Renaming Control Module Types (CMT) in Master Data Library - Synchronizing Renamed CMTs with Instances in SIMATIC PCS 7

When renaming an existing and deployed Control Module Type (CMT) in the Master Data Library (e.g., renaming MS01 to SBE_MS01 in SIMATIC PCS 7 V9.0) and finding that the Synchronization dialog indicates differences ('Assigned name of CMs is different - Source A: empty, Source B: SBE_MS01'), the behavior occurs because renaming the chart folder only updates the file container, leaving the internal Technological I/O type attribute desynchronized. To resolve this, open the renamed CMT in the library, open 'View > Technological I/Os', click the root technological node, and update the 'Name' attribute to match SBE_MS01. Then re-run the Synchronization dialog from the Plant Hierarchy, select the discrepancy row, and click 'Synchronize'; PCS 7 will seamlessly update all instantiated Control Modules (CMs) across the plant.

Control Module Type (CMT) Naming Architecture: Container Name vs Technological Type Name

In SIMATIC PCS 7 (V8.1, V8.2, V9.0), Control Module Technology represents an advanced engineering methodology that encapsulates continuous automation logic into standardized object classes. A Control Module Type (CMT) defined in the Master Data Library (MDL) has two distinct naming layers:

CFC Container Name: The physical filename and chart title displayed in SIMATIC Manager Component View (e.g., MS01).
Technological Type Name: The internal object-oriented class identifier defined inside the chart under View > Technological I/Os (the top-level root node in the technological tree).

When engineers rename an existing CMT directly in the SIMATIC Manager project tree from MS01 to SBE_MS01, they only rename the outer CFC container. The internal technological definition frequently retains the old name or becomes unassigned, creating a structural mismatch.

Why the Synchronization Dialog Shows 'Source A: Empty, Source B: SBE_MS01'

When an engineer right-clicks the Plant Hierarchy and runs Synchronize... to propagate the renamed CMT to all plant instances:

The synchronization engine compares Source B (the Master Library CMT) against Source A (the instantiated Control Modules in the AS).
In the comparison grid, the engineer observes:

'Difference: Assigned name of CMs is different (Source A: empty, Source B: SBE_MS01)'

This occurs because the instantiated CMs still carry pointers to the old type identifier (MS01), while the library template presents the newly renamed identifier (SBE_MS01).
The synchronization wizard highlights this row to warn the engineer that confirming synchronization will formally rebind all instantiated charts to the new technological class name.

Updating the Technological I/O Root Node in the Master Data Library

To ensure clean, deterministic synchronization without orphaned metadata:

Open the renamed CMT chart (SBE_MS01) in the Master Data Library.
Select menu View > Technological I/Os (or click the icon on the toolbar).
In the left pane of the Technological I/O window, click the very top root item (the Control Module Type node).
In the properties pane, locate the field Name or Assigned name of CMs.
Verify that it matches the new name: SBE_MS01.
If this field is empty or contains the old string MS01, update it manually and save the chart.

Executing Bidirectional CMT-to-CM Instance Synchronization

Once the library template is cleanly configured, synchronization must be executed across the plant hierarchy:

In SIMATIC Manager Plant View, right-click the root Plant Hierarchy folder or target AS station and select Plant Hierarchy > Synchronize....
In the synchronization comparison table, locate the row showing the name discrepancy.
Select the checkbox for that row and click the Synchronize button.
The PCS 7 engineering engine updates all instantiated Control Modules across all plant charts, rebinding their internal GUIDs and updating the assigned type attribute to SBE_MS01 while preserving all local parameterizations (I/O addresses, block comments, and tuned setpoints).

