SIMATIC PCS 7 Licensing: AS/OS Engineering and OS Runtime Setup

Overview

SIMATIC PCS 7 is Siemens' distributed control system (DCS) used for continuous and batch process automation in industries such as chemicals, pharmaceuticals, power generation, water/wastewater, oil & gas, and pulp & paper. Unlike classic SIMATIC S7 PLCs paired with separate WinCC SCADA, PCS 7 is delivered as an integrated engineering and runtime suite that combines the SIMATIC Manager / TIA Portal engineering environment with the PCS 7 OS (Operator System) runtime based on WinCC. This integration is the source of recurring licensing questions because PCS 7 ships with two distinct license families that can be combined in several ways on a single engineering station, single OS station, or distributed multi-station architecture.

For a new user migrating from a classic SIMATIC Manager + WinCC Flexible / WinCC project, the central licensing questions are:

• Which license is required to configure a PCS 7 project (AS engineering, OS engineering, CFC/SFC, SCL)?
• Which license is required to run an OS server, OS client, or single OS station at runtime?
• Can a single PC be used for both engineering and runtime, and if so, which license model applies?
• How do license counts scale when the project grows from a single station to a multi-station / redundant OS server architecture?

This reference answers those questions using the official Siemens licensing model, the SIMATIC PCS 7 product page, and the PCS 7 Getting Started manual (PCS 7 Getting Started, Edition 01/2008). The article documents the conceptual license framework, the most common configuration patterns, and a verification checklist that an automation engineer can apply during commissioning and audit.

PCS 7 Licensing Architecture

PCS 7 separates license rights into two fundamentally different categories:

1. Engineering licenses – authorise the use of the PCS 7 engineering tools (CFC, SFC, SCL, OS picture editor, OS report designer, bulk engineering, version control / multi-project). Engineering licenses are floating or named-user, depending on the type, and are consumed only during the configuration phase.
2. Runtime licenses – authorise the execution of the PCS 7 OS runtime (the WinCC-based HMI/SCADA layer that talks to the AS via the S7 protocol suite). Runtime licenses are tied to the OS server, OS single station, or OS client on which the runtime is loaded and are counted per OS instance, not per user.

The split mirrors the classic WinCC / WinCC Flexible model: the configuration software and the runtime software are technically the same binaries, but require separate license keys. In WinCC flexible the runtime licence could be added to the same configuration PC; in PCS 7 the same principle applies via the OS Single Station license model.

Table 1 summarises the canonical license categories shipped with PCS 7.

AS/OS Engineering License

The PCS 7 AS/OS Engineering license (also called PCS 7 Engineering in some catalogues) authorises the engineer to:

• Create or open PCS 7 master data library, project, and multi-project.
• Insert, configure, and compile AS programs (S7-400 / S7-410H / S7-1500H AS stations).
• Author CFC (Continuous Function Chart) and SFC (Sequential Function Chart) charts.
• Edit OS pictures in the WinCC PCS 7 OS picture editor, including the standard PCS 7 faceplates (motors, valves, PID controllers, dosing, etc.).
• Configure the OS server / OS client split, user administration, archiving, and reporting.
• Perform bulk engineering, version comparison, and download to AS and OS targets.

Historically the AS/OS Engineering license is a floating license checked out from a license server (CodeMeter / WIBU / SIEMENS automation license manager). One license is consumed per concurrent engineering session, not per installed PC. The original poster's question — "do I need a separate license to run the OS on the same machine where I do engineering?" — is answered by the OS Single Station license, not by another engineering license.

For migration from SIMATIC Manager, note that a classic Step 7 Professional + WinCC configuration is not a valid substitute for the PCS 7 AS/OS Engineering license. The PCS 7 engineering tools (CFC, SFC, the PCS 7 OS picture system, SIMATIC Manager integration) ship only with the PCS 7 setup and require the corresponding license.

OS Runtime License Families

The PCS 7 OS runtime is delivered as a single binary (WinCC) that can be operated in three runtime topologies. Each topology has its own license model.

OS Single Station

The OS Single Station license is the simplest deployment: one PC acts as both OS server and OS client. It is the recommended topology for small plants, test rigs, training systems, and the engineering station that must also run a small OS for FAT (Factory Acceptance Test) or SAT (Site Acceptance Test). The runtime license count is exactly one per PC, regardless of how many OS areas the picture tree contains.

OS Server + OS Clients

When the OS is split into a central OS Server (which holds the project, archives, alarms, and tag database) and one or more OS Clients (which only display the picture tree and connect to the server), the OS Server license is required on the server PC and an OS Client license is required on every client PC. Client licenses are typically "unlimited" in the sense that a single OS Server license permits an arbitrary number of clients — but each client must be licensed to run the OS client runtime.

OS Redundancy

Critical processes add a standby OS Server. PCS 7 supports redundant OS servers (Master / Standby) that replicate tag values, alarms, and archives. To enable redundancy, the OS Redundancy license is added to the pair: the standby server consumes the redundancy license; the master is covered by its base OS Server license. For quadruple-redundant or higher configurations, additional pairs each consume one redundancy license.

