Continuous Function Chart (CFC) Support for SIMATIC S7-1200 and S7-1500 Controllers

Continuous Function Chart (CFC) is natively supported on SIMATIC S7-1500 controllers starting in TIA Portal V17 using the dedicated TIA Portal CFC option package, but remains completely unsupported on SIMATIC S7-1200 controllers. In classic STEP 7 V5.x and SIMATIC PCS 7, CFC (such as 6ES7658-1EX58-0YA5) is strictly reserved for S7-400 and S7-300 automation systems and cannot be installed into TIA Portal. For S7-1200 applications requiring interconnected block logic, engineers must utilize Function Block Diagram (FBD) or Structured Control Language (SCL) within standard STEP 7 Basic or Professional.

Architectural Evolution of Continuous Function Chart (CFC)

Continuous Function Chart (CFC) is a graphical programming language compliant with IEC 61131-3 that enables engineers to instantiate, configure, and interconnect pre-tested function blocks within visual sheets. For over two decades, CFC served as the core technological programming backbone of SIMATIC PCS 7 and STEP 7 V5.x systems running on S7-400 and S7-300 controllers.

With the introduction of the Totally Integrated Automation (TIA) Portal framework, graphical block interconnection was initially omitted in favor of standard LAD/FBD networks. However, with the release of TIA Portal V17 (Entry ID 109797803), Siemens reintroduced CFC as an optional engineering tool designed specifically for complex continuous processes running on advanced SIMATIC S7-1500 controllers.

CFC Compatibility Constraints: S7-1200 vs S7-1500

Siemens enforces strict hardware tier boundaries regarding CFC compiler support:

SIMATIC S7-1500 Controllers: Fully supported in TIA Portal V17, V18, and newer versions when using S7-1500 CPUs (firmware V2.8 or higher), S7-1500 Software Controllers (CPU 1507S / CPU 1508S), and Open Controllers. The TIA Portal CFC editor allows graphical chart organization, chart partitioning, and cyclic task assignment.
SIMATIC S7-1200 Controllers: Completely unsupported. S7-1200 CPUs possess hardware execution microkernels and memory architectures that do not support the automated DB generation, runtime group management, and dynamic pointer structures generated by the CFC compiler.

Differences Between Classic PCS 7 CFC and TIA Portal CFC

Engineers must distinguish the classic engineering license from the modern TIA package:

Licensing Separation: The classic engineering license SIMATIC S7, CFC V9.0 (order number 6ES7658-1EX58-0YA5) applies exclusively to STEP 7 V5.x and PCS 7. It cannot license or activate TIA Portal CFC.
TIA Portal CFC Package: TIA Portal requires its own distinct software package and license key (CFC for TIA Portal, order number 6ES7823-0BA00-0YA5).
Process Automation Libraries: Classic PCS 7 CFC is deeply integrated with the PCS 7 Advanced Process Library (APL) and automated driver wizards. TIA Portal CFC is designed for general machine automation or integration with the TIA Portal Process Automation Library (PA Library).

Alternative Graphic Engineering Approaches for S7-1200

Because S7-1200 controllers cannot host CFC, modular plant architectures requiring clear block interfaces should employ the following alternatives in STEP 7 Basic / Professional:

Function Block Diagram (FBD): Construct function blocks with parameter inputs and outputs connected visually across networks.
Structured Control Language (SCL): Encapsulate complex logic, analog scaling, and mathematical algorithms inside SCL blocks.
TIA Portal Cause & Effect (Safety Matrix): For safety logic, S7-1200F supports the Safety Matrix viewer for interlocking matrices.

Comparison Matrix of CFC Support Across Siemens Controllers

The table below contrasts CFC language support and licensing across Siemens controller families:

Controller PlatformClassic CFC (STEP 7 V5.x)TIA Portal CFC (V17+)Engineering SoftwareLicense Order Number (MLFB)SIMATIC S7-400 / AS 410Supported (Standard)Not ApplicableSIMATIC PCS 7 / STEP 7 V5.x6ES7658-1EX58-0YA5SIMATIC S7-300Supported (Optional)Not ApplicableSTEP 7 V5.x Professional6ES7658-1EX58-0YA5SIMATIC S7-1500 (FW >= V2.8)Not SupportedSupported (Optional)TIA Portal V17 / V18 Pro6ES7823-0BA00-0YA5SIMATIC S7-1500 Software ControllerNot SupportedSupported (Optional)TIA Portal V17 / V18 Pro6ES7823-0BA00-0YA5SIMATIC S7-1200Not SupportedNot SupportedSTEP 7 Basic / ProfessionalNot Available

Verification

Verify CFC engineering capability on the engineering station:

Open Automation License Manager (ALM). Verify whether CFC for TIA Portal or classic SIMATIC S7, CFC license is present.
In TIA Portal V17+, open a project with an S7-1500 CPU. In the project tree under the CPU, confirm the folder Charts is visible.
Double-click Add new chart; verify the CFC graphical editor opens and allows placing library blocks.
In an S7-1200 CPU project, observe that no Charts folder exists and the project tree restricts additions to Program blocks (OB, FB, FC, DB).

Limitations and Operational Precautions

Review the following technical precautions regarding CFC usage:

No S7-1200 Compatibility: Never attempt to install third-party translation tools or force CFC chart compilation onto S7-1200 CPUs, as the firmware reject the generated system function calls.
License Incompatibility: Do not purchase classic PCS 7 CFC licenses (6ES7658-1EXxx-0YA5) expecting them to activate CFC within TIA Portal. Always specify the TIA-specific MLFB.
Commercial Procurement Guardrail: Verify exact software license descriptions with your Siemens representative prior to purchasing options for TIA Portal.

Engineer FAQ

Can an existing PCS 7 CFC chart be migrated directly into TIA Portal CFC?

While TIA Portal V17+ introduces CFC for S7-1500, direct copy-paste migration of classic PCS 7 charts is not supported because the underlying block libraries (PCS 7 APL vs TIA libraries) and system calls differ fundamentally.

Does S7-1200 support any visual programming for process automation?

S7-1200 supports standard Function Block Diagram (FBD) and Ladder (LAD). For complex sequences, SCL scripts and standard state machines can be implemented within modular function blocks.