WinCC HTML to PDF Conversion: VBScript, Acrobat, and Alternatives

Overview

Siemens WinCC operators frequently need to archive runtime process values, fault code text, and alarm summaries as portable, read-only documents. The native WinCC Report Designer outputs to a hardcopy spool, CSV, or RTF, but projects that produce HTML reports (typically via custom VBScript that joins the WinCC SQL archive with status tag dictionaries) cannot print directly to PDF through the standard layout designer. This article documents four production-proven paths for converting a WinCC-generated HTML file to PDF:

1. Native WinCC 7.4 SP1+ text-tag logging + Report Designer layout (no scripting required).
2. Report Designer with an ODBC dynamic object pointing at the archive database.
3. VBScript automation of the Adobe Acrobat AcroExch.App ActiveX interface (Acrobat full version, not Reader).
4. SQL Server Reporting Services / Business Intelligence export pipeline.

Each method has different hardware, licensing, and runtime-impact constraints. The decision matrix in Method Comparison below should be read first.

Prerequisites

Method Comparison

Method 1 — Native Text in WinCC TagLogging (7.4 SP1+)

Prior to WinCC 7.4 SP1, the Tag Logging archive could only persist numeric values. Any attempt to log a string tag (e.g., 1 = Running, 2 = Stopped, 3 = Fault Code, 4 = Unavailable) failed silently or returned datatype mismatch. Starting with WinCC 7.4 SP1, string-tag logging became officially supported. The decision path for ambiguous "WinCC 7.4" references is to verify the exact installed build in SIMATIC WinCC Explorer > Help > About: only 7.4.0.1 and later reliably expose this feature.

Steps to migrate an existing project:

1. Open Tag Logging editor.
2. Add a new archive tag, datatype String (8-bit) or Text (16-bit, double-byte). Length up to 256 characters.
3. Map your status dictionary (1=Running, etc.) via a derived text tag or Tag Conversion on the PLC side using a function block that writes both the integer code and the human-readable string.
4. Use the standard Report Designer > Alarm Logging Report or Tag Logging Report layout, choosing PDF as the printer destination directly — no HTML intermediate required.

This eliminates the entire HTML-to-PDF conversion chain for new projects.

Method 2 — Report Designer with ODBC Dynamic Database Object

When the HTML report is generated because the layout references fields the standard report templates cannot reach (e.g., computed columns, custom joins, or string translations), you can keep using your VBScript + SQL pipeline but route the result through the Report Designer via the Dynamic Database Object:

1. Open Report Designer.
2. Insert a Dynamic Object > ODBC Database into a page layout.
3. Configure the connection to the same SQL instance holding the WinCC archive. The Connection string uses the same ODBC 32-bit DSN defined under SysWOW64\odbcad32.exe.
4. Paste your SQL query. Example for the status dictionary joined with the TagLogging archive:

   SELECT
     a.Timestamp,
     a.TagName,
     a.RealtimeValue,
     b.TextValue,
     b.Description
   FROM dbo.Archive a
   LEFT JOIN dbo.StatusLookup b
     ON a.TagName = b.TagName
    AND a.RealtimeValue = b.IntCode
   WHERE a.Timestamp BETWEEN '2024-01-01' AND '2024-01-02'
   ORDER BY a.Timestamp DESC;
   

5. Set the print destination to PDF file in the report's Properties > Print Job.

This is the cleanest path when you already have the SQL knowledge: you keep the report server-side, version-controlled in the WinCC project, and the resulting PDF is generated by WinCC's own spooler with no VBScript error surface.

Method 3 — VBScript Automation of Adobe Acrobat

Use this path when the HTML report is already produced by an existing VBScript routine and you want a drop-in PDF conversion step at the end of that script.

3.1 Install and Verify Acrobat ActiveX

1. Install full Adobe Acrobat (not Reader). A 30-day trial is acceptable for commissioning.
2. Verify the COM class is registered:

   cscript //nologo -e:vbscript "MsgBox CreateObject(""AcroExch.App"").Version"
   

   Expected result: a message box showing the Acrobat version (e.g., "19.010.20098"). If it fails with Error 429, the install is Reader-only or the COM class was unregistered.
3. Re-register the class manually if needed:

   regsvr32 "C:\Program Files (x86)\Adobe\Acrobat DC\Acrobat\acrobat.tlb"
   

3.2 Conversion Subroutine

' WinCC_VBS - HtmlToPdf.vbs
' Requires: Adobe Acrobat (full), not Reader.
Option Explicit

Const g_sHtmlPath = "C:\WinCC_Reports\DailyReport.html"
Const g_sPdfPath  = "C:\WinCC_Reports\DailyReport.pdf"

Sub HtmlToPdf_Acrobat(sHtml As String, sPdf As String)
    Dim oApp, oAvDoc, oPDDoc, oJSObject
    Dim sTmpPdf As String

    On Error GoTo EH

    Set oApp = CreateObject("AcroExch.App")
    oApp.Hide                                           ' silent run
    Set oPDDoc = CreateObject("AcroExch.PDDoc")

    ' Step 1: open the HTML as a PDF via the Internet Explorer PDFMaker hook
    '         (Acrobat converts HTML to PDF internally before display)
    If Not oPDDoc.Open(sHtml) Then
        Err.Raise vbObjectError + 1001, , "Open HTML failed: " & sHtml
    End If

