Resolving WinCC.LicenseLimit Display in TIA Portal V15

1. Problem Overview

The WinCC.LicenseLimit indicator is published through the SIMATIC Shell on every engineering station (ES) and runtime PC in a TIA Portal V15 WinCC Professional project. When an operator or commissioning engineer opens the SIMATIC Shell, the field is expected to enumerate the installed WinCC license and its associated power tag / external tag capacity. If the entry is missing, blank, or shows an unexpected value, the engineering station cannot reliably determine whether a target PC has sufficient licensed tags to host a compiled WinCC Runtime Professional project. Loading a project across the network may be blocked, the project may fail to compile, or the runtime may refuse to start because the licensing handshake cannot complete.

This article documents the diagnostic path for a missing or incorrect WinCC.LicenseLimit display in WinCC Professional V15 (part of the TIA Portal V15.0 / V15.1 engineering suite). Procedures are written for engineers performing on-site commissioning, factory acceptance tests (FAT), and remote diagnostics.

2. WinCC License Architecture in TIA Portal V15

WinCC Professional V15 licensing is based on three components that must be present and consistent across the ES and the target PC:

1. Software License (Base): The WinCC Professional base license authorizes the engineering or runtime installation.
2. Tag-count License (PowerPack): Scalable licenses in steps of 128, 512, 2048, 4096, 8192, 16384, 32768, 65536, and the unrestricted maximum.
3. Option Licenses: Add-ons such as WinCC Recipes, WinCC Logging, WinCC User-Admin, WinCC WebNavigator, and WinCC DataMonitor.

Each license is stored in the SLC (Siemens License Container) on the local hard disk. The Automation License Manager (ALM) reads the container and exposes the count to the WinCC runtime services. The WinCC License Service (service name WinCC-LicenseService on Windows, executable CCLicenseService.exe) publishes the LicenseLimit value over the network via SIMATIC Shell.

2.1 License Variants Available for WinCC Professional V15

Reference the official licensing documentation at docs.tia.siemens.cloud – Licensing STEP 7 and WinCC and the licensing FAQ PDF at support.industry.siemens.com – WinCC TIA Portal Licenses (PDF) for the full tag-count matrix including the V15 generation.

3. SIMATIC Shell and the LicenseLimit Indicator

SIMATIC Shell is a Windows Explorer namespace extension installed with TIA Portal. It appears under Network > SIMATIC Shell when you open Windows Explorer. The shell enumerates all WinCC-capable PCs reachable on the local network. For each remote PC, the ES reads three fields:

• ComputerName – NetBIOS name of the target PC.
• WinCC.Version – Installed WinCC Runtime Professional version (e.g., V15.0, V15.1, V16.0).
• WinCC.LicenseLimit – The maximum number of power tags the installed license allows.

The LicenseLimit value is the deciding factor when the ES compiles a project for distribution: if the destination PC reports a value below the project's required tag count, the ES raises an error and aborts the load operation. If the value is missing entirely, the load proceeds with a warning and falls back to optimistic assumptions, which can cause runtime activation to fail on the target.

3.1 Where to Find the LicenseLimit

1. Open Windows Explorer on the engineering station.
2. Navigate to Network > SIMATIC Shell.
3. Double-click the target PC entry.
4. Read the WinCC.LicenseLimit property pane on the right side.

If the property pane is empty, the WinCC License Service is not reachable on the target PC. Do not assume the absence means "unlimited" – it is a network or service fault.

4. Root Causes of a Missing or Incorrect LicenseLimit

5. Network Configuration Requirements

SIMATIC Shell uses a combination of SMB (Server Message Block) and a Siemens-proprietary UDP broadcast for PC discovery. The minimum required open ports and services are:

All participating PCs must be members of the same Windows workgroup or domain. Mixed workgroup/domain memberships where the ES is in a domain and the RT PC is in a workgroup require explicit credential mapping in the Windows Credential Manager. The complete network requirements are documented in Siemens FAQ entry "What are the requirements for operating SIMATIC WinCC in a Windows network?".

6. Step-by-Step Diagnostic Procedure

Follow this ordered procedure before contacting Siemens support. Each step isolates one of the root causes listed in section 4.

Step 1 – Verify the WinCC License Service is running on the target PC

1. Open services.msc on the target PC.
2. Locate "CCLicenseService" (display name: "WinCC License Service").
3. Confirm Status = Running and Startup Type = Automatic.
4. If the service is stopped, right-click → Start.
5. If it fails to start, check the Windows Event Viewer under Applications and Services Logs > Siemens > Automation > License.

Step 2 – Verify the ALM service and license

1. Launch Automation License Manager from the Start menu.
2. Confirm the local PC is selected in the left tree.
3. Check that the WinCC Professional license is listed with status Valid.
4. Note the License Limit value. This is the value the License Service should publish.

Step 3 – Verify the license count matches the project

1. Open the WinCC project in TIA Portal V15 on the ES.
2. Navigate to Project tree > Runtime settings > Licensing.
3. Compare the project's configured power tag count with the target PC's installed limit.
4. If the project exceeds the target license, either reduce the tag count, install a larger license, or split the project.

