Renaming Control Module Instances and Removing Technological Name Suffixes in PCS 7 CMT

In SIMATIC PCS 7 Control Module Type (CMT) architecture, renaming a CFC chart in Component View does not remove automatic instance suffixes like '(1)' from the Control Module itself. A Control Module instance possesses two distinct naming layers: the CFC Chart Object Name and the Technological Name. To remove the '(1)' suffix, open the CFC chart, display the 'Technological I/Os' view (or open Plant View), select the root Control Module node in the technological tree, and modify the 'Name' attribute under Properties to match your desired plant designation.

Executive Summary

Beginning with SIMATIC PCS 7 V8.0 and expanded heavily in V8.1, V9.0, and V9.1, Siemens introduced Control Module Type (CMT) and Equipment Module Type (EMT) architectures to streamline standardized software engineering. When an engineer instantiates a CMT into a plant hierarchy folder or copies an existing instance, PCS 7 automatically appends numerical suffixes such as (1) to ensure unique technological naming.

A frequent usability challenge occurs when an engineer renames the CFC chart container in SIMATIC Manager (e.g., from 1174MO241(1) to 1174MO241), yet upon opening the chart or compiling OS pictures, the block icon and faceplate headers continue to display (1). This occurs because the technological object model is decoupled from the underlying Step 7 chart container. This article explains the architectural duality between CFC chart names and Technological Names, detailing the exact procedures to modify technological attributes in the Technological I/O view, Plant View, and Process Object View.

Architecture and Fundamental Mechanics

The technological engineering model in PCS 7 operates across two synchronized layers:

Container Object Layer (Component View): In standard Step 7, a CFC chart is a container for function blocks, runtime groups, and chart I/Os. Its name (e.g., 1174MO241) is stored in the project's S7 database and dictates the chart file identity on disk.
Technological Object Layer (Plant View / CMT Model): Inside a CMT-based chart, a top-level technological object named 'Control Module' (or 'Equipment Module') encapsulates the control strategy. This technological object owns attributes including:
- Technological Name: The functional plant identifier (e.g., 1174MO241).
- Author, Version, Description, and Comment.
- Technological I/Os: Parameters, signals, and messages bound to underlying block pins (e.g., StartAut, FbkRun, V).

When a CMT is instantiated or copied, the engineering system enforces unique naming across the plant hierarchy. If an instance already exists, PCS 7 appends (1) to both the chart container name and the internal Technological Name. Renaming the CFC chart in Component View changes ONLY the container name. Because WinCC compilation and APL faceplates extract the Plant Designation and Block Icon headers from the Technological Name (or hierarchy path), the lingering (1) inside the technological object remains active until explicitly updated in the technological attribute editor.

Step-by-Step Implementation Procedure

Follow these steps to rename the Control Module instance and eliminate the '(1)' technological suffix:

Method 1: Direct Modification via CFC Technological I/Os Pane
1. Open the CFC Chart:
- In SIMATIC Manager (Plant View or Component View), double-click the target CFC chart (e.g., 1174MO241) to open it in the CFC Editor.

Open the Technological I/O View:
- In the CFC main menu, select 'View > Technological I/Os' (or click the 'Technological I/Os' icon on the toolbar).
- A split pane appears on the left or top of the CFC workspace displaying the hierarchical technological tree.
Select and Edit the Root Control Module Node:
- In the Technological I/Os tree, select the root node representing the Control Module (this node displays the CMT icon and the current name containing (1)).
- Look at the 'Attributes' or 'Properties' pane below the tree.
- Locate the 'Name' attribute field.
- Delete the suffix (1) so that the name matches your intended plant tag (e.g., 1174MO241).
- Press Enter to apply the change.
- Save the CFC chart (Ctrl+S). The chart header and technological representation immediately update.

Method 2: Modification via SIMATIC Manager Plant View
1. Switch to Plant View:
- In SIMATIC Manager, select 'View > Plant View'.
- Navigate through the plant hierarchy to the folder containing the affected module.

Edit the Control Module Object:
- In the right-hand object list, locate the Control Module object (distinguished by the technological CMT icon, located alongside or beneath the CFC chart).
- Right-click the Control Module and select 'Object Properties' (or select it and press F2).
- In the 'General' tab, edit the 'Name' field to remove (1).
- Click 'OK'.

Method 3: Bulk Renaming in Process Object View (POV)
1. Open Process Object View:
- In SIMATIC Manager, select 'View > Process Object View'.
- Select the target plant hierarchy folder.
- Switch to the 'Control Modules' tab.
- In the 'Name' column, locate all instances exhibiting unwanted (1) suffixes.
- Edit the cells directly or copy-paste corrected names from an external spreadsheet.
- Save changes to apply technological renaming across multiple modules simultaneously.

Synchronize CMT and Recompile:
- If the CMT was altered in the Master Data Library, execute 'Options > 'Plant Types' > 'Synchronize...' to ensure instance consistency.
- Execute an OS compile ('Changes only') to update WinCC block icons and faceplate header tags.

Verification

Open the CFC chart in the CFC Editor: confirm that neither the chart window title bar nor the technological tree displays (1).
In SIMATIC Manager Plant View, verify that the hierarchy tree displays the clean name without numerical suffixes.
Perform an OS compile and launch WinCC Runtime (or use OS simulation).
Open the faceplate for the renamed module: confirm that the title bar, alarm text, and block icon display the exact technological name 1174MO241 without any trailing (1).

Limitations and Operational Precautions

Ensure that removing the suffix does not cause duplicate technological names within the same hierarchy level, as PCS 7 will reject duplicate names to preserve unique WinCC tag naming. Do not rename internal block pins or technological signal names unless corresponding adjustments are made in the Master Data Library CMT definition. For questions regarding engineering licenses and plant automation options, consult an authorized Siemens distributor or the Siemens Industry Mall.

Engineer FAQ

Why did renaming the CFC chart in Component View not update the faceplate name?

Renaming the CFC chart updates only the Step 7 file container. APL faceplates and WinCC block icons derive their display names from the 'Technological Name' inside the Control Module object.

Can I rename Control Modules while the CPU is in RUN mode?

Yes. Renaming technological attributes or CFC charts requires an AS program compile and download of changes, which executes in RUN mode without interrupting controller operation.

How can I rename dozens of Control Modules at once?

Use the Process Object View (POV) in SIMATIC Manager. Open the 'Control Modules' tab to bulk-edit technological names across entire plant hierarchy folders.

Why does PCS 7 automatically add (1) to newly copied charts?

PCS 7 enforces unique object names within each hierarchy folder to prevent database collisions during WinCC compilation and archiving.

What is the difference between CMT Name and CFC Name?

The CFC Name is the Step 7 chart container identifier; the CMT Name (Technological Name) is the functional asset identity recognized by APL faceplates, SFC types, and Batch systems.