WinCC Flexible 2008 Hourly, Daily, Weekly, Monthly Tag Logging

1. Overview: Long-Term Historical Logging on WinCC Flexible 2008

WinCC Flexible 2008 (part of the legacy SIMATIC HMI toolchain) supports continuous tag logging and historical trending. The archived values can be aggregated on the HMI runtime into multiple time windows: hourly (1 h), daily (24 h), weekly (7 d) and monthly (≈30 d). This is the standard technique for replacing missing "report" generators on Comfort, Multi Panel, Mobile Panel, TP 177/270/277 and OP 277 platforms where the operator needs to scroll back through shifts and days to investigate process behaviour.

This reference covers a 20-tag logging scenario (2 analog process tags + 18 internal/MW-MD values generated by the PLC logic). It details archive creation, cycle selection, memory-tag logging, Trend View configuration, button-driven time-range switching via VBScript and runtime verification.

2. Prerequisites

Verify that the target panel supports archives. Operator panels of the 170-series (TP 170B, OP 170B) cannot log. Comfort panels log natively in TIA Portal; on WinCC Flexible 2008 the Multi Panel 177/277/377 and Touch Panel 277/377 are the supported archive targets. See the WinCC Flexible 2008 system manual for the panel-specific archive matrix.

3. Tag Archive Architecture

WinCC Flexible stores values in a Tag Logging archive. Two archive types are available:

For a 20-tag continuous logging application a sequence archive is mandatory, otherwise data older than the panel's RAM ring buffer is lost.

3.1 Create the Tag Archive

1. In the project tree, right-click Tag Logging → New Archive.
2. Name: ProcessArchive_1s (or per your logging cycle).
3. Storage location: File (CSV / RDB).
4. Archive mode: Segmented circular log with a segment size of 500 kB or 1 day, whichever is reached first. Daily, weekly and monthly windows survive restart because every segment header records an absolute time stamp.
5. Set the maximum segment count. A conservative value for 20 tags @ 1 s logging is 30 segments × 500 kB ≈ 15 MB; this gives roughly 90 days of data before overwriting the oldest segment.

4. Configuring the 20 Logged Tags

4.1 Analog Process Tags (2)

For the two external analog values coming from the PLC (e.g. DB1.DBD0 temperature, DB1.DBD4 pressure):

1. Open Tag Logging → Tags and add a new tag.
2. Select the source: external tag, e.g. Temperature (PLC DBW).
3. Set Acquisition mode = Cyclic continuous.
4. Set Acquisition cycle = 1 s (or 500 ms — confirm panel capability).
5. Assign to ProcessArchive_1s.
6. Set limits if scaling/range-bar is desired: Lower = 0, Upper = 100, or scaled to engineering units.

4.2 Internal / MW-MD Logic Tags (18)

WinCC Flexible can log internal tags that exist only in the HMI (e.g. derived MW/MD values calculated from the PLC logic). Procedure:

1. In Communication → Tags create the internal tag, e.g. ShiftCounter as Int, ProdCount as DInt, Energy_kWh as Real.
2. Use a scheduled Scheduler task or a value-change event in the PLC/HMI to update these tags.
3. Open Tag Logging → Tags, add each tag and choose Acquisition mode = On change if values change infrequently, or Cyclic if they must be polled.
4. Cycle recommendation: 2 s or 5 s for non-critical derived values.

5. Logging Cycle Selection Matrix

Total archive growth for the reference 20-tag project at the recommended mix: ≈ 2.7 M samples/day → roughly 22 MB of CSV before compression. A 4 GB MMC therefore retains ~180 days of full-resolution history.

6. Configuring the Trend View Control

WinCC Flexible provides the Trend View object for graphical historical display. It supports three time modes:

• Time range mode — operator picks start and end time, the control zooms into the window.
• Time axis mode — fixed time per screen pixel (e.g. 1 min/pixel, 1 h/pixel).
• Time base mode — relative offset from "now" (e.g. last hour, last 24 h, last 7 d, last 30 d).

For the hourly/daily/weekly/monthly switching requested by the customer, use the Time base mode. It is configured per trend:

1. Insert a Trend View on the desired screen.
2. Open Properties → Axis → Time axis.
3. Set Mode = Time base.
4. Set Time range = 1 h, 24 h, 7 d or 30 d for the four buttons.
5. Bind each visible trend row to one of the 20 logged tags (or a subset of the most important 6–8 for screen readability).
6. Enable Scroll bar and Ruler so the operator can read exact values at any cursor position.

