Configuring and Understanding Message Suffix Generation in SIMATIC PCS 7 WinCC

In SIMATIC PCS 7 WinCC Alarm Logging, message text suffixes are not an automated system default, but are generated by configuring user text blocks or appending technological attributes during CFC compilation. Engineers implement message suffixes by renaming a free user text block to 'Suffix' in Alarm Logging, mapping technological hierarchy paths via block attributes ($$BlockComment$$), or dynamically passing string variables into associated process values.

Architecture of Message Text Synthesis in SIMATIC PCS 7

In SIMATIC PCS 7 process control systems, alarm messages displayed in the WinCC runtime alarm list are synthesized automatically during AS-OS compilation:
* The AS Layer (CFC): Technological blocks (MotL, VlvL, PIDConL, MonAnL) instantiate the system message block ALARM_8P (FB19).
* The OS Layer (WinCC Alarm Logging): The compiler reads block attributes, plant hierarchy structures, and message configuration tables, populating the WinCC message dictionary.
* When inspecting an operational alarm table, engineers frequently observe a "Suffix" column detailing specific operating units, failure modes, or equipment descriptions (e.g., Feed Pump 101 - Overload Trip - High Priority), and ask how this suffix is generated and controlled.

Deconstructing the Message Block: ALARM_8P User Text Columns

In WinCC Alarm Logging, every message line is composed of standardized system blocks and customizable user text blocks:
* System Text Blocks: Date, Time, Priority, Status, State, Acknowledgment State.
* User Text Blocks: WinCC provides 10 customizable user text columns:
* User Text 1: Typically allocated to Message Text (e.g., Overload Trip).
* User Text 2: Typically allocated to Point of Error / Location (e.g., MCC-01).
* User Text 3 to 10: Free user text blocks available for engineering customization.
* In standard PCS 7 projects, there is no hardcoded column named "Suffix". Rather, system integrators configure one of the free user text blocks (e.g., User Text 3), rename its column header to "Suffix", and map it to block parameters.

Method 1: Customizing User Text Blocks as a Dedicated Suffix Field

To configure a dedicated Suffix column across the WinCC message system:
1. Open WinCC Explorer -> Alarm Logging.
2. In the navigation tree, select Message Blocks -> User Text Blocks.
3. Select an unused text block (e.g., User Text 3 or User Text 4).
4. In Object Properties, change the name to Suffix.
5. Set the maximum character length (e.g., 32 or 64 characters).
6. Open WinCC AlarmControl in Graphics Designer (@alarm.pdl):
* Select the Message List tab.
* Under Message Blocks, move Suffix from the Available Blocks list to the Selected Blocks list.
* Adjust its column position and width.

Method 2: Automated CFC Attribute Propagation ($$BlockComment$$ / TH Paths)

To populate the Suffix automatically from controller logic without manual typing in WinCC:
1. Technological Hierarchy (TH) Propagation:
* In SIMATIC Manager, select Options -> Plant Hierarchy -> Customize....
* Configure the OS message text generation rules to automatically concatenate plant hierarchy folder names into message parameters.
2. Block Comment Concatenation:
* In the CFC block message configuration dialog, use the system macro $$BlockComment$$.
* When compiled, the compiler automatically substitutes the text entered in the CFC block's comment field (e.g., "Emergency Discharge Valve") into the designated message text block.
3. Dynamic Associated Values:
* Pass dynamic string tags into associated values (SD_1 to SD_10), using placeholders like @1W%s@ to inject runtime text strings into the suffix field.

Verification

In SIMATIC Manager, modify the comment field on a test MonDiL block in CFC to "High-Pressure Suffix Test".
Execute an AS-OS compilation (Changes Only).
In WinCC OS runtime, trigger an alarm from the test block.
Verify that the active alarm row displays the full message text, and that the Suffix column correctly renders "High-Pressure Suffix Test".
Sort the alarm list by the Suffix column: verify that messages group logically by operational suffix.

Limitations and Operational Precautions

Renaming user text blocks in Alarm Logging alters the database schema; perform complete OS compiles across all redundant servers to maintain database synchronization.
Avoid allocating excessive character lengths (> 128 characters) to multiple user text blocks, as large message payloads increase SQL transaction log sizes.
Never hardcode multilingual suffixes in static CFC comments; use Text Libraries (%t#) if the plant operates in multiple languages.

Engineer FAQ

Is there an automated default column named 'Suffix' in PCS 7 Alarm Logging?
No, Suffix is a customized user text block renamed in WinCC Alarm Logging to meet project specifications.
How many customizable User Text Blocks does WinCC Alarm Logging provide?
WinCC provides 10 independent User Text Blocks per message.
What CFC macro inserts the block comment into message texts automatically?
The macro $$BlockComment$$ copies the CFC block comment into the message configuration.
Where is the column header name changed from 'User Text' to 'Suffix'?
In WinCC Alarm Logging under Message Blocks -> User Text Blocks in the block properties dialog.
Can dynamic runtime strings be used as message suffixes?
Yes, by passing string variables into ALARM_8P associated values and referencing them via @<n>W%s@.
Why did the Suffix column disappear after running OS Project Editor?
Running OS Project Editor with complete update restores default column profiles; re-apply custom column layouts in AlarmControl.
Can I sort and filter alarms by the Suffix column in runtime?
Yes, WinCC AlarmControl allows operators to sort, group, and filter by any active user text column.
Does customizing user text blocks consume additional AS Process Objects?
No, user text formatting is an OS database configuration that consumes zero additional process objects.
What S7 block in the controller generates the alarm data for WinCC?
The system function block ALARM_8P (FB19) instantiated inside technological blocks.
How do I ensure suffix text displays correctly in both English and German?
Use user Text Libraries referenced via @<n>W%t#LibraryName@ instead of static ASCII strings.

Technical References

SIMATIC HMI WinCC V7.5 Alarm Logging System Manual
SIMATIC PCS 7 Engineering System Configuration Manual (Message Configuration)
Siemens Industry Online Support Entry: Suffix and User Text Blocks in PCS 7 (Entry ID 299842)
SIMATIC STEP 7 V5.6 System Software for S7-300/400 System and Standard Functions