Restoring Missing Alarm Comments in WinCC Runtime and CEMAT Alarm Logging - AS-OS Engineering Version Alignment

When alarm comments fail to display across physical SIMATIC PCS 7 PC stations (Engineering Station, OS Servers, and OS Clients)—both in the WinCC runtime top single-line banner and in CEMAT Alarm Logging—despite functioning properly in development virtual machines, the root cause is typically a software hotfix disparity in AS-OS Engineering. In PCS 7 V8.2 with CEMAT, message attributes and block comments generated during OS compilation require AS-OS Engineering V8.2 Update 1. Installing AS-OS Engineering V8.2 Update 1 on the physical ES, followed by an Entire OS Compilation and project download, properly transfers comment attributes (S7_comment / OS_comment) into the WinCC Alarm Logging database. Additionally, verify in @AlarmNew.PDL that the 'Comment' message block is included in the displayed message line.

Root Causes of Missing Alarm Comments in CEMAT Systems

In industrial mineral and cement facilities using SIMATIC PCS 7 CEMAT (such as Holcim, Lafarge, or Heidelberg standards), operational alarms generated by drive blocks (C_DRV_1D, C_DRV_2D), damper blocks (C_DAMPER), and route blocks (C_ROUTE) rely on extensive message text configurations. Operators depend on the 'Comment' field in the WinCC alarm banner to identify specific field interlocks, drive MCC panel IDs, or process unit descriptions without opening detailed faceplates.

When a project functions perfectly in a virtualization environment (where comments render seamlessly) but shows blank comment fields when deployed to physical plant stations, engineers often suspect database corruption or operating system permissions. However, the Multiproject database itself is intact. The failure stems from a patch-level divergence between the development VM and the physical Engineering Station: specifically, base AS-OS Engineering V8.2 exhibited a known issue where block instance comments were dropped during message generation, a defect resolved in AS-OS Engineering V8.2 Update 1.

AS-OS Engineering Compilation and Database Transfer

The AS-OS Engineering package acts as the critical bridge between STEP 7 CFC charts and the WinCC Alarm Logging Microsoft SQL Server database. During an OS compile, it extracts message texts, alarm classes, priorities, and instance comments from the S7 block attributes.

Engineering LayerFunction in Message GenerationRequired Version / SettingCFC Block AttributesProvides S7_comment and S7_alarm_ui parametersConfigured in CFC block instance propertiesAS-OS Engineering CompilerTranslates CFC attributes into WinCC SQL Alarm TablesAS-OS Engineering V8.2 Update 1 (or later)WinCC Alarm LoggingStores static message texts and dynamic value definitionsSynchronized via OS Compilation wizardWinCC AlarmControl (@AlarmNew.PDL)Displays active and archived alarms in runtimeMessage Line property must include CommentCEMAT Alarm Logging ViewSpecialized cement industry alarm filteringReferences WinCC Alarm Logging standard tables

If the physical ES runs base AS-OS Engineering V8.2 without Update 1, recompiling the OS overwrites the WinCC SQL message tables with truncated records that omit comment bindings, causing all client stations to render empty fields.

Configuring WinCC AlarmControl Message Line Display

In addition to ensuring compiler patch parity, the WinCC Graphics Designer template for alarm displays must be configured to expose the comment column:

Open the Alarm Template: In WinCC Explorer, navigate to Graphics Designer and open @AlarmNew.PDL (or the custom CEMAT alarm picture @CEMAT_Alarm.PDL).
Open Control Properties: Double-click the WinCC AlarmControl object to open its configuration dialog.
Navigate to Message Line Tab: Select the Message Line or Message Blocks tab.
Add the Comment Column: In the available block list on the left, locate Comment. Use the > arrow button to move Comment into the active display column list on the right.
Adjust Column Ordering: Use the Up and Down buttons to position the Comment column adjacent to Message Text or Point of Error.
Save and Distribute: Save the PDL file. If running in a client-server architecture, ensure the modified template is saved in the OS Server GraCS directory or propagated via OS Project Duplicator.

Verification

Execute the following validation procedure to confirm that alarm comments appear correctly:

Software Version Audit: In SIMATIC Manager, select Help -> About -> Installed Software -> Display. Verify that AS-OS Engineering lists V8.2 Upd1 or higher on the physical ES.
Entire OS Compilation: In SIMATIC Manager, right-click the OS object, select Compile, choose Entire OS, and ensure Tags and Messages is selected.
Alarm Generation Test: In runtime, trigger a test trip or fault on a CEMAT drive block. Verify that the single-line alarm banner at the top of the screen displays the full descriptive comment alongside the alarm text.

Limitations and Operational Precautions

When patching AS-OS Engineering and recompiling alarms, observe the following operational rules:

Version Parity Across ES Stations: If multiple engineers collaborate across different physical laptops or VMs, all engineering stations must run identical PCS 7 updates to prevent oscillation of compiled message formats.
Full OS Download Required: After applying an AS-OS Engineering update and recompiling with changes in message structures, a complete OS download to the redundant server pair is necessary to update the SQL database schemas.
Language Alignment: Ensure that block comments entered in the CFC are populated in the active runtime language (e.g., English or German) configured in WinCC Text Distributor.

Engineer FAQ

Why did the project work in VMware but fail on the physical station?

The virtual machine had AS-OS Engineering V8.2 Update 1 installed, while the physical ES had base V8.2. Compiling on the physical ES stripped out the comment attributes because base V8.2 contained an unresolved compiler bug.

Can I restore missing comments without recompiling the entire OS?

No. The alarm message comments are compiled directly into the WinCC Alarm Logging Microsoft SQL database by AS-OS Engineering. Changes to message attributes require an OS compilation to populate the database tables.

Will updating AS-OS Engineering to Upd 1 require an AS CPU stop?

No. AS-OS Engineering is an engineering station component responsible for generating OS data. Updating it and recompiling the OS affects only WinCC and does not require stopping the S7-400 automation system CPUs.