Single Station Configuration (Engineering + Runtime on One PC)

The configuration most relevant to a new PCS 7 user — and the one described in the original licensing question — is the Single Station model, in which the same PC is used to engineer and to run the OS. This is officially supported by Siemens and is documented in the PCS 7 licensing examples (entry ID 32201963 on the Siemens Industry Online Support portal).

The required license set is:

1. One AS/OS Engineering license (floating, assigned to this PC during engineering).
2. One OS Single Station license (assigned to the same PC for runtime).

The two licenses can coexist on the same hardware. The engineering license is checked out only when the PCS 7 engineering tools (CFC, SFC, OS picture editor) are running. The OS Single Station license is checked when the OS Runtime process group is started. Because the licenses are independent, the PC can perform a download to the AS, edit CFC charts, modify OS pictures, and at the same time run the OS — the license manager keeps them on separate counters.

Distributed / Multi-Station Configurations

As the plant grows, the OS is typically split:

• One or more OS Servers (rack-mounted industrial PCs, often SIMATIC IPC) host the runtime data, alarms, and long-term archives. Servers can be redundant (Master / Standby).
• Several OS Clients (operator consoles, supervisor consoles, engineering clients with read-only view) display the picture tree and forward user input to the server.
• One or more Engineering Stations (ES) (often BSI/OS engineering clients) host the PCS 7 engineering tools. The ES license is independent of the OS Client/Server licenses.

PCS 7 supports a single-user system (one PC, AS/OS Engineering + OS Single Station), a multi-user system (OS Server + OS Clients), and a multi-user system with redundant OS Server. The license portfolio scales linearly with the number of OS server pairs and client PCs.

License Counting Rules and Bundling

The following rules are observed when sizing a PCS 7 license order:

1. Engineering license count = number of concurrent engineering sessions. If two engineers edit the same multi-project simultaneously, two engineering licenses are consumed. A license server (Automation License Manager) arbitrates the checkout.
2. OS Single Station = one license per PC running the OS in single-station mode. The license is counted per physical or virtual machine, not per OS area, not per AS connection count.
3. OS Server = one license per server instance. A redundant pair therefore consumes one OS Server license (on the master) and one OS Redundancy license (on the standby). A second redundant pair (e.g. plant A / plant B) consumes another OS Server + OS Redundancy.
4. OS Client = one license per client PC. A client license is not transferable between PCs without a license transfer. A client license is required even for "viewer-only" configurations.
5. Optional add-ons such as SIMATIC BATCH, SIMATIC Route Control, the PCS 7 Industry Library, the Maintenance Station, the Asset Monitor, the Web Navigator, and the WebUX option each have their own license rules. Refer to the catalog or the relevant add-on manual for the exact counting logic.

Migration from SIMATIC Manager + WinCC

Engineers moving from a classic SIMATIC Manager (Step 7 V5.x) + WinCC V7.x project to PCS 7 face a conceptual shift: the engineering tools are the same (SIMATIC Manager) but the OS project is no longer a stand-alone WinCC project — it is generated from the PCS 7 master data library and managed inside the multi-project. The licensing consequence is that you cannot purchase a WinCC V7 runtime license as a substitute for a PCS 7 OS license: the OS pictures, archives, and tag database in a PCS 7 project depend on PCS 7-specific DLLs (e.g. the PCS 7 faceplate framework) that are licensed only through the PCS 7 license family.

Migration path summary:

1. Inventory the existing Step 7 + WinCC project: AS program size, OS picture count, number of archive tags, number of clients.
2. Map the inventory to PCS 7 license requirements (AS count, OS topology, optional add-ons).
3. Order PCS 7 AS/OS Engineering and the appropriate OS runtime license bundle.
4. Convert the project to a PCS 7 master data library / multi-project structure (or, for greenfield, start from a PCS 7 template project).
5. Verify license activation with the Automation License Manager (start → Siemens Automation → Automation License Manager → show active licenses on the local PC and the license server).

Engineering Workflow and License Lifecycle

The license lifecycle of a typical PCS 7 project follows the project lifecycle:

1. Procurement — Order the AS/OS Engineering license and the OS runtime license(s) that match the OS topology. License keys are delivered as physical USB dongles, as downloadable CoL (Certificate of License) files, or via the Web License Manager (WLM) portal.
2. Installation — Install PCS 7 from the DVD / download. The setup recognises the present licenses and unlocks the corresponding features. Missing licenses are reported by the Automation License Manager as "missing" or "expired".
3. Engineering — Engineers log in to the engineering PC, the license server checks out a floating AS/OS Engineering license, and the engineer authors the project. When the engineer closes the tools, the license is released.
4. Commissioning — The OS Single Station / OS Server / OS Client license is activated on the runtime PC. The OS is started; the license is locked to the PC.
5. Operation — The runtime license stays on the PC for the operational lifetime. License transfer to another PC requires a license migration via the Automation License Manager.
6. Decommissioning — Licenses can be returned to the license pool (for floating licenses) or transferred (for single licenses) when the plant is rebuilt.

