FC_GetFreeDiskSpace - General Information

Overview

Type:

Function

Available as of:

SystemInterface_1.34.1.0

Support for:

-

Versions:

Current version

Task

Read out the free memory space of a memory medium.

Description

This function reads out the free memory space of a memory medium (flash disk, RAM disk, USB device) in bytes. The name of the memory medium is transferred:

  • Flash disk = "ide0:"

  • RAM disk = "ram0:"

  • USB device = "/usb2msd16a"

The free memory space of a remote device cannot be read out. If a remote device is specified as parameter, then the function returns "-1".

Interface

Input

Data type

Description

i_sVolumeName

STRING[80]

Name of the device whose free memory space shall be read out

Input/Output

Data type

Description

iq_uliFreeDiskSpace

ULINT

Free memory space in byte

Return Value

Data type

Description

DINT

0: Free memory space was read out successfully

-1: Error when reading out the free memory, for example, an invalid device or remote device was selected

-318: Invalid parameter (i_sVolumeName)

Example

Requirement

The free memory space on a USB device has to be determined. For this, the USB device has to be detected successfully.

Declaration 

PROGRAM FreeUSBDiskSpace
VAR
   uliFreeDiskSpace : ULINT := 0;
   diStatus : DINT := 0;
   diBytesOfMegaByte : DINT := 1048576; // = 1024 * 1024
   diFreeDiskSpaceInMB : LINT := 0;
END_VAR

Program 

diStatus := FC_GetFreeDiskSpace ( '/usb2msd16a', uliFreeDiskSpace );
IF (diStatus = 0) THEN
   diFreeDiskSpaceInMB := ULINT_TO_LINT(uliFreeDiskSpace) / diBytesOfMegaByte;
END_IF

Result

diFreeDiskSpaceInMB contains the free memory space of the USB memory medium in Mb.