Delete XLS Files Using VBScript in Siemens WinCC HMI Runtime

Delete XLS Files Using VBScript in Siemens WinCC HMI Runtime

Overview

Siemens WinCC Runtime environments (WinCC Flexible 2008, WinCC Comfort/Advanced in TIA Portal V13 through V19) execute VBScript inside the HMI panel's runtime, where standard Windows file APIs are not directly available. To delete generated .xls, .csv, or .txt files from a panel's storage card, the script must use either the Siemens-supplied FileCtl.Filesystem COM object (the supported runtime API) or the standard Scripting.FileSystemObject (available on PC-based WinCC Runtime only). This reference shows the working pattern, the correct path conventions for a Siemens TP/Comfort Panel storage card, and the error-handling block required for production deployment.

The procedure below is engineered for a weld-results use case where the panel writes a series of .xls reports to \Storage Card SD\Weld_Results\ and a cleanup routine must purge the directory after data is archived. The same pattern applies to recipe exports, alarm logs, batch reports, and audit trails.

Prerequisites

1. WinCC project configuration: TIA Portal V13 SP1 or later (V16/V17/V18/V19 recommended for current firmware), with a Comfort Panel (TP700/TP900/TP1200/TP1500/TP1900) or a WinCC Runtime Advanced PC target.
2. Storage medium: An SD card or USB stick formatted as FAT32, mounted on the panel. Internal flash and the \Storage Card SD\ path require the media to be present at boot.
3. Runtime scripting enabled: In TIA Portal, open the HMI device → Properties → Runtime settings → Services. Enable VB scripting and confirm the script DLLs are deployed.
4. User rights: The user logged in on the panel must have permission to write to the target directory. Configure the user administration under → "User administration" with at least Operator rights for the storage card path.
5. Tag list: The SmartTags referenced in the cleanup script must be defined as HMI tags of the correct data type (Word, Int, Bool) before the script is executed.

WinCC VBScript File System Objects

Two COM objects are available for file-system work in WinCC Runtime VBScript. They are not interchangeable, and selecting the wrong one is the most common cause of the "Object doesn't support this property or method" runtime alarm on a panel.

Microsoft VBScript Reference

The Delete method example (VBScript) on Microsoft Learn documents the canonical FileSystemObject.DeleteFile call against a hard-coded path. The pattern is identical to what is used inside WinCC PC Runtime:

Dim fso, FileToDelete
Set fso = CreateObject("Scripting.FileSystemObject")
FileToDelete = "c:\asdflkasd.xls"
fso.DeleteFile(FileToDelete)

On a Siemens panel this exact pattern returns error 429 because scrrun.dll is not registered in the panel runtime image. Use FileCtl on panels and Scripting.FileSystemObject on PC Runtime targets.

Path Conventions for Siemens Panels

The path string passed to FileCtl must follow the storage-card convention used by the panel's Windows CE / Windows Embedded Compact runtime:

Step-by-Step: Building the Delete Routine

Step 1 - Define the HMI tag interface

Create the SmartTags that the cleanup script will read and reset. All tags are HMI tags of type Word unless noted.

Step 2 - Build the enumeration phase

The first FileCtl.Filesystem instance is used to walk the directory with Dir. Each call returns the next matching filename; the loop continues until an empty string is returned.

Dim fs, cleanPath, file, strTemp, total, f, strTemp1, fso

'--- Enumeration: count files in target directory ---
Set fs = CreateObject("FileCtl.Filesystem")
SmartTags("WR_fileCount") = 0

strTemp = fs.Dir("\Storage Card SD\Weld_Results\" & "*.*")
While (Len(strTemp) > 0)
    SmartTags("WR_fileCount") = SmartTags("WR_fileCount") + 1
    strTemp = fs.Dir()    'no argument returns the next file
Wend

Step 3 - Execute the delete phase

A second FileCtl.Filesystem instance is created to call Kill with a wildcard. Reusing the same object after Dir resets its internal cursor; using two instances is cleaner and avoids the subtle "file 1 deleted but file 2 is the one I started with" off-by-one bug seen in field deployments.

Set fs = Nothing
Set fso = CreateObject("FileCtl.Filesystem")

strTemp1 = fso.Dir("\Storage Card SD\Weld_Results\*.*", 0)
fso.Kill("\Storage Card SD\Weld_Results\*.*")

Step 4 - Handle runtime errors

Kill raises VBScript errors that must be caught with On Error Resume Next and a manual Err.Number check. The WinCC function ShowSystemAlarm queues the message into the panel's alarm buffer for display in the alarm view.

If Err.Number <> 0 Then
    ShowSystemAlarm "Error#" & CStr(Err.Number) & " " & Err.Description
    Err.Clear
    Exit Sub
End If

Step 5 - Reset tag pointers and repaint the screen

After deletion, the on-screen table is stale. Reset the index tags and call the helper WR_Screen_Zero_Clear to repaint the table with zero rows.

