Loading INI and CSV Files at WinCC Runtime Startup: TIA V13

Runtime Identification: Professional vs Advanced vs Panel

Before any VBScript is written, confirm which TIA Portal WinCC edition is in scope. The WinCC VBS programming model is shared across the WinCC family, but the tag-access syntax, file-system permissions, and storage locations differ in ways that will silently break a script that was authored for the wrong edition.

If the project is loaded on a PC with a true C: drive, the Runtime is almost certainly WinCC Professional (or RT Advanced on PC). Scripts written for a SIMATIC Panel must be retargeted because the file-system root, the trailing slash conventions, and the COM-object availability all change.

The two Siemens FAQ articles that anchor this topic are:

• Siemens FAQ 850338 - File access with VBS in WinCC V7.x / Professional
• Siemens FAQ 106501825 - File access with VBS on SIMATIC WinCC Panels / RT Advanced

The script syntax in FAQ 850338 is written for WinCC V7.2 but the same COM objects, the same Scripting.FileSystemObject calls, and the same SmartTags access pattern carry forward into WinCC Professional V13, V14, V15, V16, V17 and V18 unchanged. Newer TIA Portal versions add helpers but the V7.2-era code still runs.

Prerequisites

1. TIA Portal V13 SP1 Update 9 (or any later V13.x) with WinCC Professional installed and licensed. The Professional option must be active - it is a separate license on top of TIA Portal.
2. WinCC RT Professional license on the Runtime PC, either a USB hardlock or a software key in C:\Program Files (x86)\Siemens\Automation\SimaticLicenseManager.
3. Windows user account that starts the WinCC Runtime service with read access to the target file. On a default install, the Runtime service starts under SIMATIC HMI user; that user must be granted Read on the directory containing the .ini or .csv file.
4. HMI tags already declared in the project for every value the script will write. VBS cannot create tags at runtime; missing tags raise Smart Tags errors in the WinCC diagnostics window and the value is silently dropped.
5. A startup event scheduled in the project scheduler that fires before any operator screen reads the tag. See the Wiring the Script to Runtime Startup section below.

VBScript File Access Model in WinCC

WinCC Runtime exposes the standard Windows Script Host (WSH) object model. Two COM objects cover almost every file-handling use case:

A minimal reading pattern:

Dim oFSO, oFile, sLine
Set oFSO = CreateObject("Scripting.FileSystemObject")
If oFSO.FileExists("C:\Recipes\Config.ini") Then
    Set oFile = oFSO.OpenTextFile("C:\Recipes\Config.ini", 1, False, -1)
    Do While Not oFile.AtEndOfStream
        sLine = oFile.ReadLine
        ' parse sLine here
    Loop
    oFile.Close
End If
Set oFile = Nothing
Set oFSO = Nothing

The third argument to OpenTextFile is create-if-missing; pass False for read-only. The fourth argument is the format: -2 opens with system default encoding, -1 forces Unicode, 0 forces ASCII. For CSV files exported by Excel on a Western Windows install the safest default is -1 (Unicode), because Excel often prepends a BOM that confuses ReadLine under ASCII mode.

Reading an INI File - Procedure

An INI file is line-oriented with three line types:

• [SectionName] - header line
• Key=Value - assignment
• ; comment or blank - ignored

Step 1 - Add a project-wide VBS function

Open the project tree in TIA Portal, right-click Scripts > VBScripts, choose Add new function, and name it ReadINIValue. Paste the following implementation. It returns a default value when the key is missing, the file is missing, or the file cannot be parsed - this keeps Runtime startup robust against a missing recipe file.

Function ReadINIValue(ByVal sFile, ByVal sSection, _
                      ByVal sKey, ByVal sDefault)
    Dim sResult, sLine, bInSection, iEq
    Dim oFSO, oFile

    On Error Resume Next
    Set oFSO = CreateObject("Scripting.FileSystemObject")
    If Err.Number <> 0 Then
        ReadINIValue = sDefault
        Exit Function
    End If

    If Not oFSO.FileExists(sFile) Then
        Set oFSO = Nothing
        ReadINIValue = sDefault
        Exit Function
    End If

    Set oFile = oFSO.OpenTextFile(sFile, 1, False, -1)
    If Err.Number <> 0 Then
        Set oFSO = Nothing
        ReadINIValue = sDefault
        Exit Function
    End If

    bInSection = False
    Do While Not oFile.AtEndOfStream
        sLine = Trim(oFile.ReadLine)
        If Len(sLine) = 0 Then GoTo NextLine

