Resolving Grayed-Out Alarm Logging Archive Settings and Computer Name Mismatch in WinCC 7.3 / PCS 7

In WinCC v7.3 and SIMATIC PCS 7, Alarm Logging archive configuration settings appear grayed out on the Engineering Station when the configured WinCC Station Computer Name does not match the actual Windows hostname of the local PC. While Tag Logging allows certain global edits, WinCC locks Alarm Logging archive parameters to prevent multi-station configuration conflicts. To resolve this issue, open WinCC Explorer, navigate to Computer Properties, click 'Use Local Computer Name', restart WinCC Explorer, and verify that the Engineering Station holds the appropriate basic archive and OS engineering licenses.

Root Cause of Disabled Alarm Logging Archive Parameters

When engineering an Operator Station (OS) project in SIMATIC PCS 7 or standalone SIMATIC WinCC v7.3, opening the Alarm Logging editor occasionally reveals that the entire Archive Configuration context menu (including archive size, time period, and segmentation limits) is inactive or grayed out. Meanwhile, the Tag Logging editor on the same station permits full access to fast and slow tag archive parameters.

This asymmetrical lockout occurs because the WinCC runtime database engine distinguishes between global engineering settings and host-specific runtime archive parameters:
* Host Identity Binding: Alarm Logging archive segmentation settings dictate Microsoft SQL Server transaction log allocations, disk rollover triggers, and database attachment scripts on the specific physical computer designated to host the runtime.
* Client / Remote Lockout Mode: If the local PC's Windows hostname (e.g., ES_ENG_01) differs from the computer name registered in the WinCC project properties (e.g., OS_SRV_01), WinCC Explorer operates in restricted client/remote configuration mode, disabling local alarm archive properties to prevent accidental database schema mismatches.

Computer Name Property Synchronization vs Station Lockout

The following matrix compares station identity attributes and their effects on WinCC project configuration:

Configuration SettingWinCC Property LocationLocal Match Required?Impact if MismatchedWinCC Computer NameWinCC Explorer > Computer PropertiesYesAlarm Logging archive properties disabled; runtime startup blocked.OS Server Target PathSIMATIC Manager > OS PropertiesYes (for download)OS Compile and Download fails with UNC path resolution error.Tag Logging ArchiveTag Logging Editor > ArchivesPartialGlobal tag archiving definitions viewable; local storage paths locked.Alarm Logging ArchiveAlarm Logging > Archive ConfigurationYesArchive properties completely grayed out; unable to configure segment size.SIMATIC Shell StationWindows Explorer > SIMATIC ShellYesTerminal bus heartbeat lost; redundancy partner synchronization fails.

Table 1: Station name configuration dependencies across WinCC and PCS 7 engineering tools.

Step-by-Step Procedure to Unlock Alarm Logging Configuration

To unlock the Alarm Logging archive configuration on an Engineering Station or transferred OS project:

Verify Host Windows Computer Name:
* Open Windows Command Prompt and run hostname, or open System Properties to verify the exact computer name (e.g., ES_STATION_A).
Synchronize WinCC Computer Name:
* Open the OS project in SIMATIC WinCC Explorer.
* In the navigation tree, click on the Computer icon.
* Right-click the computer object listed in the right pane and select Properties.
* On the General tab, observe the field Computer Name. If it reflects a remote server name or old host name, click the Use Local Computer Name button.
* Click OK to apply the change.
Restart WinCC Database Engine:
* Close WinCC Explorer completely.
* If background database locks persist, open Command Prompt as Administrator and execute Reset_WinCC.vbs.
* Reopen the project in WinCC Explorer.
Access Archive Configuration:
* Open Alarm Logging.
* Right-click Archive Configuration > Message Archive and select Properties.
* Confirm that all parameters (Maximum size of all segments, Time period of all segments, Maximum size of a single segment) are now active and fully editable.

WinCC Archive Licensing and Engineering Station Constraints

In SIMATIC PCS 7, runtime message archiving is governed by Process Objects (PO) and WinCC Archive licensing:
* Basic Licensing: PCS 7 OS Single Station and OS Server software packages (e.g., 6ES7652-0XX08-1XB0) include baseline message archiving and 512 archive tags for process values without requiring separate add-on licenses.
* Archive Tag Expansion: Expanding process value tag logging beyond 512 tags requires WinCC Archive Tag upgrade packages (6AV6371-1DQ17-3AX0 or equivalent SIMATIC PCS 7 OS RT PO upgrades). However, alarm message archiving itself does not consume archive tag licenses; it is bounded by SQL Server disk quotas and OS Server hardware sizing rules. Always validate license packages and MLFBs with an authorized Siemens distributor.

Verification

To confirm proper resolution:

In WinCC Explorer, verify that the Computer Name listed under Computer matches the local hostname returned by Windows hostname.
Open Alarm Logging, right-click Archive Configuration > Message Archive, and select Properties.
Confirm that all numeric fields and dropdowns under Archive Configuration are editable.
Modify a test parameter (e.g., set maximum segment size to 500 MB), click OK, and reopen the dialog to confirm the value persists.
In SIMATIC Manager, perform an OS Compile (Changes Only) and verify zero database synchronization warnings.

Limitations and Operational Precautions

When engineering an OS project destined for a redundant OS Server pair (6ES7652-0XX08-1XB0), never leave the Engineering Station hostname permanently assigned to the OS Server object; before downloading to the plant, ensure the Target OS Path and Computer Name in SIMATIC Manager match the physical OS server.
After changing the computer name in WinCC Explorer, always execute a clean project download from the ES rather than copying project files manually via Windows Explorer.
Avoid using special characters, underscores, or names exceeding 15 characters for Windows hostnames in PCS 7 environments.

Engineer FAQ

Why did Tag Logging remain editable while Alarm Logging was grayed out?

Tag Logging stores process tag definitions in design tables that allow offline engineering regardless of host identity. Alarm Logging archive configuration directly binds to runtime SQL Server partition scripts, which WinCC restricts to the matching local computer name.

Does clicking 'Use Local Computer Name' break multi-station projects?

On an Engineering Station, using local computer name allows local configuration and testing. However, for a distributed OS Server, the proper workflow is to maintain the target server name in SIMATIC Manager and perform an OS Download to deploy the project with the server's identity.

Can archive settings be modified while WinCC Runtime is active?

Certain archive parameters can be adjusted during runtime on the server, but changes to segment size and path locations only take effect after archive rollover or runtime deactivation.