Step 4 – Test SIMATIC Shell enumeration

1. On the ES, open Windows Explorer → Network.
2. Click SIMATIC Shell.
3. Confirm the target PC appears in the list.
4. Double-click it. Confirm WinCC.Version and WinCC.LicenseLimit are populated.

Step 5 – If the target PC is not listed at all

1. Verify both PCs are in the same subnet and workgroup/domain.
2. Disable Windows Firewall temporarily as a test (netsh advfirewall set allprofiles state off). Re-enable after the test with a proper rule set.
3. Open a command prompt and execute net view \\<TargetPC>. If this fails, the issue is at the network/SMB level, not WinCC-specific.
4. Confirm Function Discovery Resource Publication and SSDP Discovery services are running on the target.

7. Resolving Common Errors

7.1 Error: LicenseLimit = 0 despite valid ALM license

Cause: The ALM cache is out of sync with the License Service. This occurs after license transfer operations, virtual machine snapshots, or restoring an image with a different SLC hardware fingerprint.

Resolution:

1. Stop the CCLicenseService.
2. Delete the contents of %PROGRAMDATA%\Siemens\Automation\Licensing (do not delete the folder itself).
3. Restart CCLicenseService.
4. Re-launch ALM and confirm the license is detected.
5. Re-check SIMATIC Shell.

7.2 Error: "The license is missing or invalid" during project load

Cause: The project tag count exceeds the LicenseLimit on the target PC. TIA Portal blocks the load to prevent runtime activation failure.

Resolution:

• Reduce the number of power tags in the project to match the target license, OR
• Install a larger PowerPack license on the target PC, OR
• Switch to a WinCC max. license (article 6AV2105-0LA05-0AA0 for V15).

7.3 Error: Shell shows wrong WinCC.Version

Cause: Multiple WinCC versions are installed side-by-side (for example, V15 RT Professional and V16 RT Professional on the same PC). The shell returns the version of the most recently installed runtime.

Resolution: Uninstall the older runtime version, or explicitly set the default version in SIMATIC Shell > Settings if available in your service pack.

7.4 Error: LicenseLimit visible locally but not remotely

Cause: The remote ES cannot read the License Service over the network. The SMB session is established (PC visible) but the DCOM call to CCLicenseService is blocked.

Resolution: Add a Windows Firewall inbound rule for C:\Program Files\Siemens\Automation\WinCC\bin\CCLicenseService.exe on the target PC, allowing TCP traffic from the ES subnet on all ports (the service binds to a dynamic port).

8. Tag-Count License Scaling Reference

For engineers deciding which license to install on a new RT PC, the following table maps common project sizes to the recommended V15 license. Power tags are the most restrictive count; ensure the project stays within budget even after commissioning additions.

Each power tag typically corresponds to one PLC address. Aggregate tags (indirect addressing) are not power tags but count against the external tag limit, which is 1k, 10k, or 100k depending on the installed license variant. See Licensing STEP 7 and WinCC for the full matrix.

9. Verification and Commissioning Checks

After applying the corrective steps, perform the following verification sequence before signing off the commissioning report:

1. Local license test: On the target PC, open ALM and confirm the WinCC license is Valid with the expected Power Tag limit.
2. Service test: In services.msc, confirm CCLicenseService is Running and Automatic.
3. Network test: From the ES, open SIMATIC Shell and confirm the target PC displays both WinCC.Version and WinCC.LicenseLimit correctly.
4. Project test: In TIA Portal, select Online > Load to target system > RT PC. The load should proceed without a licensing error.
5. Runtime test: On the target PC, launch WinCC Runtime Professional. Confirm the project starts and remains in Run mode for at least 10 minutes without falling back to a demo banner (which indicates an unlicensed runtime).
6. Failure-mode test: Temporarily disable CCLicenseService. Confirm WinCC Runtime transitions to a "License missing" state within 60 seconds (the service heartbeat interval), demonstrating the watchdog is functional.

10. Preventative Measures

• Image hardening: When deploying WinCC RT images with a cloning tool (e.g., Symantec Ghost, Acronis), re-arm the SLC after each deployment to avoid the hardware fingerprint mismatch that zeros out the LicenseLimit.
• Backup the ALM database: Export the ALM license keys via ALM > License Key > Export and store them in a secure vault. Re-import is the fastest recovery from a corrupted SLC.
• Firewall baseline: Document and apply the Siemens-recommended firewall rules from FAQ 868014. A baseline Windows Firewall with default rules breaks SIMATIC Shell discovery on Windows 10/11 / Server 2019+.
• Version matrix: Maintain a site-wide table of ES versions and target RT versions. Mismatches cause subtle LicenseLimit display errors that are easy to misdiagnose as licensing issues.
• Periodic audit: Run the verification sequence from section 9 quarterly. LicenseLimit anomalies often appear weeks before they cause a runtime failure.

11. Quick Reference: Service and File Locations

FAQ