        If Left(sLine, 1) = "[" And Right(sLine, 1) = "]" Then
            bInSection = (UCase(Mid(sLine, 2, Len(sLine) - 2)) = UCase(sSection))
        ElseIf bInSection And Left(sLine, 1) <> ";" Then
            iEq = InStr(1, sLine, "=", vbTextCompare)
            If iEq > 0 Then
                If Trim(Left(sLine, iEq - 1)) = sKey Then
                    sResult = Trim(Mid(sLine, iEq + 1))
                    Exit Do
                End If
            End If
        End If
NextLine:
    Loop
    oFile.Close
    Set oFile = Nothing
    Set oFSO = Nothing

    If Err.Number <> 0 Or Len(sResult) = 0 Then
        ReadINIValue = sDefault
    Else
        ReadINIValue = sResult
    End If
End Function

Step 2 - Call from a startup action

Add a second function LoadConfig that resolves the value and writes it to a tag. Casting to CInt forces the integer tag type required by the project:

Sub LoadConfig()
    Dim sVal
    sVal = ReadINIValue("C:\Recipes\Config.ini", "Runtime", "BatchSize", "100")
    SmartTags("BatchSize") = CInt(sVal)

    sVal = ReadINIValue("C:\Recipes\Config.ini", "Runtime", "LineSpeed", "0")
    SmartTags("LineSpeed") = CInt(sVal)
End Sub

Reading a CSV File - Procedure

CSV is preferred when the recipe list contains many rows or when the same data is shared with Excel, the MES layer, or another SCADA. The file format is:

TagName,Value,Comment
BatchSize,250,; primary recipe
LineSpeed,1200,; mm/s
TargetTemp,82,; degC

Step 1 - Add a CSV loader function

Sub LoadCSVTags(ByVal sFile)
    Dim oFSO, oFile, sLine, arrFields, sName, sValue
    Set oFSO = CreateObject("Scripting.FileSystemObject")

    If Not oFSO.FileExists(sFile) Then
        HMIRuntime.Trace("CSV missing: " & sFile & vbCrLf)
        Set oFSO = Nothing
        Exit Sub
    End If

    Set oFile = oFSO.OpenTextFile(sFile, 1, False, -1)

    ' skip header
    If Not oFile.AtEndOfStream Then oFile.ReadLine

    Do While Not oFile.AtEndOfStream
        sLine = oFile.ReadLine
        If Len(Trim(sLine)) = 0 Then GoTo NextRow
        If Left(Trim(sLine), 1) = ";" Then GoTo NextRow

        arrFields = Split(sLine, ",")
        If UBound(arrFields) < 1 Then GoTo NextRow

        sName  = Trim(arrFields(0))
        sValue = Trim(arrFields(1))

        Select Case sName
            Case "BatchSize"
                SmartTags("BatchSize") = CInt(sValue)
            Case "LineSpeed"
                SmartTags("LineSpeed") = CInt(sValue)
            Case "TargetTemp"
                SmartTags("TargetTemp") = CInt(sValue)
            Case Else
                HMIRuntime.Trace("Unknown tag in CSV: " & sName & vbCrLf)
        End Select
NextRow:
    Loop

    oFile.Close
    Set oFile = Nothing
    Set oFSO = Nothing
End Sub

Step 2 - Schedule the loader

Sub LoadCSVTags_Startup()
    LoadCSVTags "C:\Recipes\Startup.csv"
End Sub

If the CSV contains quoted fields or commas inside values, replace the simple Split(sLine, ",") with a state-machine tokenizer. The simplest robust pattern is a tiny function that walks character-by-character and toggles an inQuotes flag whenever it sees a ":

Function SplitCSV(ByVal sLine)
    Dim a(), n, i, ch, cur, inQ
    ReDim a(10)
    n = 0 : cur = "" : inQ = False

    For i = 1 To Len(sLine)
        ch = Mid(sLine, i, 1)
        If ch = """" Then
            inQ = Not inQ
        ElseIf ch = "," And Not inQ Then
            If n > UBound(a) Then ReDim Preserve a(n + 10)
            a(n) = cur : n = n + 1 : cur = ""
        Else
            cur = cur & ch
        End If
    Next
    If n > UBound(a) Then ReDim Preserve a(n)
    a(n) = cur : n = n + 1
    ReDim Preserve a(n - 1)
    SplitCSV = a
End Function

Wiring the Script to Runtime Startup

The Sub only fires when something calls it. Tie it to Runtime startup using the WinCC scheduler:

1. In the project tree expand Common data > Schedulers.
2. Open Schedulers and add a new task. Set Trigger to Runtime start.
3. Set Function list or Event to call LoadConfig (INI) or LoadCSVTags_Startup (CSV).
4. Compile and download the project. Confirm the new task appears in the Runtime under System info > Schedulers.

Alternative: assign the function to a screen's Open event on the start screen if a single screen handles the load. This is less robust because if the operator changes start screens later the script is bypassed.

