Customizing Alarm Logging Column Headers and Message Blocks in WinCC and PCS 7

To customize column names such as User Text block 1 in the WinCC Alarm Control without risking overwrite during OS-Project Editor execution, edit the column header in the WinCC Alarm Logging editor and the Text Library. Open WinCC Explorer, launch Alarm Logging, navigate to Message Blocks, select the target user text block, and modify its properties. Then update the assigned Text ID across all project languages in the Text Library to ensure persistence across OS compilations.

Structure of Message Blocks in WinCC Alarm Logging

In SIMATIC PCS 7 and WinCC SCADA systems, the Alarm Logging runtime display (WinCC AlarmControl) organizes process messages using structured Message Blocks. These blocks fall into three distinct functional categories:
1. System Blocks: Fixed system attributes such as Date, Time, Priority, Class, Type, Status, and Event State.
2. User Text Blocks: Customizable alphanumeric fields typically assigned to block parameters such as Message Text, Fault Location, Plant Section, and custom annotations (e.g., User Text block 1 through User Text block 10).
3. Process Value Blocks: Dynamic numerical or string values captured at the moment the alarm triggered (such as process temperature, tank level, or motor current passed via ALARM_8P associated values).

Engineers frequently need to customize column header labels (e.g., renaming User Text block 1 to Source text or Equipment Tag). However, modifying the text label directly on the WinCC Alarm Control ActiveX/.NET object in Graphics Designer (@AlarmControl.pdl or @Overview1.pdl) is dangerous: running the mandatory PCS 7 OS-Project Editor tool will restore standard Siemens delivery templates and overwrite manual screen edits.

Message Block Architecture Comparison Table

Understanding how message block types map between engineering data, runtime storage, and visualization ensures consistent multilingual operation:

Message Block CategoryDefault PCS 7 AssignmentModifiability in Alarm LoggingMultilingual Support MechanismRisk of OS-Project Editor OverwriteSystem Block: Date/TimeChronological event timestampFormat modifiable; Header fixedSystem localized via Windows OS Regional SettingsZero risk; maintained in WinCC coreSystem Block: Class/TypeAlarm class (Alarm, Warning, Tolerance)Color, name, and priority customizableText Library entries tied to Class/Type IDsPreserved if edited in Alarm Logging editorUser Text Block 1Origin / Plant Hierarchy pathFully customizable column titleWinCC Text Library via unique Text IDOverwritten if changed in PDL; Safe via Text LibraryUser Text Block 2Event description / Message textFully customizable column titleWinCC Text Library via unique Text IDOverwritten if changed in PDL; Safe via Text LibraryProcess Value Block 1-10Analog snapshot values (e.g., PV)Display format and header customizableLocalized column header in Alarm LoggingSafe when configured via central Message Blocks

Engineering notice: When deploying custom message block headers in multi-client architectures, compile the OS server and download server data packages to all OS clients.

Configuring Custom Column Headers via Alarm Logging and Text Library

Follow this procedure to configure persistent, multilingual column headers:

Access Alarm Logging Message Blocks:
* Open the target OS project in WinCC Explorer.
* Open the Alarm Logging editor.
* In the navigation tree on the left, expand Message Blocks.
* Select User Text Blocks (or System Blocks depending on the column).
Inspect and Modify Block Properties:
* In the detail view, right-click the target block (e.g., User Text block 1) and select Properties.
* Locate the field Message block name and enter the desired default identifier (e.g., Source text).
* Observe the assigned Text ID number generated by the system.
Update Multilingual Text Library:
* Return to WinCC Explorer and open the Text Library editor.
* Filter or search by the Text ID recorded from the message block properties.
* Edit the text string in each installed language column (e.g., English: Source text, German: Quelltext, French: Texte source).
* Save and close the Text Library.
Configure WinCC AlarmControl Column Assignment:
* Open Graphics Designer and open the process screen containing the WinCC AlarmControl (e.g., @AlarmControl.pdl or a custom screen).
* Double-click the AlarmControl to open its configuration dialog.
* Navigate to the Message Blocks tab. Ensure the renamed block is added to the Selected Message Blocks list.
* Under the Columns tab, verify that the column header displays the Text Library string.

Protecting Custom Alarm Configurations Against OS-Project Editor Overwrites

The OS-Project Editor re-creates standard PCS 7 layout pictures whenever basic data updates occur. To protect custom column selections:
1. In the OS-Project Editor configuration dialog, select the Basic Data tab.
2. Review the list of managed screen files. If @AlarmControl.pdl is marked with a red symbol or checkmark, the editor will overwrite it with the catalog version during generation.
3. To retain custom column arrangements permanently, do not uncheck @AlarmControl.pdl (which would prevent necessary system hotfixes). Instead, ensure all column name definitions reside within the Alarm Logging database and Text Library. Because OS-Project Editor only replaces graphic files and not project database entries, the newly generated @AlarmControl.pdl will automatically query the Alarm Logging editor and display your custom column titles upon opening.

Verification

Verify column customization through the following tests:
1. Activate WinCC Runtime on the OS station.
2. Open the alarm logging view. The column header previously labeled User Text block 1 must display Source text.
3. Switch runtime language (e.g., from English to German) using the language switch control; verify that the header dynamically changes to the translated text.
4. Run OS-Project Editor on the engineering station, recompile the OS, and verify that the custom column names persist without reverting.

Limitations and Operational Precautions

Do not change the fundamental data width of User Text blocks after commissioning large historical archives, as resizing fields from 16 to 128 characters can trigger database schema re-indexing and transient CPU spikes on the OS Server.
In PCS 7 systems with redundant OS Servers, always perform changes on the Engineering Station and download to both OS Servers to avoid text library desynchronization.
Modifying System Block headers must be done with care to prevent confusion regarding standard PCS 7 alarm priorities and timestamp formats.

Engineer FAQ

Why can't I edit the column header directly inside the WinCC AlarmControl properties dialog?

While WinCC AlarmControl allows local override of column titles in individual graphic pictures, doing so decouples the display from the centralized Text Library. In PCS 7, this causes language switching to fail and results in loss of modifications during OS compilation.