Feature request: Add license-key fallback and offline logging for WinCC Runtime Advanced

Summary: Add a runtime feature that allows WinCC Runtime Advanced to continue logging and operating when the license key is temporarily unavailable (networked license server unreachable or dongle disconnected), while ensuring licensing compliance.

Proposed behavior (defaults — adjustable in UI):

1. Grace period mode
   • If license check fails, enter a configurable grace period (default 72 hours) during which runtime continues full logging and HMI operation.
2. Local cached license
   • Securely cache a validated license token on the local machine for offline use; token expires after configurable interval (default 30 days).
3. Logging continuity
   • Continue writing logs locally to the configured archive path and to circular buffers; mark each log entry with a local offline flag and timestamp.
4. Deferred license check & sync
   • Periodically attempt to revalidate the license (configurable interval). On successful revalidation, automatically sync and sign previously flagged log entries with server-verified license metadata.
5. Tamper protection & audit trail
   • Sign local logs with a machine-bound key and include a tamper-evident checksum. Keep an append-only audit file recording offline periods, revalidation attempts, and user/admin overrides.
6. Admin warnings & alerts
   • Provide clear runtime UI notifications and optional SMTP/SNMP alerts when offline mode begins, at configurable intervals, and when grace period is about to expire.
7. Policy controls
   • Allow administrators to set policies per project: grace-period length, whether caching is permitted, whether logging continues in offline, and permitted features during offline.
8. Fail-safe modes
   • Option to restrict certain features (e.g., write access to critical controls) when license unavailable, per admin policy.
9. Reporting & compliance export
   • On reconnection, export a signed compliance report (offline durations, logs generated, revalidation status) for license audits.
10. Secure UI for overrides

• Allow authorized users to extend grace period manually with multi-factor confirmation; record all overrides in the audit trail.

Implementation notes (high level):

• Use strong cryptographic signing for cached tokens and local log checksums; bind tokens to machine identifiers.
• Provide settings in the Runtime Advanced Configuration editor and centralized management via TIA Portal/SMC.
• Ensure minimal performance impact by using streaming writes and background revalidation threads.
• Keep logs and audit data in a standardized format (e.g., JSONL) to ease ingestion into higher-level SCADA historian systems.

Default recommended settings:

• Grace period: 72 hours
• Cached license validity: 30 days
• Revalidation attempt interval: 15 minutes
• Admin warning at: start, 24h remaining, 4h remaining, 1h remaining

If you want, I can convert this into:

• A ticket template for your IT/license team, or
• A formal feature spec (with UI mockups and API details). Which would you prefer?

5. Additional Considerations

• Software Version: Ensure you're running a compatible version of WinCC that supports the features you're trying to use. Compatibility issues might arise with older or newer versions.
• Documentation: Consult the official Siemens WinCC documentation and knowledge base. Siemens provides extensive resources that can help with configuration, troubleshooting, and licensing.

1. Missing "Power Tag" License

In WinCC Runtime Advanced, logging is not a standalone feature. It is tied to Power Tags. Each tag you archive consumes a "Power Tag" license. If you have 50 process tags but only a 32-tag license, logging for 18 tags will fail, triggering this error.

2. Root Cause Categories

| Category | Possible Reason | |----------|----------------| | Missing License | License for "WinCC Logging for Runtime Advanced" not installed or not activated. | | Wrong License Type | Installed license (e.g., WinCC Comfort/Advanced) does not include logging runtime. | | License Not Loaded | License exists but Automation License Manager (ALM) failed to transfer it. | | Version Mismatch | License is for older version (e.g., v15) but used with newer runtime (v17+). | | Hardware Binding | License bound to different dongle/computer (e.g., after hardware change). | | Corrupted License File | License file damaged or incomplete. | | User Rights | Windows user lacks permission to access license storage or ALM. |