Differences for Advanced Runtime and Panels

The same VBS skeleton works, but several behaviors diverge. The table summarizes what changes when the same project is ported from a PC Runtime to a Comfort/MTP panel.

For panel targets the script body stays the same but the path constants change:

Sub LoadCSVTags_Panel()
    LoadCSVTags "\Storage Card2\Recipes\Startup.csv"
End Sub

Siemens FAQ 106501825 documents the panel-specific file-system restrictions and gives a working snippet that uses HMIRuntime.FileSystem instead of raw Scripting.FileSystemObject when an OEM wants path validation.

File Path Conventions and Whitelisting

Modern TIA Portal versions (V15 and later, back-ported to V13 SP1 Update 9 through a hotfix) restrict script access to a configurable allow-list to limit damage from malicious RT files. The whitelist lives in the project's RT properties:

1. Open Runtime settings > Services > Scripting.
2. Add the absolute path C:\Recipes\ to the allowed directories.
3. If the path is not allow-listed, OpenTextFile returns error 70 - Permission denied even though the Windows ACL permits the read.

For multi-machine deployments where the file is served from a UNC share, the path must be entered as \\Server\Share\Recipes\. The Runtime service account must also have a Kerberos or NTLM trust to that share; otherwise the error shifts from 70 to 462 - remote server not found or 5 - access denied.

Error Handling and Verification

Add structured logging to every load path so failures are observable. WinCC exposes HMIRuntime.Trace for the diagnostics window and HMIRuntime.LogWrite for the system log:

Sub LoadConfig()
    Dim sVal, sPath
    sPath = "C:\Recipes\Config.ini"
    On Error Resume Next

    sVal = ReadINIValue(sPath, "Runtime", "BatchSize", "100")
    If Err.Number <> 0 Then
        HMIRuntime.Trace("INI read failed: " & Err.Number & " " & Err.Description & vbCrLf)
        Err.Clear
    Else
        SmartTags("BatchSize") = CInt(sVal)
        HMIRuntime.LogWrite "Config", "HMI", 0, _
            "BatchSize set to " & SmartTags("BatchSize")
    End If
End Sub

Verification checklist

1. Open WinCC Runtime. Confirm the diagnostics window (Start > Programs > Siemens Automation > WinCC Runtime Professional > WinCC Runtime - Diagnostics) shows the trace line.
2. Open the start screen and confirm the I/O field bound to BatchSize shows the value from the INI, not the project default.
3. Temporarily rename the file to Config.ini.bak and restart Runtime. The script should write the default value and emit a "CSV missing" or "INI read failed" trace. Confirm this behaviour because it proves the fallback path works.
4. Restore the file. Restart Runtime. Confirm the real value is loaded.
5. Check the Windows Event Viewer under Application for any WinCC Runtime errors with source CCAgent.

Troubleshooting Matrix

Comparison with Other Recipe Mechanisms

WinCC Professional also includes a native Recipes object (HMIRuntime.Recipes) that stores data in a binary .rdb file rather than plain-text CSV or INI. The native recipe object gives concurrent access, versioning, and a built-in view, but it requires the operator to actively load/save a recipe and it cannot be hand-edited outside WinCC. The CSV/INI approach documented here is appropriate when:

• An MES or ERP system must drop the file from outside the WinCC project.
• An engineer needs to edit values in Notepad or Excel.
• The startup value set is small (under a few dozen tags) and rarely changes.

For projects on Allen-Bradley PanelView Plus, the recipe import flow is fundamentally similar - browse to a .csv file via FactoryTalk View SE recipe import or PanelView Plus parameter file - but the script and tag namespaces are completely different. Likewise, AutomationDirect's C-more HMI offers a one-click Import Recipe Sheet action documented in the official C-more help system, where the operator selects a CSV from the project folder and the panel writes its values into a recipe structure automatically - no scripting required, but the import is manual and bound to a screen button rather than a startup event.

The WinCC CSV/INI approach occupies a middle ground: fully automated at Runtime start, but text-based and editor-friendly.

Field-Commissioning Notes

• Always create the recipe file before downloading the WinCC project so the script has something to read on first start.
• Wrap the loader in On Error Resume Next plus an Err.Clear at the end. An unhandled VBS error inside a scheduler task freezes subsequent tasks for that cycle and is hard to trace.
• Pre-validate the recipe with a checksum line at the bottom (e.g. ;SHA256=...). Read it in VBS and refuse to load if the checksum fails - this catches a truncated upload.
• Keep the file under 64 KB if the Runtime target is a panel with Windows Embedded Compact; larger files increase startup latency visibly.
• If the file is dropped by a Windows scheduled task, use FileSystemObject's GetFile.LastModified to detect changes and reload only when newer than the tag's last update time.

FAQ