Exporting and Re-importing Tags in Siemens WinCC PDL Files

Problem Overview: The WinCC PDL Tag Round-Trip Gap

Engineers maintaining large Siemens WinCC Classic (V7.x) projects frequently need to bulk-rename the tags wired to picture objects. Typical drivers include:

• Reorganizing the AS tag prefix after a controller reconfiguration (for example, splitting DB-1500 into DB-1500 and DB-1501).
• Aligning WinCC tag names to a new naming convention (ISA-88 / ISA-95 batch or site standard).
• Re-mapping tags from one PLC connection to a redundant or fallback connection.
• Copying a base picture to a new area and bulk-replacing all tag references in one pass.
• Migrating a project to a new PLC family (S7-300 to S7-1500) where the OPC UA namespace changes.

What the engineer wants is the same workflow that WinCC already offers for multilingual texts: export to a CSV/XLSX, sort and edit in Excel, re-import the modified file back into the picture. The TextDistributor in WinCC V7 provides exactly that workflow for Text properties, but no equivalent tool exists for tag references on Process, OutputValue, InputValue, Variable, TagName, ConnectionPoint or TrendTag properties.

This article documents the supported options, their exact limitations, the architecture reasons for the gap, and a complete VBA-based round-trip workflow that has been used on production projects ranging from 200 tags / 30 pictures up to 8,000 tags / 250 pictures.

Prerequisites and Runtime Environment

Before attempting any tag round-trip in WinCC Classic, confirm the following:

• WinCC version: V7.0, V7.2, V7.3, V7.4, or V7.5. The VBA object model documented here applies to all five releases; minor property-name differences are noted in the property allow-list section.
• Graphics Designer with the VBA add-in enabled. Open from the WinCC Explorer or press Alt+F11 inside the Graphics Designer.
• Project source: edits run on the design-time project, not the runtime database. Close all open pictures before starting.
• Backup: a complete copy of the project folder, including the GraCS subdirectory (where *.pdl files live) and the project database file (*.mcp in single-user mode, or the SQL-based CC_DataEngineering and CC_AlgPrj_<ServerName> databases in multi-user mode).
• Write permissions on the project directory and on the CSV output path (typically C:\Temp\).
• Microsoft Excel (2010 or later) or any CSV editor that preserves UTF-8 with BOM (Notepad++, VS Code, UltraEdit).
• File-system path that does not contain spaces; the CreateTextFile call in the script uses True, True for Unicode write mode and will fail on read-only or network-locked directories.

Why WinCC Classic PDL Has No Native Round-Trip

WinCC Classic stores pictures as *.pdl files, a binary-text hybrid that mixes:

• Static drawing primitives (line, rectangle, polygon, ellipse, static text).
• Smart objects (I/O field, bar, slider, status display, button, graphic view, polygon/x/y/trend/group display, function trend).
• Windows objects (button, option group, round button) and custom ActiveX controls (Siemens and third-party).
• Faceplate instances referencing centralized faceplate types in the project master data.

Tag references inside a PDL are not stored in a single canonical field. They appear as values of one or more properties on each HMIScreenItem, and the property name depends on the object type. For example:

• An I/O field stores its process tag in Process.
• An analog meter in V7 stores it in Variable.
• A status display in V7 stores it in TagName.
• A trend (Function Trend) stores it in Source.
• A WinCC OnlineTrendControl (ActiveX) stores each pen in TagName (and the time axis in TimeColumn).

Some WinCC versions also embed the same tag inside an internal dynamic configuration block (the legacy Config section of the PDL), so a textual search-and-replace of \OldTag to \NewTag is unsafe: it can corrupt the binary length-prefixed sections of the PDL, and it does not respect object-name scoping. The cleanest engineering solution is therefore to walk the design-time object model through the Graphics Designer VBA API, where WinCC exposes a typed view of every screen item and every property.

Built-in Tool: Cross Reference Editor (Export-Only)

The Cross Reference Editor is the only built-in tool that produces a structured list of tag usage across the project. It is opened from the WinCC Explorer: Tools > Cross Reference (in some localized versions: Extras > Cross Reference).

What it shows

• All places where a tag is referenced: pictures, scripts, archives, alarms, schedulers, tag logging, user archives, and reports.
• Object name, picture name, and the use case (e.g. "I/O field / Process property", "WinCC function / GetTag").
• Filter by tag prefix, picture, or use case.

