Best Practices for Duplicating CFC Logic in SIMATIC PCS 7 - Reusable Typical Charts, Master Data Library, and CMTs

When duplicating identical control logic across dozens or hundreds of technological units (e.g., 100+ motors) in SIMATIC PCS 7, the approved modern best practice is to deploy Control Module Types (CMT) in the Master Data Library (MDL). Creating a master CMT allows engineers to define function blocks, signal structures, optional variants, and Technological I/Os in a single template. Instances (Control Modules / CM) are instantiated across the Plant Hierarchy and bulk-parameterized via the Process Object View (POV) or mass-imported via CSV. If logic changes are required later, updating the master CMT in the library synchronizes all 100+ motor charts with a single click. For legacy PCS 7 systems prior to V8.0, the equivalent standard workflow is using Process Tag Types (PTT) with the Import/Export Assistant (IEA).

The Mass Engineering Challenge: Avoiding Repetitive Manual CFC Authoring

In medium-to-large process automation facilities (e.g., chemical plants, refineries, cement lines), engineers frequently encounter hundreds of identical or near-identical mechanical units: unidirectional motors, reversing drives, variable frequency drives, solenoid valves, and analog transmitters.

Manually drawing each CFC chart, placing blocks, wiring interconnections between channel drivers and technological blocks, configuring alarm limits, and testing faceplates for 100+ motors is prohibitively slow, expensive, and error-prone.

SIMATIC PCS 7 provides powerful mass-engineering tools to define standardized, reusable logic templates in a centralized library and instantiate them deterministically across the plant.

Legacy Duplication Methods: Chart-in-Chart and the Import/Export Assistant (IEA)

Historically in PCS 7 V6.x and V7.x, engineers relied on two duplication techniques:

Copy-Pasting Master Charts with Chart I/Os: A template chart was created with external Chart I/O pins, saved in the Master Data Library, and copied into Plant Hierarchy folders. However, once copied, the instances were completely severed from the master. If an interlock had to be modified later, an engineer had to manually update all 100 charts!
Import/Export Assistant (IEA): Charts were defined as Process Tag Types (PTT). An Import/Export file (CSV) was generated, allowing parameters, I/O addresses, and tag names to be populated in Microsoft Excel. While powerful, PTTs lacked flexibility for optional equipment variants (e.g., motors with vs without ammeters).

Modern Paradigm: Control Module Types (CMT) and Equipment Module Types (EMT)

Introduced in PCS 7 V8.0 and matured in V8.1, V8.2, and V9.0, Control Module Types (CMT) represent the state-of-the-art in PCS 7 mass engineering:

Technological Abstraction: Logic is modeled not merely as CFC blocks, but as technological entities possessing Technological I/Os (Signals, Parameters, and Messages).
Optional Blocks and Variants: A single CMT can encompass optional components (e.g., thermal overload monitoring, local control switch, vibration monitor). When instantiating, the engineer simply toggles checkboxes for which optional variants are active for that specific motor.
Centralized Lifecycle Synchronization: If a block parameter or wiring connection changes in the template, running 'Synchronize CMT' propagates the changes to all 100+ instances without overwriting instance-specific parameter tuning!

Managing and Sharing the Master Data Library (MDL) Across Projects

Reusable templates should never reside in a temporary project folder; they must be stored in the Master Data Library (MDL):

In SIMATIC Manager Multiproject view, every project is paired with a Master Data Library.
The library contains the approved block versions, SFC types, and Control Module Types.
Sharing Across Projects: The Master Data Library can be archived (File > Archive) as a standalone ZIP package and retrieved into other multiprojects. Corporate standards teams distribute standard MDL archives to ensure identical engineering typicals across worldwide corporate plants.

Comparative Workflow Matrix: Manual Copy vs IEA vs Control Module Types

The following table compares duplication strategies in SIMATIC PCS 7:

Criteria / CapabilityManual CFC Copy-PasteImport/Export Assistant (IEA)Control Module Types (CMT)PCS 7 Version SupportAll VersionsV6.0 to V8.2 (Legacy)V8.0, V8.1, V8.2, V9.0+ (Standard)Initial Template CreationDraw chart in libraryDefine Process Tag Type (PTT)Define CMT with Technological I/OsMass ParameterizationManual clicking per chartExcel CSV Import/Export FileProcess Object View (POV) / Excel CSVOptional Component VariantsRequires separate chartsRigid (Separate PTT per variant)Flexible (Checkboxes for optional blocks)Post-Commissioning Template UpdateManual edit on every chartRe-import CSV (Overwrites changes)One-Click Bidirectional SynchronizationIndustry 4.0 / PAA IntegrationIncompatibleIncompatibleFully integrated with Plant Automation Accelerator

Step-by-Step Procedure to Create, Instantiate, and Synchronize a CMT

Follow this procedure to deploy 100+ motors using Control Module Types:

Create Master CMT in Master Data Library:
- In SIMATIC Manager, open the Master Data Library's Plant Hierarchy.
- Right-click the folder -> Insert New Object > Control Module Type (name it CMT_Motor_1D).
- Open the chart. Insert MotL, Pcs7DiIn (run feedback), Pcs7DiOu (start command), and interlocks (Intlk02).
- Open View > Technological I/Os. Drag signals (FbkRun, StartCmd) and parameters (SetTime) into the Technological I/O tree.
Instantiate Control Modules in Plant Hierarchy:
- In the AS project Plant View, navigate to the target hierarchy folder (e.g., Area1\Unit01).
- Right-click -> Insert New Object > Control Module.
- Assign the master type: CMT_Motor_1D. Enter instance name (e.g., M_101).
Bulk Parameterize via Process Object View (POV):
- Select the plant hierarchy folder and switch to Process Object View.
- Under the Signals and Parameters tabs, assign I/O addresses (IW 512, Q 4.0) and setpoints in bulk (or copy-paste from Excel).
Synchronize Logic Updates:
- If logic in CMT_Motor_1D is modified later in the library, right-click the library -> Plant Hierarchy > Synchronize....
- Select all instances and confirm synchronization.

Verification

Verify correct logic duplication through these checks:

In SIMATIC Manager Plant View, verify that all instantiated motor charts display the Control Module symbol badge.
Open several instantiated charts (e.g., M_101, M_102) in CFC: confirm that internal wire connections match the master template.
Verify that physical I/O addresses and block comments match the engineering schedule.
Perform an AS-OS Compile. Verify that WinCC block icons generate cleanly with individual tag bindings for every instantiated motor.

Limitations and Operational Precautions

Un-synchronized Instances: If an engineer manually alters connections inside an instantiated CM chart without updating the master CMT, the instance becomes flagged as divergent. Future synchronizations will prompt to overwrite or preserve local edits.
Library Archive Discipline: Always maintain version numbers on Master Data Libraries (e.g., MasterLib_V1_2.zip). Never modify library templates during active plant operations without formal change control.
Chart Folder Compiles: After mass instantiating 100+ charts, perform an Entire CFC Compile to ensure proper runtime group sequencing.

Engineer FAQ

Can I convert an existing CFC chart into a Control Module Type (CMT)?

Yes. In SIMATIC Manager, right-click an existing CFC chart and select Plant Hierarchy > Create Control Module Type. The system converts the chart into a CMT template.

What is the difference between CMT and EMT?

A CMT (Control Module Type) represents a single control element (e.g., motor, valve, transmitter). An EMT (Equipment Module Type) represents a functional grouping of multiple CMs executing a coordinated task (e.g., dosing system, conveyor line, CIP circuit).