Configuring Trend Views with Database Data in WinCC TIA Portal

Overview: Trend Architecture in WinCC TIA Portal

WinCC TIA Portal – whether in the Comfort, Advanced, or Professional flavor – does not render trend curves from arbitrary external databases. The Trend view, the Online Trend Control, and the f(t) trend view all read from a single data source: HMI data logs configured inside the project tree under the HMI device's Historical data node. Each data log persists its samples to a file on the panel's storage media (internal flash on compact panels, SD card on Comfort Panels, local disk or network share on a PC Runtime). Once a data log exists, any trend control on any screen can be bound to it and will render both the live tail and any stored historical segments within the trend's visible window.

This single-source architecture has three practical consequences that drive every configuration decision in this guide:

• Direct ODBC, OLE-DB, or SQL queries against an external relational database (SQL Server, MySQL, Oracle, PostgreSQL, SQLite) are not supported from inside the runtime trend view. The trend control reads only the panel's own .csv or .rdb log files. For SQL/SAP/ERP archiving, deploy the SIMATIC WinCC Archive Connector as a separate Windows service.
• If process values are written from a VBScript to a free-form .csv file, the trend view cannot natively re-open that file. The values must first be inside a configured data log (or imported by the Archive Connector before the trend renders).
• Date-wise or batch-wise "report" trends are achievable by either (a) splitting logs by shift or batch using separate data log files or segmented storage, or (b) post-processing the trend's exported .csv via Excel or the Archive Connector. There is no direct SQL-style query language exposed at runtime.

Prerequisites

Verify the engineering environment, panel firmware, and storage capacity before configuring historical trends. The matrix below is the recommended baseline; values reflect Siemens documentation for TIA Portal V16/V17/V18.

Configuring HMI Data Logs

Data logs are the storage layer. Create them before configuring the trend view, otherwise the trend's source dropdown will be empty.

1. In the TIA Portal project tree, expand the HMI device, then expand Historical data. Right-click and choose Add new data log.
2. Name the log semantically (e.g. BatchReport_ProcessValues, Reactor_TempTrend). Avoid spaces, umlauts, and special characters – the file on the panel becomes <Name>.csv.
3. Add logging tags. Click Add in the tag list and choose HMI tags. Each tag occupies one column in the log file. The first column is always the timestamp.
4. Select the Logging mode:
   • Cyclic – log every N seconds. Choose for fixed-rate sampling or process signature trends.
   • On change – log when the tag value changes (with optional hysteresis). Choose for event-driven data and minimal file size.
   • On demand via script – the recommended mode for variable-time logging driven by the PLC. Use the AddRecord method from a VBScript.
5. Set the Logging cycle (1 s default). For data reduction, set the cycle higher than the acquisition cycle of the underlying HMI tag – values are averaged or decimated internally.
6. Set Storage method:
   • Circular buffer – oldest entries are overwritten.
   • Segmented – a new file is opened on a daily / shift / trigger basis. Best for batch reports.
   • Do not overwrite – logging stops when full. Use for compliance / FDA-style records.
7. Configure Storage location under Runtime settings → Historical data:
   • Comfort Panel default: \Storage Card SD\Logs\
   • PC Runtime default: C:\ProgramData\Siemens\Automation\Logs\
   • Network share (PC Runtime only): \\server\share\hmi_logs\ with the runtime service account granted write access.

Data Log Property Matrix

Configuring the Trend View

Trend views are placed on a screen and bound to one or more data logs. There are three trend controls in TIA Portal; pick by use case:

Step-by-step for the standard Trend view:

1. Open the desired HMI screen in the editor. Drag Trend view from the toolbox onto the screen.
2. In the properties pane, navigate to Trend → Trend areas and click Add to create one trend line per process tag you want to plot.
3. For each trend area, configure Source settings:
   • Data source: Data log (the only historical source).
   • Data log: select the log created above.
   • Tag / column: select the column to plot. For HMI tags named ReactorTemp, the column is logged under that exact name.
   • Trend type: choose Real-time trend, Historical trend, or Real-time/historical trend with common X-axis. The combined mode is the default for shift-report screens.
4. Configure the Time axis:
   • Mode: Point of time (timestamps absolute) or Time interval (relative window).
   • Range: e.g. 60 minutes, 8 hours, 24 hours, 7 days.
   • Zoom: enable operator zoom in the Toolbar configuration.
5. Configure the Value axis: scaling, line color, line weight, trigger tag for dynamic limits.
6. Under Online → Export, enable Export data record and assign a target path. The export writes the visible window to a .csv at the operator's request.

For a historical-only trend (date or batch report), choose Historical trend and bind the Start time tag and End time tag as HMI Date_Time tags. The operator – or a script – sets the window and the trend re-renders the stored segment.

Variable-Interval Logging with VBScript

If the sampling interval must vary based on a value or trigger written by the PLC (the situation in the original scenario: a VB script reads variable-time-interval data from the PLC), the cleanest pattern is to write a small VBScript that the runtime calls on a tag change. There are two practical approaches; choose by data volume.