License Management Tools

Siemens ships the following tools to manage PCS 7 licenses:

• Automation License Manager (ALM) — the central utility to view, borrow, transfer, and return licenses. Available on every PC that runs PCS 7 software. Supports both WIBU-Systems CodeMeter and the legacy SafeNet Sentinel keys.
• Web License Manager (WLM) — a web portal where license certificates (CoL files) are downloaded and assigned to PCs.
• License Server — a dedicated PC that holds the master copy of the floating licenses and serves checkouts to engineering PCs across the plant network.

During commissioning, validate every PC with the following ALM check:

1. Start → Siemens Automation → Automation License Manager.
2. Select the local PC in the left pane; verify that the expected licenses appear in the right pane with status "Valid".
3. For floating licenses, switch the view to the license server; verify that the local PC can check out and check in the license.
4. Open a CMD prompt and run axcknf /info to display the local license cache (this command is part of the CodeMeter runtime).

Configuration Examples and License Sizing

The following worked examples translate the license rules into concrete order lists.

Example A: Single Station (FAT / Training / Test Rig)

One engineering PC, one AS, no clients.

• 1 × AS/OS Engineering (floating or single)
• 1 × OS Single Station

Example B: Small Plant (OS Server + 2 OS Clients, no redundancy)

• 1 × AS/OS Engineering
• 1 × OS Server
• 2 × OS Client

Example C: Critical Plant (Redundant OS Server + 4 OS Clients)

• 1 × AS/OS Engineering
• 2 × OS Server (one per plant unit, or one per redundant pair — check with the project scope)
• 2 × OS Redundancy (one per standby server)
• 4 × OS Client

Example D: Multi-Plant (Plant A + Plant B, both redundant, shared clients)

• 2 × AS/OS Engineering (one per plant engineering team)
• 4 × OS Server (two per plant, master+standby pair each consumes one)
• 4 × OS Redundancy (one per standby server)
• 8 × OS Client (four per plant)

Troubleshooting Matrix

Verification Checklist

After installation, work through the following checklist before the OS is started in production:

1. Open the Automation License Manager on the engineering PC. Confirm the AS/OS Engineering license is present with status "Valid".
2. Open the Automation License Manager on the OS Single Station / OS Server / OS Client PC. Confirm the expected runtime license is present with status "Valid".
3. If the OS topology is redundant, confirm the OS Redundancy license is present on the standby server with status "Valid".
4. Start the PCS 7 OS on the runtime PC. The OS splash screen must not report a demo mode or license warning.
5. Open a process picture, click a faceplate, and verify the standard PCS 7 faceplate framework loads without a license error.
6. If the project uses SFC visualization, open an SFC picture and verify the step/transition state colours are rendered (the SFC Visualization license is separate from the OS runtime license).
7. From an OS client, connect to the OS server. Verify that the client picture tree loads and that no "server not licensed" banner appears.
8. For redundant topologies, force a server failover (e.g. stop the master OS Server service). Verify the standby takes over within the configured switchover time and that no client loses its connection longer than the configured timeout.
9. Document the license set (catalogue numbers, CoL IDs, target PC hostnames) in the plant's license register. Update the register whenever a license is transferred or added.

Engineering Best Practices

• Treat the license server as production infrastructure. Back up the license server's hard disk image and document the restore procedure.
• Reserve one floating AS/OS Engineering license as a "hot spare" for on-call engineers, so that an outage does not stall the engineering team.
• Avoid installing PCS 7 engineering tools on the OS Server. Co-location can cause runtime hitches and complicates the license audit. Use a dedicated ES PC for engineering and a dedicated OS Server PC for runtime.
• Document the license topology (which PC holds which license) in the project's "PCS7_Project_Info" or in a separate license register inside the multi-project.
• Plan the license migration path before each Windows / PCS 7 version upgrade. Major version jumps (e.g. PCS 7 V8.x → V9.x) sometimes require new license certificates and a re-activation via the WLM portal.
• For audit purposes, keep the CoL files and the ALM export of the active licenses for at least the duration of the plant's warranty / regulatory retention period.

Field-Proven Caveats

• OS Single Station and OS Server are not interchangeable. A Single Station license does not enable the PC to act as a server for remote OS clients, and an OS Server license does not by itself permit a single-station deployment (the OS must be configured in "server with integrated client" or "standalone" mode in the project).
• An expired or missing runtime license typically does not prevent the OS from booting; it causes a "License not OK" alarm in the OS alarm log and a watermark in pictures. Operators can still acknowledge alarms, but the system is not in a state acceptable for many regulated processes. Treat the license alarm as a process-critical alarm in the alarm philosophy.
• Virtualisation (VMware vSphere, Hyper-V, Hyper-V with VMLite) is supported for OS Single Station and OS Server in many PCS 7 versions, but the license is still bound to the virtual machine's hardware fingerprint. Cloning a VM clones the fingerprint, which can confuse the license manager. Plan the VM template with a per-instance SID and MAC address.
• Some PCS 7 add-ons (e.g. SIMATIC BATCH Flexible) have a separate license model based on the number of batch units or the number of batch instances, not on the number of PCs. The license manager reports these counts; size them based on the recipe library, not on the hardware count.

FAQ