Resolving PCS 7 OS Compile Error (302:309) After Multiproject Retrieval and Station Renaming

In SIMATIC PCS 7, error OS Compile (302:309) encountered after retrieving a multiproject onto a different Engineering Station occurs because the OS project's internal database still references the original computer name, or because Simatic Shell network adapter bindings are misaligned. Before compiling the OS on a new PC, the SIMATIC PC Station name in SIMATIC Manager must match the local Windows computer name, the Simatic Shell Terminal Bus adapter must be set to the active network interface, and outdated Data Communication Files (*.dcf) must be cleared. Delta compilation is not permitted until an initial complete compilation succeeds.

Executive Summary

When commissioning engineers transfer or retrieve a SIMATIC PCS 7 multiproject from a development PC to a site Engineering Station (ES) or combined ES/OS station, compiling the Operator Station frequently aborts with error code OS Compile (302:309). This error typically halts the compilation process during server data creation or tag generation. The root cause is a mismatch between the computer name recorded in the WinCC project database (.mcp), the SIMATIC PC Station object name in Step 7, and the local Windows host name, compounded by obsolete communication cache files. This guide outlines the prerequisite configuration sequence required to adapt retrieved multiprojects and eliminate error 302:309.

Architecture and Fundamental Mechanics

The PCS 7 OS compilation engine integrates Step 7 engineering data with Microsoft SQL Server through several dependent interfaces:
1. Computer Name Binding:
WinCC projects store the authoring computer name in the project configuration database (<ProjectName>.mcp). When the OS compiler runs from SIMATIC Manager, it verifies that the local Windows computer name matches the computer name declared in the WinCC project properties. If they diverge, WinCC rejects database attachment or refuses to spawn package generation processes.
2. SIMATIC PC Station Alignment:
In SIMATIC Manager, each OS resides inside a SIMATIC PC Station. The PC Station object name must match the physical computer name configured in the Station Configuration Editor (Station Manager). If the retrieved project retains the original engineering laptop's name, the OS compiler cannot resolve the local communication endpoints.
3. Simatic Shell Terminal Bus Binding:
The OS compilation process invokes internal Remote Procedure Calls (RPC) across the Simatic Shell layer. If Simatic Shell is bound to an inactive virtual adapter (such as a disabled VPN or secondary NIC) rather than the active Terminal Bus adapter, internal inter-process handshakes time out, triggering error 302:309.

Step-by-Step Implementation Procedure

Verify Local Windows Hostname and PC Station Name:
a. On the Engineering Station, open Windows Settings or execute hostname in PowerShell to confirm the exact Windows computer name.
b. Open the retrieved multiproject in SIMATIC Manager.
c. Locate the SIMATIC PC Station containing the OS object. If its name differs from the Windows hostname, right-click the PC Station, select 'Rename', and enter the exact Windows computer name.
Update Computer Name in WinCC Explorer:
a. Right-click the OS object in SIMATIC Manager and select 'Open Object' to launch WinCC Explorer.
b. In WinCC Explorer, expand the left navigation tree, select 'Computer', right-click the listed computer in the right pane, and select 'Properties'.
c. Click 'Use Local Computer Name'.
d. Close WinCC Explorer and restart the PC if prompted.
Bind Simatic Shell to the Active Terminal Bus Adapter:
a. Open Windows File Explorer and click on 'Simatic Shell'.
b. Right-click 'Simatic Shell' and select 'Settings...'.
c. Select the physical network adapter connected to the Terminal Bus (highlighted with an IP address).
d. Confirm encryption settings match plant standards and click OK to restart Simatic Shell communication.
Clear Obsolete Communication Cache Files (*.dcf):
a. Ensure WinCC Explorer and SIMATIC Manager are closed.
b. Open Windows File Explorer and navigate to the OS project directory (e.g., <ProjectPath>\wincproj\<OSName>\).
c. Locate and delete all files with the extension .dcf (e.g., <OSName>.dcf). These cache files will be regenerated automatically during the next compilation.
Execute Complete OS Compilation:
a. Reopen SIMATIC Manager.
b. Right-click the OS object and select Compile.
c. In the compilation wizard, ensure 'Entire OS' is selected instead of 'Changes'.
d. Proceed with the compile: verify that server data generation and tag creation complete with 0 errors.

Verification

Monitor the OS Compile progress dialog: verify that the compilation passes through 'Tag Management', 'Alarm Logging', and 'Creating server data' without interruption.
In the OS compilation log window, confirm status: 0 Errors, 0 Warnings.
Open WinCC Explorer: verify that the project opens immediately without prompting to convert or rename the database.
Check the Server Data branch in WinCC Explorer: verify that the generated package (.pck) displays the current timestamp.

Limitations and Operational Precautions

Changing computer names or deleting .dcf files invalidates previous delta-download baselines. The first OS download following this procedure must be executed as an 'Entire WinCC Project' download rather than a delta download.

Engineer FAQ

What causes OS Compile error 302:309 on a newly retrieved project?

It is primarily caused by mismatched computer names between Windows and the WinCC project, corrupted .dcf cache files, or incorrect Simatic Shell network adapter selection.

Can I compile the OS without renaming the SIMATIC PC Station?

No. The SIMATIC PC Station name in SIMATIC Manager must match the physical Windows computer name where the compilation is executed.

Is it safe to delete .dcf files from the WinCC project folder?

Yes. Files with the .dcf extension are temporary data communication caches that WinCC automatically regenerates upon opening or compiling.

Why did 'Changes only' compile fail after project retrieval?

A retrieved project on a new computer has no valid baseline comparison with the previous compile; an initial 'Entire OS' compile is strictly required.