WinCC Flexible 2008 Tag Licensing: Runtime Licenses and Limits

Overview

WinCC Flexible 2008 is Siemens' configuration suite for SIMATIC HMI panels and PC-based visualization. Engineers reading the CA01 catalog frequently assume the entry 6AV6613-0AA51-3CA5 ("WinCC Flexible 2008 Advanced") ships with a fixed number of production Runtime tags because the catalog column says "with Runtime." That assumption is wrong, and the confusion is the root cause of most licensing questions on this platform.

The Advanced engineering software provides the configuration environment plus a Simulation Runtime for offline test of the engineered project. To run the same project on a production PC as the operator interface, you must purchase a separate tag-counted Runtime license per target machine. There is no "tag count" in the engineering license itself; the engineering license allows unlimited project engineering for the lifetime of the license holder, on as many projects as the engineer chooses.

This reference covers the four Runtime tag tiers Siemens sold for WinCC Flexible 2008 PC Runtime, the rules for what counts as a tag, the steps to activate a 4,096-tag project, Automation License Manager (ALM) behavior, a troubleshooting matrix, and the field-proven migration path to TIA Portal WinCC.

Engineering Software vs. Runtime: Why the Catalog Is Misleading

The CA01 product description for 6AV6613-0AA51-3CA5 contains the phrase "with Runtime." It refers to two embedded runtimes inside the engineering package:

• Simulation Runtime – a non-counted runtime used to test the engineered project on the engineering PC without a license key. It launches when the user starts the project with "Start Runtime" from WinCC Flexible ES and is intended for development and debug only.
• RT (Real) Runtime – the licensed PC runtime that is bundled with the engineering media for the installer's convenience. This runtime will start and will display the project if the appropriate tag-counted Runtime license is present on the Automation License Manager (ALM). If the license is missing, the runtime starts in degraded mode, displays a license warning banner, and either blocks operation after a grace period or throttles the polled tag count to 128 PowerTags (the smallest license tier).

Catalog Numbers and Tag-Tier Matrix

The four Runtime licenses for WinCC Flexible 2008 PC Runtime, all sold as single-seat, single-PC licenses, are:

Each Runtime license is bound to one PC. To run the same engineered project on N PCs in parallel (for example, a primary and a backup operator station), buy N Runtime licenses of the required tier. License mobility between PCs is possible only by deactivating the license from PC A via Automation License Manager and re-activating it on PC B; physical Certificate of License (CoL) keys were supported on older systems but were phased out by the 2008 era.

What Counts as a Tag in WinCC Flexible 2008

Not every variable in an HMI tag database consumes a license slot. The license count is governed by the PowerTag declaration under Project > Runtime Settings > PowerTags (or, in older builds, the tag list filter). The rules are:

1. External tags – tags connected to a PLC via MPI / PROFIBUS / Industrial Ethernet (for example, a DB word, an input byte) are eligible PowerTags. Each declared external PowerTag counts as one tag against the license.
2. Internal tags – tags local to the HMI (recipe buffers, script counters, password variables) are not PowerTags and do not consume a license slot, regardless of how many are declared.
3. Array tags – an array tag of N elements declared as a PowerTag counts as N tags (each element is a separate PowerTag). This is the easiest way to over-run a license; check array element counts before committing to a tier.
4. Limit value monitoring and scaling – do not consume additional tags. They are properties of the base tag, not separate PowerTags.
5. Multiplexing tags – only the tags used in the current screen consume license slots at runtime. Pre-declared multiplex pool tags do not, as long as they are properly defined in the multiplex configuration.
6. Pointer / indirect addressing – a pointer or P#-style reference does not consume additional PowerTags; it just changes which underlying external tag is being read at runtime.
7. Tags with cycle triggers vs. change triggers – both count once. The trigger type does not multiply the count.

Practical sizing example: a project that polls 1,200 discrete bits, 200 words, and 50 floats from an S7-300 over Ethernet has roughly 1,450 external PowerTags (each bit is a PowerTag; each word is a PowerTag; each float is two words = two PowerTags). Add 5 array tags of 100 elements each, and the tag total grows to 1,950. The right Runtime tier in this example is the 2,048-tag license.

