Resolving TIA Portal V11 Project Size Growth: PEData.plf Cleanup

Projects in TIA Portal V11 SP2 Update 2 can balloon to several gigabytes when the internal PEData.plf file in the project system folder grows without bound. This article documents the root cause, the affected versions, the safe cleanup paths, and a permanent remediation workflow that includes the V11 → V12 migration route for projects exceeding 2 GB on disk.

1. Problem Description

Engineers running medium-to-large HMI/SCADA configurations (typically one or more Comfort Panels, TP/MP panels, or WinCC Runtime Advanced targets) observe that the .ap11 / .ap11_2 project file system occupies progressively more disk space between saves. Field reports show a project with a single S7-300 station and a TP900 HMI reaching 2.65 GB on disk, with the growth isolated to a single artifact:

<project_root>\System\PEData.plf

For reference, a comparable S7-314C-2DP station with a TP900 HMI in the same product family normally produces a PEData.plf of 10–15 MB. Anything beyond 100 MB warrants investigation, and growth past 1 GB indicates an HMI archive or temporary-data leak.

2. Symptoms

• Project folder size increases on every Save / Save As / Compile operation.
• Project open time grows linearly with the file size (multi-minute open on SSD for > 2 GB).
• TIA Portal reports the project size in the project properties, but the on-disk size remains larger because of unaccounted temporary and archive files.
• Backup and source-control operations (e.g., Git LFS, SVN, TFS) become slow or fail because the diff is dominated by a single binary blob.

You can confirm the project size from the TIA Portal UI via the project properties. The Displaying properties of the project page in the official TIA Portal documentation describes the location of the dialog and the fields shown: creation time, author, file path, project size on disk, copyright, and configured project languages. Note that this is a reference page for V20, but the same menu path (Project → Properties → Project information) applies to V11.

3. Root Cause Analysis

The PEData.plf file is a packed project data store used by the TIA Portal engineering framework. In V11, three primary leak sources feed it:

3.1 HMI Tag Logging and Alarm Logging Archives

When the project contains a WinCC Runtime Advanced / Comfort Panel / WinCC RT Professional target with configured Tag Logging or Alarm Logging, runtime data is written to disk-backed archives under:

<project_path>\IM\HMI\{11866113-2129}\D\<HMI_target_name>\ArchiveManager\

The GUID {11866113-2129} is the internal component identifier for the HMI RT archive manager in V11. In simulation mode (WinCC RT Advanced / PLCSIM HMI), the RT kernel writes log segments to this directory even when no runtime is active, because the project navigator always materializes a default archive structure. Over weeks of development, segments accumulate; PEData.plf consolidates them on every save.

3.2 TMP Folder Accumulation

Uncommitted edit buffers, undo history, and intermediate compile outputs are kept in:

<project_root>\TMP\

Unlike V5.5 (where the project was a flat DB and a periodic reorganization was exposed in the UI), V11 stores a deep folder structure and never prunes the TMP contents automatically. A 6-month project can accumulate 500 MB to 1.5 GB of stale buffer data.

3.3 Converted V10.5 Backups

Projects upgraded from STEP 7 / TIA Portal V10.5 to V11 retain a backup of the pre-conversion state at:

<project_root>\System\Backup\

This is by design — Siemens preserves the V10.5 source for round-trip migration. The backup is rarely needed after the first week of V11 work, but it is not deleted automatically.

3.4 Path Comparison: V5.5 vs V11

4. Diagnosis Procedure

1. Close the project in TIA Portal V11.
2. Right-click the project root in Windows Explorer and select Properties; record the folder size.
3. Open a command prompt in the project root and run the standard size-sweep:

   dir /s /a "PEData.plf" "System\Backup" "TMP" "IM\HMI"

   Note the largest contributors.
4. Verify PEData.plf is > 100 MB and is the dominant file. If it is, the HMI archive leak (Section 3.1) is the primary cause.
5. Inspect the HMI Archive Manager subdirectory: Project tree → HMI target → Historical data → Archives in TIA Portal; confirm that Tag Logging or Alarm Logging is enabled.

5. Resolution

Apply the steps below in order. Each step is independent; stop when the project size is acceptable.

5.1 Step 1 — Clear the TMP Folder (Safe)

The TMP folder is a write-cache; its contents are not referenced after the project is closed. Deleting them is non-destructive.

1. Close the project in TIA Portal.
2. In Windows Explorer, navigate to <project_root>\TMP\.
3. Select all contents (Ctrl+A) and delete. Do not delete the TMP folder itself; TIA Portal recreates it on next open.
4. Reopen the project to confirm no data loss and that compile is clean.