7. VBScript to Switch Between Hourly, Daily, Weekly and Monthly Windows

The runtime cannot switch trend time-bases by a simple property; you must rebuild the trend source list with the new time-base offset. The cleanest approach is to maintain four Trend View objects layered at the same screen position with Visible toggled by buttons:

' WinCC Flexible 2008 — Trend View time-base switching
' Place four Trend Views: tvHour, tvDay, tvWeek, tvMonth
' All have Mode = "Time base", TimeRange = 1h / 24h / 7d / 30d

Sub ShowHour()
    SmartTags("tvHour").Visible = True
    SmartTags("tvDay").Visible  = False
    SmartTags("tvWeek").Visible = False
    SmartTags("tvMonth").Visible= False
End Sub

Sub ShowDay()
    SmartTags("tvHour").Visible = False
    SmartTags("tvDay").Visible  = True
    SmartTags("tvWeek").Visible = False
    SmartTags("tvMonth").Visible= False
End Sub

Sub ShowWeek()
    SmartTags("tvHour").Visible = False
    SmartTags("tvDay").Visible  = False
    SmartTags("tvWeek").Visible = True
    SmartTags("tvMonth").Visible= False
End Sub

Sub ShowMonth()
    SmartTags("tvHour").Visible = False
    SmartTags("tvDay").Visible  = False
    SmartTags("tvWeek").Visible = False
    SmartTags("tvMonth").Visible= True
End Sub

Wire each button's Click event to ShowHour, ShowDay, ShowWeek, ShowMonth respectively. The trend view automatically reads from the configured tag-logging archive; no script-side data fetch is needed.

8. Dynamic Time-Range Variant (Single Trend View)

If screen real estate is limited, swap a single Trend View's properties at runtime:

Sub SetRange(ByVal rangeStr)
    Dim tv
    Set tv = SmartTags("TrendView1")
    tv.TimeAxisMode = 1          ' 0 = Time range, 1 = Time base
    tv.TimeBaseRange = rangeStr   ' "0:01:00" / "1.00:00:00" / "7.00:00:00" / "30.00:00:00"
End Sub

Sub BtnHour_Click()  : SetRange "0:01:00"        : End Sub
Sub BtnDay_Click()   : SetRange "1.00:00:00"    : End Sub
Sub BtnWeek_Click()  : SetRange "7.00:00:00"    : End Sub
Sub BtnMonth_Click() : SetRange "30.00:00:00"   : End Sub

The property TimeBaseRange accepts a string in days.hours:minutes:seconds. See the WinCC Flexible scripting manual for the full VBS object model.

9. Logging Internal Tags Without a Trigger Source

For derived MW/MD values that are computed inside the PLC and only refreshed every cycle, the simplest robust logging pattern is:

1. Create a 100 ms OB in the PLC that copies the desired MD/MW words into a DB data block dedicated to logging.
2. Expose that DB to the HMI as external tags.
3. Mark each DB word for logging in Tag Logging → Tags with Acquisition mode = On change.
4. This prevents archive flooding when the value is identical, while still capturing every meaningful transition.

If the HMI must log purely internal (HMI-side) calculations, use the On change trigger with a hysteresis band, e.g. Limit = 0.5 °C for a temperature tag.

10. Runtime Verification

1. Compile and download the project to the panel.
2. Start the panel. Within one logging cycle the trend view should already show live data.
3. Press the Hour button — the X-axis compresses to the last 60 minutes, ruler shows mm:ss.
4. Press the Day button — X-axis expands to last 24 h, ruler shows hh:mm.
5. Press Week / Month — X-axis expands further; verify older data is still rendered (proves archive persistence).
6. Power-cycle the panel and confirm the historical trace reappears (proves the segmented file archive is being read on cold start).

11. Export and Reporting

While WinCC Flexible does not provide a built-in "report designer" with band-style headers, the runtime can export the logged archive to CSV which can be opened in Excel:

1. On the same screen, place an Output field tied to \Storage Card\Logs\ProcessArchive_1s.csv.
2. Add a button with the event: StopRuntime is not required — instead use the TraceExport function or the SmartClient viewer.
3. Use Internet Explorer / browser view control on Comfort Panels to display index.htm served by an SMB share.

For structured shift/daily/weekly/monthly PDFs, the conventional path is to log everything into the archive on the HMI, then use WinCC Explorer on the engineering station to export the archive to a CSV/Excel pivot table. See the HMI report and archive FAQ from Siemens.

12. Troubleshooting Matrix

13. Migration Path to TIA Portal

If the project is later converted with the WinCC Flexible → TIA Portal migrator:

• Archives are converted to Logging DBs (SQLite on Comfort Panels).
• Trend Views map to Trend Control (Compact) / (Advanced) with the same Time base property.
• VBScript code migrates largely unchanged; SmartTags becomes SmartTags/Tags with HMI_Tag namespace.
• The runtime licence "Logging Tags" must be re-counted; confirm with the TIA Portal WinCC Comfort/Advanced manual.

End of life for WinCC Flexible 2008 SP5 is documented under Siemens product support entry 109751463; design new code so it remains migratable.

14. FAQ