Practical sizing example 2: a tank-farm HMI with 12 tanks, each tank holding 20 tags (level, temperature, pressure, pump status, valve commands, alarms), produces 240 PowerTags per tank × 12 = 2,880 PowerTags. Add 800 PowerTags for the loading-arm subsystem and 200 for the fire-suppression system, and the project lands at 3,880. The 4,096-tag license is the only tier that covers this scope without restructuring.

Selecting the Correct Runtime Tier

Use the following decision matrix when engineering a new project:

Always size for the as-built project, not the as-quoted one. Common reasons projects grow past the planned tier:

• Engineering adds an array of alarms not accounted for at quotation time. A 256-element alarm array can single-handedly push a 512-tag project to 768.
• A second PLC is integrated late, doubling the tag count for the cross-PLC reference screen.
• Script variables are mistakenly declared as PowerTags. This is a frequent rookie error: every VBScript variable promoted to a tag should be re-checked before commissioning.
• OPC tunnel tags are aggregated per-element rather than as a single multiplexed group. OPC DA normally exposes 1,000+ tags per server, so a 4,096-tag Runtime can be exhausted by a single OPC bridge.
• Audit-log and operator-action logging add 30 to 60 PowerTags per major subsystem.

How to Engineer and Activate a 4,096-Tag Project

The 4,096-tag tier is the largest Runtime license Siemens sold for the WinCC Flexible 2008 PC Runtime. Use the following procedure to reach that count legally and to commission the license on the target machine.

1. Install the engineering software from the 6AV6613-0AA51-3CA5 media on the engineering PC. Activate the license with the supplied CoL or via ALM using the order-confirmation license file from the Siemens license web portal.
2. Configure all PowerTags in the tag editor. Mark every external tag that must be polled as a PowerTag; leave internal tags and unused array elements un-marked. Verify that no script-generated or temporary tag is in the PowerTag set.
3. Compile the project (Project > Compiler > Generate). Open the compiler log and record the reported PowerTag count. If it is below 4,096, the 4,096-tag license is the correct choice; if it is above 4,096, the project is outside the license ceiling and you must either reduce the PowerTag set or split the project across multiple HMI stations.
4. Test with Simulation Runtime on the engineering PC. The Simulation Runtime is license-agnostic; it will simulate any tag count, so it is not a useful gauge of license adequacy. It is, however, essential for confirming screen logic, scripts, and alarm handling before the target PC is touched.
5. Purchase the 4,096-tag Runtime license 6AV6 613-1GA51-3CA0 from Siemens (one per target PC). For a redundant PC pair, buy two.
6. Install WinCC Flexible 2008 Runtime on the target PC from the same engineering media (or from a standalone Runtime media, depending on what was ordered). The Runtime is the executable and supporting services; it is independent from the engineering environment.
7. Activate the Runtime license on the target PC using Automation License Manager. Transfer the license file from the CoL or from the Siemens license web portal to the local License directory. The ALM service detects the new file within 60 seconds.
8. Transfer the engineered project to the target PC. Launch the Runtime. The license banner should not appear, and the Runtime should enter normal operation.
9. Verify with the ALM Status tab that the license "WinCC Flexible 2008 Runtime 4096 PowerTags" is checked out to this PC and is not in the grace period. The Status tab also shows the time remaining on any trial license.
10. Perform a 24-hour burn-in with the project running, simulating operator actions and alarm acknowledgements. Verify in the Runtime log that no PowerTag has been dropped to the "unlicensed" placeholder.

