Resolving Blank Plant Hierarchy Folder Names and Database Disconnects in PCS 7 Engineering Stations

In SIMATIC Manager on a PCS 7 Engineering Station (ES), plant hierarchy (PH) folders appearing completely blank (with missing folder text and inaccessible CFC charts) is caused by a broken inter-process socket connection between the STEP 7 GUI and the underlying engineering Sybase/SQL database. This condition frequently occurs in virtualized environments when a virtual machine (VMware or Hyper-V) is paused, suspended, or resumed while a PCS 7 project is open, which abruptly severs active TCP/pipe connections to the database engine. It can also stem from database lock contention during multi-user engineering or corrupted index files. To resolve the issue, close SIMATIC Manager cleanly, verify that all background Sybase processes (dbeng*.exe) have terminated, reopen the project, and perform 'Save As... With Reorganization (slow)' to rebuild the plant hierarchy index.

Executive Summary

The Plant Hierarchy (PH) serves as the foundational architectural backbone of any SIMATIC PCS 7 project, structuring automation assets into plant sections, units, and equipment phases. A disruptive glitch occurs when an engineer navigates the project tree and discovers that one or more hierarchy folders display blank titles, completely hiding contained CFC charts, SFCs, and OS pictures. Attempting to insert new charts or edit existing logic fails. Because the plant hierarchy metadata is governed by a dedicated embedded relational database, any interruption—most commonly pausing a virtual machine, network share latency, or sudden user session suspension—causes the GUI to lose its database cursor. Rebuilding the database indices via reorganization and adhering to virtualization best practices permanently resolves the issue.

Architecture and Fundamental Mechanics

The SIMATIC PCS 7 Plant Hierarchy is managed by an integrated technological database engine operating beneath the standard STEP 7 file system:

The Plant Hierarchy Database Structure:
* In PCS 7, the plant hierarchy structure is not merely a collection of Windows directories; it is governed by an embedded Sybase Adaptive Server Anywhere (ASA) / SQL database (p_plant.db or amdbase.db) located within the project's Global and s7bin folders.
* The database engine (dbeng*.exe or dbsrv*.exe) maintains live TCP loopback sockets and memory-mapped file handles with SIMATIC Manager components (s7tgtopx.exe, s7wzwd.exe).
The Impact of Virtual Machine Suspend/Resume:
* Siemens technical documentation explicitly prohibits pausing or suspending a virtual machine hosting an active PCS 7 Engineering Station.
* When a hypervisor (e.g., VMware Workstation, ESXi) suspends a VM, the virtual hardware clock halts and all open network sockets and internal Windows IPC pipes freeze.
* Upon resumption, the database engine detects a heartbeat timeout or socket reset. The database engine drops the active client session, while SIMATIC Manager remains unaware that the connection handle is stale.
* When SIMATIC Manager attempts to query folder names, block icons, or hierarchy levels, the database query returns NULL. The GUI renders the folder icon without text (blank folder name), and all child objects become inaccessible.
Database Fragmentation and Index Corruption:
* In large multiprojects subject to frequent chart insertions, deletions, and type updates, the internal B-tree indices of amdbase.db can become fragmented. If an index pointer corrupts, specific hierarchy queries fail silently, resulting in blank nodes.

Step-by-Step Implementation Procedure

Follow these procedures to recover from blank hierarchy folder names and prevent recurrence:

Cleanly Restart SIMATIC Manager and Database Services:
* Close SIMATIC Manager cleanly (File > Exit). If prompted to save, select No to avoid committing partially loaded states.
* Open Windows Task Manager (Ctrl + Shift + Esc) and navigate to the Details tab.
* Inspect active processes. Ensure that neither s7tgtopx.exe nor any Sybase database engine processes (e.g., dbeng9.exe, dbeng12.exe, dbsrv*.exe) remain running.
* If hung database processes remain, terminate them manually or reboot the Windows workstation.
Reopen and Inspect the Multiproject:
* Launch SIMATIC Manager.
* Open the multiproject and navigate to the Plant View (View > Plant View).
* Verify whether the folder names reappear correctly.
Execute 'Save As... With Reorganization (Slow)':
* In SIMATIC Manager, select File > 'Save As...'.
* Choose a new project name or path.
* Check the radio button With reorganization (slow).
* Click OK. SIMATIC Manager will perform a block-by-block and table-by-table read of the entire project, purging unreferenced objects, rebuilding internal database B-trees, and re-indexing the plant hierarchy tables.
* Depending on project size, this process may take from 5 to 30 minutes.
Enforce Virtualization Operational Rules:
* Inform all engineering personnel that pausing or suspending VMs while PCS 7 is running is strictly prohibited.
* Always perform a clean File > Exit in SIMATIC Manager and close all WinCC / CFC editors before shutting down, snapshotting, or migrating a VM.
* If taking hypervisor snapshots, ensure the VM is powered off or that memory snapshots are avoided during active engineering sessions.
Run the Siemens Assessment Suite (If Issue Persists):
* If blank folder names recur without VM suspension, download and run the SIMATIC Assessment Suite - Data Collector (SASDC).
* Collect system logs, event viewer records, and STEP 7 diagnostic traces, and submit a Support Request (SR) to Siemens Industry Online Support.

Verification

After performing reorganization, open the project in SIMATIC Manager. Expand all plant hierarchy levels in the Plant View; confirm that every folder displays its complete, alphanumeric title without blank entries. Right-click a folder and verify that Insert New Object > CFC is active and functional. Open existing CFC charts within the formerly blank folders and confirm that all block connections and hierarchy paths resolve cleanly.

Limitations and Operational Precautions

Never manually delete or rename files inside the project folder (*.db, *.log, *.dbf) using Windows File Explorer. Doing so breaks transaction log synchronization and will result in unrecoverable project database corruption. Always use SIMATIC Manager's built-in reorganization and archiving utilities.

Engineer FAQ

Why does pausing a VMware virtual machine corrupt the PCS 7 display?

Pausing a VM freezes internal TCP sockets and Windows named pipes. When resumed, the Sybase database engine drops the stale socket connection, preventing SIMATIC Manager from querying folder metadata.

What does 'Save As... With Reorganization (slow)' actually do?

It copies all valid project records into a brand-new database file structure, eliminating empty database gaps, purging deleted objects, and completely reconstructing all indices.

Can multi-user engineering cause blank hierarchy folders?

Yes. If network latency between the ES client and the centralized server causes a database query timeout, the GUI may fail to load folder attributes.

Is this issue related to PCS 7 software version compatibility?

No. It is an infrastructure and database communication issue that can occur on any version of PCS 7 (V7.x through V9.1) if virtualization rules are violated.