Synchronizing Control Module Commands Embedded in Equipment Module Types (EMT) in PCS 7

When a new command is added to a Control Module Type (CMT) in the Master Data Library (MDL), it does not automatically appear under the Basic Requirements of an Equipment Module Type (EMT) where that CMT role was previously assigned. In SIMATIC PCS 7, the EMT stores a static technological interface snapshot of assigned CMT basic requirements. To propagate the newly added CMT command to the EMT, open the EMT in the Master Data Library, re-assign or refresh the Control Module Assignment role, and execute 'Options -> Synchronize Technological Types' across the Plant Hierarchy to update all instantiated EMT and SFC Type instances across the multiproject.

CMT and EMT Technological Hierarchy Architecture

SIMATIC PCS 7 introduced the Technological Engineering workflow (starting in V8.1 and expanded in V8.2 and V9.0) using Control Module Types (CMT) and Equipment Module Types (EMT). This object-oriented architecture follows ISA-88 modular standards:

Control Module Type (CMT): Encapsulates lower-level process actuators and sensors (motors, valves, analog transmitters) along with their I/O signals, parameters, messages, and technological commands (e.g., Start, Stop, Open, Close).
Equipment Module Type (EMT): Encapsulates unit operations and coordination logic (e.g., a dosing station or mixer reactor) using an integrated SFC Type. The EMT defines Basic Requirements that specify the roles of required CMTs.
Technological Actions: Inside the EMT's SFC Type, step actions command the lower-level CMTs using the technological commands exposed by the Basic Requirements.

Root Causes of Command Propagation Latency in Master Data Libraries

When an automation engineer adds a new technological command to an existing CMT in the Master Data Library, the command is immediately visible in the CMT editor. However, expanding the corresponding CMT role under the EMT's Basic Requirements fails to display the new command because:

Static Role Definition: In the EMT editor, an assigned Basic Requirement captures the technological signature of the CMT at the moment the assignment is created. It does not automatically poll the CMT for subsequent interface expansions.
Decoupled SFC Action Binding: SFC technological actions can reference commands directly if manually entered, but the graphical browser in the SFC editor relies on the EMT's internal interface cache.
Missing Master Data Synchronization: Changes made in the Master Data Library must be formally compiled and synchronized using the PCS 7 Technological Synchronizer before child EMTs and instantiated project charts inherit the modified command definitions.

Technological Object Synchronization and Interface Matrix

The following table compares the technological engineering components and their synchronization mechanisms:

Technological ObjectDefinition LocationContained ElementsSynchronization TriggerImpact on Project InstancesControl Module Type (CMT)Master Data Library -> TemplatesBlocks, Signals, Parameters, CommandsUpdate Block Types / SynchronizeUpdates chart instances and signal linksBasic RequirementEMT Technological EditorRequired CMT role and supported commandsRe-assignment or Type RefreshUpdates EMT interface signatureEquipment Module Type (EMT)Master Data Library -> TemplatesSFC Type, Basic Requirements, LogicSynchronize Technological TypesUpdates project EMT charts and SFC instancesSFC Type Step ActionEmbedded inside EMTTechnological commands executing on CMTsSFC Type Compilation & DownloadControls runtime step execution on controller

Step-by-Step Procedure to Synchronize CMT Commands into EMT SFC Instances

To push a new CMT command into the EMT and project instances according to PCS 7 Compendium Part C guidelines:

Update and Save CMT in Master Data Library:
- In the Master Data Library, open the CMT under the Control Module Types folder.
- Add the new Command (e.g., JogForward) under the Commands folder.
- Configure the internal command logic and parameters. Save and close the CMT.
Refresh Basic Requirement in EMT:
- Open the EMT in the Master Data Library.
- In the Technological Editor pane, locate the Basic Requirements folder.
- Right-click the assigned CMT role and select Update / Re-assign (or delete and re-drag the updated CMT from the library into the Control Module Assignment).
- Expand the [+] icon under the Basic Requirement to verify that the new command now appears in the list.
Synchronize Technological Types Across Multiproject:
- In SIMATIC Manager Plant View, select the Multiproject or target project.
- From the menu bar, select Options -> Synchronize Technological Types.
- The Technological Synchronizer dialog compares the Master Data Library with all project instances.
- Click Synchronize to propagate the new commands and block modifications to all instantiated CMTs and EMTs.
Update SFC Technological Actions and Compile:
- In the EMT's SFC Type, assign the new command to the desired step actions.
- Perform a CFC/SFC Compilation with scope Changes Only and download changes to the CPU in RUN.

Verification

Verify command synchronization:
1. Open the project EMT instance in CFC.
2. Open the embedded SFC instance and inspect the target step properties.
3. Under the Object tab, verify that the newly added command appears in the drop-down list of available technological commands.
4. Test the SFC step execution online to confirm that activating the step triggers the corresponding command bit on the instantiated CMT block.

Limitations and Operational Precautions

Compendium C Synchronization Rules: Never modify technological commands directly inside instantiated project charts; all modifications must originate in the Master Data Library to preserve template synchronization.
SFC Step Re-Verification: Adding commands to an EMT does not automatically modify existing SFC step actions. Engineers must manually wire the new command into the appropriate sequencer steps.
CPU Memory Footprint: Synchronizing multiple EMTs and CMTs generates new data block interfaces and internal interconnections, consuming AS work memory.

Engineer FAQ

Can I use a new CMT command in an SFC action even if it doesn't show under Basic Requirements?

Technically yes, if typed manually or mapped via underlying block pins, but this bypasses technological consistency checks and risks broken links during future synchronizations.

What document outlines the official Siemens synchronization rules for CMT and EMT?

SIMATIC PCS 7 Compendium Part C - Equipment Modules and Control Modules (Technical Functions with CMT and EMT) details all synchronization procedures.

Does synchronizing technological types require a CPU STOP?

No. In PCS 7 V8.2 and V9.0, synchronizing technological types generates standard CFC chart changes that can be downloaded to the CPU in RUN.

Why does deleting and re-adding the Basic Requirement solve the issue?

Re-assigning the Basic Requirement forces the EMT editor to recreate its internal COM interface schema, pulling the latest XML definition from the Master Data Library.