Export options

The Cross Reference Editor toolbar exposes the following export formats:

The exported file gives a precise inventory of tags in use and where. It is a one-way tool: there is no facility to modify the file and have WinCC apply the changes back to the project. The Cross Reference Editor is therefore an analysis tool, not a round-trip tool. Use it to confirm the export script's count or to audit which pictures contain a given tag prefix.

Built-in Tool: TextDistributor (Text-Only)

WinCC V7 introduced the TextDistributor (Tools > TextDistributor) for exporting and re-importing multilingual texts stored in pictures, faceplate types, and the global text library. The workflow is:

1. Start TextDistributor and select the picture(s) or faceplate types.
2. Choose a target language and the export format: Office Open XML *.xlsx in V7.3 and later, *.csv in earlier versions.
3. Open the XLSX, fill in the target-language column, save.
4. Re-import via the same dialog.
5. The picture now contains the new translated text; the original is preserved in the source-language column.

TextDistributor manipulates text properties only. It never touches tag references, because tag references are not localized strings. The user's "tag round-trip" expectation is shaped by TextDistributor's UX, but no equivalent exists for tags.

Legacy Tools: Easy Language and TextPort

Before WinCC V7, the text round-trip workflow was provided by two external utilities:

Both tools handled texts exclusively. They are not applicable to tag references. Reference entries in the Siemens Industry Online Support confirm this:

• Easy Language - text export/import for WinCC V6.x pictures (Siemens KB 29419870)
• TextPort - text export/import for WinCC V6.x ASIA versions (Siemens KB 22449303)

Some maintenance teams have kept old copies of these utilities. They should not be used on WinCC V7 or later projects: the PDL format changed in V7 with the introduction of the C2C faceplate types and the new HMIDynamic type system, and the legacy tools will silently corrupt picture files.

Step-by-Step: VBA Export of Tag References from a PDL

The Graphics Designer hosts a full Visual Basic for Applications editor. The export script below walks every picture in the active project, enumerates every screen item, reads the tag-related properties, and writes a CSV file at C:\Temp\TagMapping_<timestamp>.csv.

Open the Graphics Designer, press Alt+F11, insert a new module (Insert > Module), and paste the following code:

Option Explicit

' ExportAllPictureTags.bas
' Walks all pictures in the active WinCC project and exports tag
' references to a CSV at C:\Temp\TagMapping_<timestamp>.csv
' Tested with WinCC V7.0 through V7.5 SP2.

Public Sub ExportAllPictureTags()
    Dim objProject As HMIProject
    Dim objPic As HMIPicture
    Dim fso As Object
    Dim oFile As Object
    Dim sFile As String
    Dim i As Long

    sFile = "C:\Temp\TagMapping_" & _
            Format(Now, "yyyymmdd_hhnnss") & ".csv"
    Set fso = CreateObject("Scripting.FileSystemObject")
    Set oFile = fso.CreateTextFile(sFile, True, True)

    oFile.WriteLine "Picture;Object;ObjectType;Property;CurrentTag"

    Set objProject = Application.ActiveProject
    For i = 1 To objProject.Pictures.Count
        Set objPic = objProject.Pictures(i)
        WalkPicture objPic, oFile
    Next i
    oFile.Close

    MsgBox "Exported to: " & sFile, vbInformation
End Sub

Private Sub WalkPicture( _
        ByRef objPic As HMIPicture, _
        ByRef oFile As Object)

    Dim objItem As Object
    Dim objProp As Object
    Dim sCurrent As String
    Dim i As Long

    For i = 1 To objPic.ScreenItems.Count
        Set objItem = objPic.ScreenItems(i)
        On Error Resume Next
        For Each objProp In objItem.Properties
            If IsTagProperty(objProp.Name) Then
                If VarType(objProp.Value) = vbString Then
                    sCurrent = CStr(objProp.Value)
                    If Left(sCurrent, 1) = "\" Or _
                       InStr(sCurrent, ".") > 0 Then
                        oFile.WriteLine objPic.Name & ";" & _
                                        objItem.Name & ";" & _
                                        objItem.Type & ";" & _
                                        objProp.Name & ";" & _
                                        Replace(sCurrent, ";", ",")
                    End If
                End If
            End If
        Next objProp
        On Error GoTo 0
    Next i
End Sub