SmartTags("WR_Files_present") = 0
SmartTags("WR_Linecount") = 0
SmartTags("WR_Total_pages") = 1
SmartTags("WR_Page_counter") = 1
SmartTags("WR_Page_Current") = 1
SmartTags("WR_Screen_arrow_dn_visible") = 0
SmartTags("WR_Screen_arrow_up_visible") = 0
SmartTags("WR_File_present") = 0
SmartTags("WR_Zero_ed") = 0

WR_Screen_Zero_Clear

If Err.Number <> 0 Then
    ShowSystemAlarm "Error#" & CStr(Err.Number) & " " & Err.Description
    Err.Clear
End If

Complete Working Script

Assemble the steps into a single subroutine and bind it to a button's "Click" event in the WinCC screen layout.

Sub WR_Delete_Files()
    On Error Resume Next
    Dim fs, cleanPath, file, strTemp, total, f, strTemp1, fso

    '--- Enumerate and count ---
    Set fs = CreateObject("FileCtl.Filesystem")
    SmartTags("WR_fileCount") = 0
    strTemp = fs.Dir("\Storage Card SD\Weld_Results\" & "*.*")
    While (Len(strTemp) > 0)
        SmartTags("WR_fileCount") = SmartTags("WR_fileCount") + 1
        strTemp = fs.Dir()
    Wend
    Set fs = Nothing

    '--- Delete all files in folder ---
    Set fso = CreateObject("FileCtl.Filesystem")
    strTemp1 = fso.Dir("\Storage Card SD\Weld_Results\*.*", 0)
    fso.Kill("\Storage Card SD\Weld_Results\*.*")

    If Err.Number <> 0 Then
        ShowSystemAlarm "Error#" & CStr(Err.Number) & " " & Err.Description
        Err.Clear
        Exit Sub
    End If

    '--- Reset pointers ---
    SmartTags("WR_Files_present") = 0
    SmartTags("WR_Linecount") = 0
    SmartTags("WR_Total_pages") = 1
    SmartTags("WR_Page_counter") = 1
    SmartTags("WR_Page_Current") = 1
    SmartTags("WR_Screen_arrow_dn_visible") = 0
    SmartTags("WR_Screen_arrow_up_visible") = 0
    SmartTags("WR_File_present") = 0
    SmartTags("WR_Zero_ed") = 0

    '--- Repaint table ---
    WR_Screen_Zero_Clear

    If Err.Number <> 0 Then
        ShowSystemAlarm "Error#" & CStr(Err.Number) & " " & Err.Description
        Err.Clear
    End If
End Sub

Verification Procedure

1. Compile check: In TIA Portal, compile the HMI project. Any syntax error in the VBScript raises a red entry under → "Scripts" with the offending line.
2. Simulator run: Start WinCC Runtime Advanced simulator, populate \Storage Card SD\Weld_Results\ with one or more .xls files, click the button bound to WR_Delete_Files. Confirm the files are removed and WR_fileCount drops to zero.
3. On-panel run: Transfer the compiled project to the panel, repeat the test with a real SD card. Confirm the storage card is still readable in Windows after the panel is rebooted.
4. Empty-folder run: Trigger the routine on an empty directory. Expect zero files enumerated, zero errors, and WR_fileCount = 0.
5. Error path: Mark one .xls read-only on the SD card from a PC, lock the SD card write-protect tab, or remove the SD card before the script runs. The error branch must fire ShowSystemAlarm with the correct VBScript error number.

Error Codes and Diagnostics

Troubleshooting Matrix

Safety and Operational Notes

For audit-traceable systems, write a log line to a separate .csv file in \Storage Card SD\Audit\ before calling Kill:

fso.WriteLine "DELETE," & Now() & "," & SmartTags("WR_fileCount") & " files"

This same write can be performed with FileCtl.OpenTextFile on a panel runtime, mirroring the standard VBScript OpenTextFile / WriteLine pattern.

Cross-Platform Variant: PC Runtime (WinCC Runtime Advanced)

When the target is a Windows-based WinCC Runtime Advanced (PC station), switch to the standard Scripting.FileSystemObject to gain access to DeleteFile with attribute control, FSO folder enumeration, and Unicode paths.

Sub PC_Delete_Results()
    On Error Resume Next
    Dim fso, folder, files, file
    Set fso = CreateObject("Scripting.FileSystemObject")
    Set folder = fso.GetFolder("C:\Weld_Results")
    Set files = folder.Files
    For Each file In files
        If LCase(fso.GetExtensionName(file.Name)) = "xls" Then
            file.Delete True   'force delete even if read-only
        End If
    Next
    If Err.Number <> 0 Then
        ShowSystemAlarm "Error#" & CStr(Err.Number) & " " & Err.Description
        Err.Clear
    End If
    Set fso = Nothing
End Sub

The True argument to file.Delete forces removal of read-only files, which is not available from the panel-side FileCtl.Kill. Use this variant on PC Runtime only.

FAQ