Comparative State Matrix: CMT Renaming Discrepancies and Resolution

The following table summarizes the behavior of CMT renaming across engineering phases:

Engineering ActionLibrary CMT StatusPlant Instance (CM) StatusSynchronization Dialog DisplayNext Required ActionRenamed in Tree OnlyContainer: SBE_MS01, Tech Node: MS01Bound to MS01Difference: Name mismatchUpdate Technological I/O root nodeTech Node UpdatedContainer: SBE_MS01, Tech Node: SBE_MS01Bound to MS01Difference: A: MS01, B: SBE_MS01Execute 'Synchronize' commandSynchronization ExecutedContainer: SBE_MS01, Tech Node: SBE_MS01Bound to SBE_MS01No differences found (Green)Compile CFC (Changes only)Instance DivergentLibrary template modifiedLocal manual edits made in CMWarning: Overwrite local edits?Decide whether to keep local variant

Step-by-Step Procedure to Rename a CMT and Synchronize All Plant Instances

Follow this exact sequence to rename a CMT and synchronize instances in PCS 7 V9.0:

Archive the Multiproject:
- Create a safety archive in SIMATIC Manager (File > Archive).
Rename CMT in Master Data Library:
- In the Master Data Library Plant Hierarchy, right-click the CMT (e.g., MS01) and select Rename.
- Enter the new name: SBE_MS01.
Update Technological I/O Root Node:
- Double-click SBE_MS01 to open the CFC editor.
- Select View > Technological I/Os.
- Click the top root node in the tree. Ensure the property Name reflects SBE_MS01.
- Save and close the chart.
Run Synchronization Wizard:
- In SIMATIC Manager, select the AS project or plant hierarchy folder.
- Select menu Plant Hierarchy > Synchronize....
- In the comparison window, locate the entry where Source B displays SBE_MS01.
- Select the row and click Synchronize.
- The progress bar completes; verify that all instances now report 'Identical'.
Compile and Verify:
- In SIMATIC Manager, execute CFC > Compile > Changes only.
- Perform an OS Compile (Changes only) to verify tag naming continuity.

Verification

Verify successful CMT renaming through these checks:

Open any instantiated motor chart in the Plant Hierarchy.
Double-click the chart header to open Object Properties: confirm that the Type field displays SBE_MS01.
Open the chart in CFC. Confirm that all technological blocks, wiring, and I/O connections remain intact.
Re-open Plant Hierarchy > Synchronize...: confirm that the dialog reports 'No differences detected between library and instances'.
Verify that in CFC Test Mode, online monitoring of the instantiated blocks functions without communication faults.

Limitations and Operational Precautions

WinCC Block Icon Tag Paths: Renaming the CMT template does not rename the individual instantiated chart instances in the plant hierarchy (e.g., Motor_101 remains Motor_101). Therefore, WinCC tag paths and faceplate links remain completely unbroken.
Avoid Renaming During Plant Production: While synchronization and changes downloads can be executed in RUN mode, performing mass type synchronizations across hundreds of active charts should be scheduled during maintenance intervals.
Plant Automation Accelerator (PAA) Alignment: If the project is linked to PAA, rename the type in PAA first to maintain bi-directional database synchronization.

Engineer FAQ

Will renaming a CMT rename all my motor charts in the plant?

No. Renaming the Control Module Type (CMT) changes the template class name (e.g., SBE_MS01). The individual instantiated charts retain their plant tag names (e.g., M_101, M_102).

Why did the synchronization window show 'Source A: empty'?

Because the instance in the plant did not yet have the new name SBE_MS01 registered in its internal technological attribute; it was still pointing to the old name or had an unlinked pointer.

Can I rename a CMT back to its original name if needed?

Yes. The renaming and synchronization process is fully reversible by following the same procedure in reverse.

Does CMT synchronization require stopping the CPU?

No. If only the CMT class name was renamed without altering block types or memory-intensive algorithms, changes can be downloaded via 'Changes Download in RUN'.

What is the difference between Synchronize CMT and Update Block Types?

Update Block Types updates compiled S7 Function Blocks (FB). Synchronize CMT updates the technological CFC chart layout, wire connections, and technological I/Os.