
    bFileWriteError  : BOOL;
    nFileWriteErrorId: UDINT;
    nFileWriteCount  : UDINT;
    fileData         : ARRAY[0..9] OF BYTE;
END_VAR
FB_FileWrite 4:

In the example, after a rising edge at bFileWrite, 10 bytes of the array FILEDATA are written to the file.

Requirements

Development environment

Target system type

PLC libraries to include (Category group)

TwinCAT v3.1.0

PC or CX (x86, x64, ARM)

Tc2_System (System)