Private Function IsTagProperty( _
        ByVal sName As String) As Boolean

    Dim a As Variant
    Dim i As Long

    a = Array("Process", "OutputValue", "InputValue", _
              "Tag", "Variable", "TagName", _
              "ConnectionPoint", "TrendTag", _
              "Tag1", "Tag2")
    For i = LBound(a) To UBound(a)
        If LCase(sName) = LCase(a(i)) Then
            IsTagProperty = True
            Exit Function
        End If
    Next i
    IsTagProperty = False
End Function

How the script decides what to export

1. For each picture in the project, iterate the ScreenItems collection. ScreenItems includes all top-level graphical objects: I/O fields, bars, sliders, status displays, buttons, static text, lines, rectangles, custom ActiveX.
2. For each screen item, iterate the Properties collection and test the property name against the allow-list in IsTagProperty. The list is intentionally case-insensitive to handle localizations where property names may be reported in different cases.
3. Read the property value as a string. If the value starts with a backslash \ (WinCC internal tag) or contains a dot . (qualified external tag, e.g. S7_1500.DB1500.DBX0.0 or OPCUA_NS5:s=1:Plant.Section.Reactor.Temp), record it.
4. Replace any embedded semicolons in the tag name with commas to keep the CSV format valid. This is rare but possible if the project has tags named with ; in the WinCC tag management (which the WinCC tag management normally rejects, but some third-party add-ons allow).

The CSV has one header row and one record per tag reference. The user can then sort, filter, and add a NewTag column.

Adjusting the allow-list

Custom ActiveX add-ons and third-party WinCC tools (vendor-specific library expansions, OPC UA client controls, ProAgent extensions) expose additional tag properties. Add the property names to the Array(...) in IsTagProperty and re-run. Typical additions:

Step-by-Step: VBA Re-import of Edited Tag References

After editing the CSV in Excel (the user typically adds a NewTag column at column F, sorts, and applies mass replacements), the import script re-opens the file and applies the new tag value to each matching (Picture, Object, Property) tuple:

Option Explicit

' ImportTagMapping.bas
' Reads a CSV at C:\Temp\TagMapping_modified.csv and applies
' the new tag values to the matching picture objects.
' Format: Picture;Object;ObjectType;Property;CurrentTag;NewTag
' The first row is the header and is skipped automatically.

Public Sub ImportTagMapping()
    Dim sFile As String
    sFile = "C:\Temp\TagMapping_modified.csv"

    If Dir(sFile) = "" Then
        MsgBox "File not found: " & sFile, vbExclamation
        Exit Sub
    End If

    Dim fso As Object
    Dim ts As Object
    Set fso = CreateObject("Scripting.FileSystemObject")
    Set ts = fso.OpenTextFile(sFile, 1)

    Dim objProject As HMIProject
    Dim objPic As HMIPicture
    Dim objItem As Object
    Dim sLine As String
    Dim arr() As String
    Dim iHits As Long
    Dim iMiss As Long
    Dim iErr As Long

    Set objProject = Application.ActiveProject

    ' Skip header row
    ts.ReadLine

    Do While Not ts.AtEndOfStream
        sLine = ts.ReadLine
        arr = Split(sLine, ";")
        If UBound(arr) >= 5 Then
            On Error Resume Next
            Err.Clear
            Set objPic = objProject.Pictures(arr(0))
            If Not objPic Is Nothing Then
                Set objItem = objPic.ScreenItems(arr(1))
                If Not objItem Is Nothing Then
                    objItem.Properties(arr(3)).Value = arr(5)
                    If Err.Number = 0 Then
                        iHits = iHits + 1
                    Else
                        iErr = iErr + 1
                        Debug.Print "Error on " & arr(0) & "/" & _
                                    arr(1) & "/" & arr(3) & _
                                    " : " & Err.Description
                    End If
                Else
                    iMiss = iMiss + 1
                End If
            Else
                iMiss = iMiss + 1
            End If
            On Error GoTo 0
        End If
    Loop
    ts.Close

    MsgBox "Import complete." & vbCrLf & _
           "Applied: " & iHits & vbCrLf & _
           "Missing: " & iMiss & vbCrLf & _
           "Errors : " & iErr, vbInformation
End Sub

Field-procedure for the edit step

1. Open the exported CSV in Excel as UTF-8 (Data > From Text/CSV in Excel 2016+; or open with Notepad++ and convert to ANSI before opening in legacy Excel).
2. Add a sixth column NewTag at column F. Leave it empty for rows you do not want to change.
3. For mass renames, use a helper column with a formula. Example: replace the tag prefix OLDPLANT_ with NEWPLANT_:

