Compatibility Rules and Project Migration Between SIMATIC PCS 7 V9.0 and WinCC V7.4

In Siemens industrial automation environments, opening or migrating projects between SIMATIC PCS 7 V9.0 and standalone SIMATIC WinCC V7.4 is governed by strict version mapping and architectural dependency rules. SIMATIC PCS 7 V9.0 delivers and natively integrates SIMATIC WinCC V7.4 SP1 Upd1 (or higher), whereas base WinCC V7.4 (without service packs) corresponds to PCS 7 V8.2. Standalone WinCC and PCS 7 can never be co-installed on the same operating system. Furthermore, while a standalone WinCC V7.4 project can be migrated to V7.4 SP1 and imported into PCS 7 V9.0 via "OS Import", opening a native PCS 7 V9.0 OS project in a standalone WinCC environment is unsupported due to specialized PCS 7 system libraries.

Version Architecture: Integrated WinCC vs Standalone WinCC

A frequent source of engineering confusion is the relationship between standalone SIMATIC WinCC (the general-purpose SCADA software) and the WinCC software component embedded within SIMATIC PCS 7.

Every major release of SIMATIC PCS 7 bundles a specific, tightly tested release of WinCC:

SIMATIC PCS 7 ReleaseIntegrated WinCC Version & Service PackDirect Standalone WinCC Project OpeningPCS 7 V8.1WinCC V7.3 SE (Second Edition)Compatible with standalone WinCC V7.3PCS 7 V8.2WinCC V7.4 (Base Release)Compatible with standalone WinCC V7.4PCS 7 V9.0 (Base Delivery)WinCC V7.4 SP1 Upd1Requires WinCC V7.4 SP1 or project migrationPCS 7 V9.0 SP1WinCC V7.4 SP1 Upd4 / Upd7Requires WinCC V7.4 SP1 with matching updatesPCS 7 V9.1WinCC V7.5 SP2Requires standalone WinCC V7.5 SP2

Because PCS 7 V9.0 integrates WinCC V7.4 SP1, opening a project created in base WinCC V7.4 requires upgrading the project database schema to Service Pack 1.

Co-Installation Restrictions on Engineering Workstations

A critical system rule enforced by the Siemens installation arbiter:
* Standalone WinCC and SIMATIC PCS 7 CANNOT be co-installed on the same physical or virtual operating system.
* The PCS 7 installer replaces standard WinCC setup binaries with customized versions that embed PCS 7 extensions (Basic Process Control, Split Screen Manager, SFC Visualization, and APL faceplate libraries).
* Attempting to install standalone WinCC on a PCS 7 Engineering Station halts with a fatal compatibility block.

Opening Standalone WinCC Projects in PCS 7 V9.0

To bring a project authored in standalone WinCC V7.4 into a PCS 7 V9.0 Engineering Station:

Migrate Project Database to SP1:
- On the PCS 7 V9.0 ES, open the WinCC Project Migrator utility (C:\Program Files (x86)\Siemens\WinCC\bin\CCProjectMigrator.exe).
- Select the standalone WinCC V7.4 project file (.mcp).
- The migrator upgrades the Microsoft SQL Server database schema from V7.4 base to V7.4 SP1.
Import into SIMATIC Manager:
- Open SIMATIC Manager and load the Multiproject.
- Select Options -> OS Import....
- Browse to the migrated .mcp project file and complete the import.
- The standalone project is now an integrated OS inside PCS 7 V9.0.

Why Native PCS 7 OS Projects Cannot Open in Standalone WinCC

Attempting the reverse—copying a native PCS 7 V9.0 OS project folder to a standalone WinCC V7.4 computer and attempting to open it in WinCC Explorer—results in immediate startup failure:
1. Missing PCS 7 Option Packages: A native PCS 7 OS project requires libraries including BPC (Basic Process Control), SSM (Split Screen Manager), and SFC Visualization. If opened on standalone WinCC lacking these options, WinCC Explorer displays: "The project contains components that are not installed on this computer."
2. Version Mismatch: Base WinCC V7.4 cannot read a database created or migrated by WinCC V7.4 SP1.
3. Database Lock: PCS 7 OS projects link their tag dictionaries to the STEP 7 engineering database (ombstx). Opening the OS outside of SIMATIC Manager severs these bindings.

Verification

To verify software compatibility and project migration status:
1. In WinCC Explorer on the PCS 7 V9.0 station, select Help -> About WinCC; confirm the version reads SIMATIC WinCC V7.4 SP1 Upd1 (or higher).
2. Open the imported WinCC project; confirm that WinCC Explorer loads the project tree without database version errors.
3. In Graphics Designer, open process pictures; confirm that all graphic objects and scripts compile cleanly.
4. Activate WinCC Runtime; confirm that process graphics display without licensing or component error dialogs.

Limitations and Operational Precautions

Never open a native PCS 7 OS project directly from the Windows file system using standalone WinCC Explorer without launching SIMATIC Manager first. Bypassing SIMATIC Manager can desynchronize the WinCC tag dictionary from the CFC charts, resulting in broken interconnections during subsequent OS compilations. Always manage PCS 7 OS projects through SIMATIC Manager.

Engineer FAQ

Can a project created in PCS 7 V9.0 be opened in PCS 7 V8.2?

No. PCS 7 projects are not backward-compatible. A project migrated or created in PCS 7 V9.0 cannot be opened in PCS 7 V8.2.

What tool updates an older WinCC project to match PCS 7 V9.0?

The WinCC Project Migrator tool converts database schemas from older WinCC versions to the currently installed version.

Does a standalone WinCC license work for PCS 7 OS Runtime?

While both use Automation License Manager, PCS 7 OS Runtime packages bundle specific Process Object (PO) licensing and Basic Process Control options that standard WinCC licenses do not include.