Plc programming – Lenze ETC Motion Control User Manual

Page 385

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PLC programming

Library

FILE IO functions

8

8.8

8.8.3

l

385

EDSTCXN EN 2.0

8.8.3.5

SYSCLOSEFILE

FUNCTION SYSCLOSEFILE: DINT

VAR_INPUT

handle_di

: DINT;

END_VAR

The function is used to close a file previously opened with SysOpenFile(). The
content of the FLASHPROMs is only updated in the FLASHPROM after the last
file opened for write−access has been closed. The return value of the function
is less than 0 for an error (all error codes are defined in the global constants
of the library).

handle_di

File handle (returned by SysOpenFile())

8.8.3.6

SYSREADFILE

FUNCTION SYSREADFILE: DINT

VAR_INPUT

handle_di

: DINT;

(* File handle returned by SysOpenFile *)

buffer_p

: DINT;

(* Address of a buffer where the data are stored *)

maxlen_di

: DINT;

(* Buffer length in byte *)

END_VAR

The function is used for reading blocks (in sequence) from a file previously
opened with SysOpenFile(). A maximum of maxlen_di characters are read
from the file into the buffer defined with buffer_p. Less than maxlen_di
characters will only be read if the file end is reached before or a read error
occurs.

Return value: Actual number of read characters; 0 for file end or less than 0
for error (

391).

handle_di

: DINT;

num_di

: DINT;

ret_di

: DINT;

buffer_from

: ARRAY[0..100] OF BYTE;

handle_di

:= SYSOPENFILE(’test.dat’, O_RDONLY);

num_di

:= SYSREADFILE(handle_di, ADR(buffer_from), 20);

ret_di

:= SYSCLOSEFILE(handle_di);

Declaration

Description

Parameters

Declaration

Description

Example

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