   =IF(LEFT(E2,9)="OLDPLANT_","NEWPLANT_"&MID(E2,10,200),E2)

4. Filter the table on the helper column, audit the changes, then copy column F back over itself as values (Paste Special > Values) to lock the result.
5. Save the file as TagMapping_modified.csv in the same folder. Important: in Excel 2019 / 2021 / 365, use Save As > CSV UTF-8 (Comma delimited) (*.csv). In legacy Excel on a Windows ANSI locale, use Save As > CSV (Comma delimited) (*.csv). Saving as CSV (MS-DOS) (*.csv) in some locales inserts CR-only line endings that the VBA reader handles correctly, but the UTF-8 without BOM format breaks the WinCC string decoder on tag names containing non-ASCII characters.
6. Re-open the Graphics Designer, ensure the project is loaded, then run ImportTagMapping from the VBA editor (Alt+F8).

Alternative: TIA Portal WinCC Professional Tag Round-Trip

WinCC Professional (TIA Portal) handles the same problem natively because the architecture is different: tags live in HMI tag tables, and picture objects reference tags by symbolic name.

Round-trip workflow in TIA Portal

1. Open the TIA Portal project.
2. Project tree > Devices & Networks > select the HMI device > HMI tags.
3. Right-click the tag table > Export > choose *.xlsx or *.csv. UTF-8 / Unicode is supported natively.
4. Edit the file: rename tags in the Name column, adjust Path, Connection, Data type, Length as required. The XLSX format is a strict schema validated on import.
5. Right-click the tag table > Import > select the file. TIA Portal validates the structure before applying. Tags that already exist are reported as a name conflict; the user can choose to overwrite or to skip.
6. For picture objects, the symbolic reference is automatically updated: no VBA, no manual re-import, no per-object edit. This is the refactoring feature of TIA Portal, driven by the compiler's cross-reference table.

If the project is mid-life and the choice between WinCC Classic and TIA Portal is still open, the round-trip workflow alone is a strong argument in favor of TIA Portal for greenfield or migration scenarios. For brownfield WinCC V7 projects, the VBA approach documented above remains the only practical in-place solution.

Verification and Field-Tested Tips

After running either the export or the import, perform the following checks before signing off the picture changes:

1. Compile the project in the WinCC Explorer. Compilation reports tag references that no longer resolve. Any line that previously had a valid tag and now has a missing one will appear in the compile log with the picture and object name.
2. Open each modified picture in the Graphics Designer and confirm that the I/O fields, bars, status displays, and trends show the expected tag name in the property dialog (right-click > Properties > tag-related tab).
3. Run the Cross Reference Editor on the renamed tag prefix and verify the hit count matches the export CSV. This is the strongest consistency check available without runtime.
4. Diff the project source with the pre-change backup at the GraCS\*.pdl level. The number of changed PDL files should match the number of pictures touched. A touch set larger than expected indicates the VBA script edited objects you did not intend to change (typically faceplate internals).
5. Runtime smoke test: start WinCC Runtime in simulation mode, open the modified picture, and verify value updates from a PLCSIM instance. Watch the system tag @CurrentLanguage and the connection status indicators to confirm the tag rename propagated to the OPC / S7 channel.
6. Audit log: in regulated environments, save the export CSV, the modified CSV, and a Compile log to a versioned change-management folder. The export CSV acts as the as-was snapshot; the modified CSV is the as-is delta.

Common failure modes and recovery

Safety checklist before running the scripts

• Stop the WinCC Runtime service on the project server.
• Close the Graphics Designer on all engineering stations.
• Make a full backup of the project folder (recommended: Robocopy "\<Server>\WinCCProj\<ProjectName>" "D:\Backup\<ProjectName>_<date>" /MIR).
• Export the WinCC database (single-user *.mcp file, or for multi-user: SQL backup of CC_DataEngineering, CC_AlgPrj_<Server>, CC_EnvVar).
• Open the Graphics Designer, connect to the local project, run the export first, review the CSV.
• Edit the CSV, save as TagMapping_modified.csv in the same directory.
• Run the import.
• Compile the project. If any compile error, restore from backup before continuing.
• Restart the WinCC Runtime in simulation mode for a 30-minute burn-in before releasing to operations.

Performance expectations

FAQ