Troubleshoot PCS 7 OS Compile Error 302:309 When Server Data Is Missing

An OS(302:309) compile error cannot be diagnosed from the code alone when the full message and load log are unavailable. If the OS client also lacks a required server-data package, verify the client/server configuration and package generation and assignment. PCS 7 V9.1 documents automatic package generation during OS compilation/download and a manual Generate server data command, but the discussion does not establish that the missing package caused this error.

What is known about OS(302:309)

The discussion reports an OS compilation error identified as OS(302:309) and says no server-data package is visible in WinCC Explorer. It does not include the full compiler message, load log, software versions, project architecture, or a confirmed fix. The error code alone is not enough here to identify a root cause.

For a PCS 7 client/server configuration, server data packages are produced from the OS server project and assigned to OS client projects. The PCS 7 V9.1 Compendium describes automatic generation or updating during OS compilation/download and a manual “Generate server data” command in SIMATIC Manager. It also describes assigning the required server data to each client project. These steps are relevant when a required server package is missing; they are not proof that missing server data caused this particular compile error.

Check the client/server configuration

Record the exact PCS 7 and WinCC versions and update levels, the selected OS object, compile mode, complete error text, and OS load/compile log.
Confirm whether the project is single-station, a server/client system, or a redundant server pair. Verify that the OS object and target are the intended ones.
In SIMATIC Manager, verify the configured AS-OS assignment and S7 connection for the applicable OS project. Confirm the PC station configuration matches the intended computer and project path.
If the client requires server data, inspect the server project's data and check whether packages exist. In PCS 7 V9.1, the Compendium says OS compilation/download generates or updates server data; it also documents the manual “Generate server data” command in SIMATIC Manager.
Assign the required server data to each OS client project using the release-specific “Assign OS Server…” procedure. Verify the assigned package appears under Server data in the client project.
Recompile the intended OS object and review the full diagnostics. Do not assume that generating a package has corrected OS(302:309) unless the compile log confirms it.
If the error persists, stop and diagnose from the complete load log and project configuration rather than applying unverified database, service, or folder changes.

How to interpret missing server data

A client that is meant to display process information from an OS server needs that server's data package assigned. In PCS 7 V9.1, the package can be updated automatically with OS compilation/download, and the Compendium describes manual server-data generation as an alternative. If no package is visible, first establish whether the selected object is the server project or client project; package generation and assignment occur on different objects.

The discussion does not say whether this was a new or existing project or which topology was configured. An absent package may therefore be a configuration symptom, but it cannot be linked conclusively to the OS(302:309) error based on this report.

Verification

Confirm that the generated package is present on the server project and that the intended package is assigned to the client. Check the client project's Server data view after assignment. Recompile and verify the actual OS(302:309) diagnostic is cleared; then inspect the OS compile/download log for remaining warnings or errors. For a redundant configuration, verify package generation and assignment for the intended server pair and test the client/server data path according to the applicable PCS 7 procedure.

Limitations and Operational Precautions

Only a short split discussion is available. It does not include the original thread's screenshots, exact error text, versions, project type, network configuration, or logs, and it has no confirmed resolution. The response's setup checklist is useful as an initial review, but not a proven cause or fix. Do not restart SQL services, delete databases, or alter project folders based on generic advice without Siemens documentation for the specific diagnostic and a complete backup.

Engineer FAQ

Does OS(302:309) identify a missing server-data package? The available source does not establish that relationship. It reports both an OS compile error and a missing package, but provides no compiler details or confirmed resolution.

How are PCS 7 server-data packages generated? PCS 7 V9.1 documentation says they are generated or updated during OS compilation/download; SIMATIC Manager also provides a manual “Generate server data” action.

Where should an OS client receive server data? Assign the required server data to the OS client project using the release-specific “Assign OS Server…” function, then verify the package under Server data.

What should be checked before compiling? Verify the intended OS object, AS-OS assignment, S7 connection, PC station configuration, server/client topology, and current project path.

Should I delete or recreate the project directory if compilation fails? No such recovery is supported by this discussion. Preserve the project and diagnose from the full error and load log before modifying project files.

Technical References

Siemens, PCS 7 Compendium Part A – Configuration Guidelines (V9.1), 03/2022, section 10.1.1, pp. 210–213. It describes generation/updating of OS server data and assignment of packages to OS client projects: PDF.
Siemens, SIMATIC PCS 7 Operator Station (V9.1 SP1) Configuration Manual, 11/2021, sections 6.1 and 6.4, for OS project setup in SIMATIC Manager: PDF.

Troubleshoot PCS 7 OS Compile Error 302:309 When Server Data Is Missing