Approach 1 – Toggle logging on/off and let the data log use its configured cycle. Best when the PLC tells the HMI when to start and stop, and the HMI uses a fixed internal cycle:

' HMI script – triggered by the OnChange event of tag "LoggingEnable" (Bool)
Sub StartStopLogging(ByVal Item)
    If SmartTags("LoggingEnable").Value = True Then
        SmartTags("BatchReport_ProcessValues").StartLogging
    Else
        SmartTags("BatchReport_ProcessValues").StopLogging
    End If
End Sub

Approach 2 – Write a single row to the data log on each PLC trigger (variable timestamps, single row per trigger). Best when the PLC dictates both the trigger time and what to capture:

Sub WriteLogRow(ByVal Item)
    Dim oLog
    Set oLog = SmartTags("BatchReport_ProcessValues")
    oLog.AddRecord Array( _
        Now, _
        SmartTags("Temperature_PV").Value, _
        SmartTags("Pressure_PV").Value, _
        SmartTags("Flow_PV").Value _
    )
End Sub

Wire the script to the OnChange event of a trigger tag (e.g. LogTrigger rising edge) or schedule it on a 100 ms cycle if the PLC pulse rate is faster than the smallest reliable HMI tick. On Comfort Panels, do not schedule faster than 100 ms – the script engine cannot guarantee sub-100 ms execution.

For per-batch file separation, rename the data log path or trigger a new segment via LogClose / LogOpen at batch boundary:

Sub CloseAndReopenLog(ByVal Item)
    SmartTags("BatchReport_ProcessValues").StopLogging
    ' Optional: archive the .csv via filesystem object
    Dim fso, src, dst
    Set fso = CreateObject("Scripting.FileSystemObject")
    src = "\Storage Card SD\Logs\BatchReport_ProcessValues.csv"
    dst = "\Storage Card SD\Archive\Batch_" & Format(Now, "yyyymmdd_hhnnss") & ".csv"
    If fso.FileExists(src) Then fso.MoveFile src, dst
    SmartTags("BatchReport_ProcessValues").StartLogging
End Sub

Date-wise and Batch-wise Historical Trend Reports

To produce a "report" view that mimics an Excel export of one shift or one batch:

1. Use separate data logs per batch, or rely on TIA's automatic timestamped segment naming (with Storage method = Segmented, each new segment becomes <DataLogName>_<YYYYMMDD>_<HHMMSS>.csv).
2. From runtime, navigate the operator to a Trend view configured as Historical. Provide an input field bound to StartTime and EndTime HMI tags. The operator enters the shift window and confirms – the trend re-renders the stored segment.
3. Use the trend's built-in Export function (Online → Export data record) to write the visible window to USB or a network share. The exported file is .csv and opens directly in Excel.
4. For SQL/SAP/ERP archiving, deploy the SIMATIC WinCC Archive Connector (separate installation). Configure an ODBC data source pointing at the database. The Connector polls the panel's log directory and inserts rows into the configured SQL tables.

Sample Operator Screen Composition

Storage, File Format, and Limits

SQL / SAP Integration via WinCC Archive Connector

The WinCC Archive Connector is a Windows service that reads the panel's .csv / .rdb files and inserts the rows into a relational database through ODBC. It is the supported bridge between WinCC TIA logs and any SQL-based MES / ERP / historian system. Configuration steps:

1. Install the Archive Connector on a Windows server with network access to both the panel (or its storage share) and the target SQL server.
2. Create a 32-bit ODBC data source (odbcad32.exe) pointing at the target database. Use the SQL Server Native Client or the provider supplied with your RDBMS.
3. In the Archive Connector configuration tool, map each data log to a target table. The Connector creates the table on first run if the database user has DDL rights.
4. Set the polling interval (default 10 s) and the file-source path. UNC paths to a PC Runtime's log directory are preferred over FTP.
5. Monitor the Connector log under %ProgramData%\Siemens\ArchiveConnector\Logs\.

Performance and Optimization

Troubleshooting Matrix

Field-Proven Caveats

• WinCC Trend view will not directly query SQL Server, MySQL, or Oracle. The WinCC Archive Connector is the supported bridge for that pattern.
• Writing values to a free-form .csv from a VBScript bypasses the data log; the trend view will not see those rows. Either funnel the writes through AddRecord on a configured data log, or import the .csv into Excel for the report.
• On Comfort Panels, the data log file is closed and re-opened each cycle to limit data loss on power-cut. This is why timestamps may appear off by one cycle if the panel is power-cycled while a write is in flight.
• On change logging only fires when the value changes by more than the configured hysteresis (default 0). Set the hysteresis deliberately for floating-point tags to avoid logging every analog noise tick.
• Multiple HMI connections to the same PLC tag should not log to the same data log file – race conditions on file flush may cause torn rows.
• Compressed .rdb logs cannot be opened in Excel directly. Export them via the Archive Connector or convert with the runtime's Export function.
• If the SD card is removed while runtime is active, the next write fails silently and the panel raises system event 13002. The trend view will show a flatline gap.
• Do not name data logs starting with a digit or containing umlauts; some Comfort Panel firmwares reject these at boot.
• On PC Runtime, the runtime service account must have write permission to the configured log path. Network shares should use a service account with a non-expiring password.
• When migrating from WinCC flexible 2008 to TIA Portal, legacy Archive tags map to Data logs. The on-disk format changes; archive the legacy files before the migration.

Migration to Unified Comfort Panels

If the project is being migrated to a SIMATIC HMI Unified Comfort Panel (e.g. MTP700 / MTP1000 / MTP1500 / MTP1900 / MTP2200), the data log concept is preserved, but the API surface differs:

• Data logs are configured under Historical data with the same property set.
• Trend controls are Trend view (Unified) and Online Trend Control (Unified).
• The script model is JavaScript instead of VBScript. The AddRecord method is replaced by the DataLog.write JavaScript method on the runtime API.
• Storage defaults to /media/simatic/Logs/ on the Unified panel.

Plan a re-test of the entire logging path after any TIA Portal upgrade; behavior changes between major TIA Portal releases have historically affected the data log flush timing on Comfort Panels.