    ' Step 2: save to the target path
    sTmpPdf = Replace(sHtml, ".html", "_tmp.pdf")
    If Not oPDDoc.Save(1, sTmpPdf) Then                ' 1 = PDSaveFull
        Err.Raise vbObjectError + 1002, , "Save PDF failed"
    End If
    oPDDoc.Close

    Set oPDDoc = Nothing
    oApp.Exit
    Set oApp = Nothing

    ' Step 3: rename / move to final destination
    Dim oFSO: Set oFSO = CreateObject("Scripting.FileSystemObject")
    If oFSO.FileExists(sPdf) Then oFSO.DeleteFile sPdf, True
    oFSO.MoveFile sTmpPdf, sPdf
    Set oFSO = Nothing

    Exit Sub
EH:
    If Not oPDDoc Is Nothing Then oPDDoc.Close
    If Not oApp    Is Nothing Then oApp.Exit
    Err.Raise Err.Number, Err.Source, Err.Description
End Sub

' --- driver: invoke from a WinCC button or scheduled task ---
Call HtmlToPdf_Acrobat(g_sHtmlPath, g_sPdfPath)

3.3 Alternative: Convert HTML String to PDF Directly

When the HTML payload lives in memory (a VBScript string built from Recordset.GetString), write it to a temp .htm first, then convert. The same AcroExch.PDDoc.Open method accepts both file paths and rendered strings via the AcroExch.HTMLControl plugin — but the file-based path is the most stable across Acrobat XI, DC 2015, and DC 2024.

Method 4 — SQL Server Business Intelligence / SSRS

For multi-site or web-delivered reporting, the highest-density path is:

1. Build a Reporting Services (SSRS) report that queries the WinCC archive DB (linked server or direct).
2. Schedule the report with a subscription set to delivery type: File Share, file format PDF, and a recurring schedule (e.g., 23:55 daily).
3. Alternative free path: SQL Server Data Tools + a Report Builder report, executed by a SQL Server Agent job that runs a PowerShell Export-RsReport call.

Output formats supported by SSRS subscriptions include CSV, HTML, PDF, Word, Excel, XML, MHTML, and image (TIFF/PNG). This list is the same set returned by SSRS RenderFormat enumeration.

Field-Commissioned Procedure (End-to-End)

1. Confirm the HTML file exists and is well-formed. Validate with a quick cscript //nologo HtmlToPdf.vbs from a command line first; isolate HTML-generation errors from PDF-conversion errors.
2. Confirm CreateObject("AcroExch.App") succeeds before scheduling anything. A failed create here is the root cause of 80% of "works on my machine, fails on SCADA server" reports.
3. Schedule the script via Windows Task Scheduler with the credential of the WinCC Runtime user. The script must run in a session where Acrobat is allowed to spawn a child process; do not run as SYSTEM.
4. From within WinCC, trigger the script by adding a button event:

   Sub OnClick(ByVal Item)
       Dim oShell: Set oShell = CreateObject("WScript.Shell")
       oShell.Run "cscript //nologo C:\Scripts\HtmlToPdf.vbs", 0, True
       Set oShell = Nothing
   End Sub
   

   Wait parameter True blocks the WinCC thread until the PDF is ready, preventing concurrent overwrites of the output file.
5. Add a post-step that copies the PDF to a network share or sends it via SMTP. Many sites use blat or a PowerShell Send-MailMessage call for emailing daily reports.

Troubleshooting Matrix

Performance and Sizing Notes

A single Acrobat PDFMaker pass over a 200-row HTML table takes approximately 1.5-3.5 s on a WinCC 7.4 SCADA server (Xeon E3-1270, SATA SSD, 16 GB RAM). For batch runs exceeding 50 reports, prefer SSRS subscription batching over a serial VBScript loop — Acrobat is a heavy COM client and does not benefit from in-process parallelism. If a single WinCC project must generate hourly reports, consider a 1-minute out-of-phase stagger per report to keep CPU below 30% on the runtime server.

Security Hardening

1. Restrict the HTML source directory with an NTFS ACL that grants Modify only to the WinCC runtime account; the script should not accept arbitrary paths from operator input.
2. If the script reads from a user-supplied query, parameterize the SQL inside Method 2 to prevent injection — the Report Designer ODBC object supports bound parameters via ? placeholders.
3. Disable Acrobat's protected mode exceptions for the WinCC bin path; conversely, do not run Acrobat with Full Trust on a non-isolated DMZ SCADA server.

Verification Checklist

1. CreateObject("AcroExch.App") returns a valid object from a command prompt under the WinCC runtime user.
2. A known-good HTML file produces a non-zero, non-locked PDF of correct page count within 5 s.
3. The PDF opens in both Acrobat and Reader without security warnings.
4. Special characters, status dictionary text, and timestamp formats are searchable in the resulting PDF (i.e., they are real text, not rasterized).
5. Triggering the script from a WinCC button returns control to the operator within the expected window and the PDF is accessible from the configured network share.
6. Two consecutive runs do not collide on the output file (file-locking is correctly handled via FSO.DeleteFile before the second MoveFile).

FAQ