5.2 Step 2 — Delete the V10.5 Predecessor Backup (If Applicable)

1. Close the project.
2. Navigate to <project_root>\System\Backup\.
3. Delete the contents. The V10.5 representation is no longer needed once the V11 project has been validated. Make a separate ZIP archive of the folder if round-trip to V10.5 is a documented requirement.

5.3 Step 3 — Purge HMI Archive Manager Data

1. Close the project.
2. Navigate to <project_root>\IM\ and delete the contents (not the IM folder itself).
3. Reopen the project. TIA Portal rebuilds the HMI archive skeleton; tag/alarm logging configuration is preserved in the project database and re-emitted under IM\HMI\... on next save.

5.4 Step 4 — Re-Archive the Project (V11-Native Equivalent of Reorganize)

V11 does not expose a V5.5-style Reorganize command, but the project can be compacted by archiving and retrieving:

1. With the project open in TIA Portal V11, select the project name in the project tree.
2. Choose Project → Archive. Save the .zap11 archive to a new location.
3. Close the project.
4. Choose Project → Retrieve and select the .zap11. Save to a fresh directory.
5. Open the retrieved project and verify functionality (compile, online, download to PLCSIM).

Typical compaction ratio is 30–60% on a project that has not been re-archived since the last major HMI configuration change.

5.5 Step 5 — Migrate to TIA Portal V12 (Recommended Permanent Fix)

The V11 archive code is known to be less efficient than the V12 engine. V12 also introduces changes to the PEData.plf packing algorithm that prevent the runaway growth observed in V11 SP2. The migration is the strongest long-term remediation.

1. Install TIA Portal V12 (V12 SP1 recommended for the stability fixes). Both V11 and V12 can coexist on the same workstation.
2. Open the V11 project in V12. V12 will offer an upgrade; accept it. The original V11 .ap11 is preserved by the upgrade wizard.
3. Select the project root in the project tree.
4. Choose Project → Archive to create a V12 .zap12.
5. Close the project, then Project → Retrieve the archive into a new directory.
6. Open the retrieved project. Observe that PEData.plf is now typically < 5% of its pre-migration size.

6. Verification

After each cleanup step, validate the project with the following sequence:

1. Compile: Project tree → PLC/HMI → Compile → Software (rebuild all). No errors should appear that were not present before the cleanup.
2. Consistency check: Right-click the device → Compile → Check consistency. Cross-reference any HMI tag references that the rebuild may have re-bound.
3. Download to PLCSIM: Start S7-PLCSIM and the HMI RT. Confirm that all configured tag and alarm logs begin recording from a clean baseline.
4. Size check: Repeat the Section 4 diagnosis. The new PEData.plf size should be reported via the project properties dialog and via Windows Explorer.
5. Source control: Commit the compacted project to the version-control system. The diff should now consist of legitimate project edits, not bulk PEData.plf churn.

7. Prevention

Add the following operational practices to the project workflow to prevent recurrence:

• Configure HMI Tag Logging and Alarm Logging to write to an external runtime path (e.g., a USB stick on the panel or a network share on RT Advanced) rather than the project folder. Disable Backing up tags/alarms on engineering station where it is not needed.
• Schedule a monthly re-archive of the project (Section 5.4) and check in the compacted copy to source control.
• When porting from V10.5, delete the System\Backup folder once the V11 build is accepted by QA.
• Add a CI check that fails any merge request if PEData.plf exceeds a configured threshold (for example, 50 MB for a project of known size).
• Where supported by the panel firmware (Comfort Panels V14 and later, WinCC Unified), migrate to a TIA Portal version that ships the revised PEData.plf packer (V12 SP1 or later).

8. Troubleshooting Matrix

9. Field-Proven Caveats

• Always make a full backup of <project_root> before any of the cleanups in Section 5. The PEData.plf is a packed binary; manual corruption is not repairable by TIA Portal.
• Do not run the cleanup while TIA Portal or an S7-PLCSIM instance has the project open. The TMP and IM folders are held with shared locks during the engineering session.
• The ArchiveManager path uses the GUID {11866113-2129} in V11; V12 and later use a different GUID. If you are migrating, the old GUID directory is not migrated and is safe to delete after the V12 retrieve.
• If your project uses WinCC RT Professional (PC-based, not panel-based), the archive root is typically redirected to a project-path subfolder via the Computer → Archive Manager settings; verify the path before deleting anything under IM.
• Source-control systems that store the entire .ap11 as a single artifact will see large diffs even after compaction. Consider LFS (Git) or Perforce for binary blob storage.

10. Related Project Properties to Monitor

The TIA Portal Project → Properties dialog (described in the Displaying properties of the project documentation) shows the on-disk project size and is the fastest way to track growth between saves. Combine the on-disk size reading with a Windows-level dir /s sweep to identify which subfolder (System, IM, TMP) is dominant in the current project state.