Preserving Historical Tag Logging Archives When Moving Plant Hierarchy Folders

Moving a Plant Hierarchy (TH) folder containing archived measuring points does not destroy historical Tag Logging data if 'Included in the tag name' is disabled in Plant Hierarchy Settings. In that standard configuration, archive tag names and their internal SQL database IDs remain based solely on chart and block pin names; the modification date and internal ID in Tag Logging do not change upon OS compilation, preserving continuous historical trend curves. However, if 'Included in the tag name' is enabled, moving the folder alters the tag's fully qualified path, prompting WinCC to create a new archive tag and stranding historical records under the retired tag name.

Plant Hierarchy Naming Rules and WinCC Archive Tag Identity

In SIMATIC PCS 7, the Plant Hierarchy (TH) organizes charts, pictures, and reports into technological plant areas. When an analog measuring point (such as MonAnL) is configured with the archive attribute, the OS compiler creates an archive tag inside WinCC Tag Logging and maps it into the historical Microsoft SQL Server database (<ProjectName>#<ArchiveName>).

The naming convention of this archive variable depends on a global setting configured in SIMATIC Manager:

Path Not Included in Tag Name: The WinCC variable name consists strictly of the CFC chart name and the block output pin (e.g. XX17BTSR/PV_Out#Value).
Path Included in Tag Name: The WinCC variable name prepends the full technological folder path (e.g. Plant/ZLT/Building17/XX17BTSR/PV_Out#Value).

Understanding which mode is active is critical when reorganizing plant folders (e.g. moving Building 17 from area ZLT to area Microbiology to adjust operator authorization levels).

Impact of Moving Folders on Tag Logging SQL Databases

When a hierarchy folder is moved within SIMATIC Manager:

Case A (Path Excluded - Standard): Because the tag name does not contain the folder names, its string identity is unaltered. During the subsequent delta OS Compile, the compiler compares the offline ES tags against the WinCC database, finds an exact name match, and leaves the internal archive record and its SQL identifier (ArchiveTagID) intact. Existing runtime trends and historical curve groups continue logging and displaying historical data seamlessly.
Case B (Path Included): Because the folder relocated, the fully qualified tag path changes (e.g. from .../ZLT/... to .../Microbiology/...). During OS Compile, WinCC considers the old tag deleted and generates a brand-new archive tag with a new internal SQL ID. While existing archive segments containing historical data under the old ID are not physically deleted from disk, runtime trend controls configured to follow the new tag name will only display data starting from the compilation timestamp forward.

Pre-Move Verification Procedure in Plant Hierarchy Settings

Before reorganizing hierarchy folders in a live or commissioned plant, execute this verification procedure:

Inspect Plant Hierarchy Settings:
- In SIMATIC Manager, select the plant hierarchy root folder.
- Navigate to Options -> Plant Hierarchy -> Settings....
- Inspect the checkbox: Included in the tag name (Im Namen von Variablen / Bausteinen enthalten).
- If this checkbox is unchecked, moving folders will not rename tags or disrupt SQL archives.
Validate in a Project Copy:
- Save a backup copy of the project.
- Move the target folder in the copy.
- Run a delta OS Compile.
- Open WinCC Explorer -> Tag Logging in the copy.
- Inspect the Modification Date (Änderungsdatum) and properties of the archive tag. If the date and ID are unchanged, the move is safe.
Adjust User Authorizations: If moving the folder was done solely to change operator access rights, configure the new area rights in WinCC User Administrator, ensuring operators in the new area have appropriate viewing permissions.

Plant Hierarchy Tag Naming Options and Archive Impact Matrix

The following table summarizes the impact of moving hierarchy folders based on project configuration settings:

Setting in Plant HierarchyTag Name StructureMoving Folder Changes Tag Name?WinCC SQL Archive Tag IDHistorical Trend Curve ContinuityIncluded in Tag Name: UNCHECKED<ChartName>/<Block>.<Pin>No (Remains identical)Retained (Unchanged)Fully preserved; seamless historyIncluded in Tag Name: CHECKED<Area>/<Unit>/<ChartName>/<Block>.<Pin>Yes (Renamed)New ID generatedHistory split; old data stranded under old IDPicture Tree HierarchyGraphic PDL containerMoves container in treeN/ASplit Screen navigation updates automaticallyArea-Based Alarm FilteringTechnological AreaUpdates message area stringMessage ID retainedAlarms route to new area view

[!NOTE]
Commercial Accuracy Notice: Reorganizing Plant Hierarchy containers and adjusting Tag Logging archive associations > are standard engineering operations within SIMATIC PCS 7 (6ES7658-1EX58-0YA5). No additional WinCC archive tag licenses > or Process Objects are consumed when relocating existing measuring points.

Verification

Confirm that historical process data remains continuous after relocating the folder:

Tag Logging Inspection: After delta OS Compile, open WinCC Tag Logging on the OS. Confirm that the target process variable retains its original archive tag name and internal ID.
Runtime Trend Validation: Open WinCC Runtime, navigate to the relocated measuring point faceplate, and select the trend view. Confirm that trend curves display unbroken data spanning before and after the engineering change.
Process Historian Check: If a SIMATIC Process Historian is deployed, verify that archive packets continue to stream to the active segment without generating duplicate tag entries.

Limitations and Operational Precautions

Adhere to these precautions during Plant Hierarchy restructuring:

Avoid Changing Chart Names: Even if 'Included in the tag name' is unchecked, changing the name of the CFC chart itself will alter the tag name and create a new archive variable.
Full OS Compile Hazards: Performing an Entire OS Compile does not erase existing Tag Logging archives, but ensure that the option 'With memory reset' is never selected.
KKS / Measuring Point Consistency: Maintain plant labeling standards (KKS / DIN) when moving technological containers to avoid confusion across operating teams.

Engineer FAQ

Does moving a hierarchy folder erase previously recorded archive data in SQL?

No. Previously recorded archive segments on disk are never deleted by moving a folder. However, if the tag is renamed, runtime trend controls will not link to the historical data recorded under the old tag name.

How can I tell if 'Included in the tag name' is active in my project?

In SIMATIC Manager, go to 'Options -> Plant Hierarchy -> Settings...' and inspect the checkbox 'Included in the tag name'. Alternatively, check if your WinCC tag names contain slash characters representing folder levels.

Can I reconnect old historical data if a tag was renamed during a move?

Yes, but it requires configuring the trend control to display an archive curve pointing to the retired tag name or using SQL migration tools to remap archive IDs.

Does moving a folder change the WinCC user access rights automatically?

Moving a chart to a new technological area assigns the block's WinCC faceplates to that area. Operators whose user accounts lack authorization for that new area will no longer be permitted to operate the block.