Automation License Manager Behavior

The Automation License Manager (ALM) is the service that arbitrates licenses between the engineering PC, the Runtime PC, and a license server (when present). For WinCC Flexible 2008 the following behavior is relevant:

• Local license files (.lic) are placed in C:\Program Files\Siemens\Automation\SiemensALM\License by default. The path can be redirected in ALM's settings.
• ALM checks out a license only when the WinCC Flexible Runtime service starts. If the service is stopped, the license returns to the local pool within 60 seconds.
• If the ALM service itself is stopped, the WinCC Flexible Runtime starts in trial mode (1-hour grace), then refuses to start.
• When the license file is moved to a license server (redundant floating license), each Runtime PC must have a network path to that server. A network blip longer than 10 minutes puts the Runtime into a 1-hour offline grace, after which it stops.
• On a redundant license server pair, ALM performs license mirroring at 30-second intervals. A primary failure shifts all PCs to the secondary within 2 minutes; no PC intervention is required.
• The ALM log files in %LOCALAPPDATA%\Siemens\Automation\SiemensALM\logs record every checkout and check-in. The log is the first place to look when a Runtime reports a missing-license error.

Always confirm in the ALM log that the license is being checked out by the correct Runtime process (WinCC_RT.exe) and not by the Simulation Runtime or by an orphaned engineering process. A common field problem is that a developer closes the engineering software, but the project was last run from the engineering environment, leaving the simulation process holding a license slot for 60 seconds and starving the production Runtime.

Troubleshooting License Issues

Panel Runtime vs. PC Runtime

WinCC Flexible 2008 also targets SIMATIC panels (KTP, TP, MP, OP, Mobile Panel) — but the licensing model differs from PC Runtime. Panel runtimes are licensed per panel, not per tag count, and the license is loaded onto the panel by the engineering software at the time of project transfer. Common panel families and their relevant licensing context:

• KTP400 / KTP600 / KTP1000 / KTP1200 – license is "WinCC Flexible 2008 Compact" or higher, transferred to the panel by ES at first transfer. No Runtime tag license is required for the panel itself.
• TP1500 / TP1900 / TP2200 – same Compact / Standard / Advanced licensing, panel-licensed.
• MP 277 / MP 377 – WinCC Flexible 2008 Standard or higher; panel-licensed.
• PC Runtime – the tag-counted model described in this article.

Migration to TIA Portal WinCC

WinCC Flexible 2008 is in the Siemens product lifecycle "Discontinued" phase. Spare-part support is time-limited. New projects should be engineered in TIA Portal WinCC (TIA V17 / V18 / V19), which uses a different licensing model:

• Engineering: SIMATIC WinCC Comfort / Advanced / Professional (TIA Portal) – annual subscription or perpetual CoL.
• Runtime for PC: WinCC Runtime Advanced tag-counted licenses (128 / 512 / 2,048 / 4,096 / 8,192 / 65,536) or WinCC Runtime Professional (PO-tag counted, 100 / 256 / 1,024 / 2,048 / 4,096 / 8,192 / 16,384 / 32,768 / 65,536 / 131,072 / 262,144).
• Panel-based Runtime: WinCC Runtime Comfort / Advanced, with panel-specific MLFBs (for example, KTP1200, TP1500).

Migrating a 4,096-tag WinCC Flexible project to TIA Portal preserves the project structure (TIA Portal's WinCC Advanced can read .hmi files via the migration tool) but requires a re-license. The old 6AV6 613-1GA51-3CA0 license does not carry over. In some regions, Siemens runs a trade-in program for WinCC Flexible licenses; consult the Siemens sales channel for the latest terms.

Specifications and Field-Proven Caveats

Ordering Checklist for a New Project

Before sending a purchase order, confirm the following with the engineering team and the customer:

1. The compiled PowerTag count from the Generate step, not the estimated count.
2. The number of Runtime PCs (primary, backup, training, simulation bench).
3. Whether the project will migrate to TIA Portal in the next 18 months (which may justify skipping the 4,096-tag license and buying TIA Portal Runtime Advanced instead).
4. Whether the customer has a Siemens license portal account; if not, set it up before delivery so the .lic files can be re-downloaded in case of PC replacement.
5. Whether the target PC has a stable network path to a license server, or whether the license will be local-only.
6. Operating system version on the target PC and whether Microsoft VC++ redistributables are present.

Frequently Asked Questions