Suppressing Asset Management Diagnostic Alarms in WinCC OS Without Modifying PCS 7 Projects

In SIMATIC PCS 7 operations, suppressing Asset Management System (Maintenance Station) diagnostic alarms on WinCC OS servers and clients—without altering the diagnostic hierarchy or recompiling the engineering project—is accomplished by applying runtime message filters in the WinCC AlarmControl. By filtering out the diagnostic message class (System Message, Requires Acknowledgment) or using WinCC Smart Alarm Hiding, operators eliminate nuisance diagnostic alarms while preserving full maintenance station functionality.

Role of the Maintenance Station (AMS) in SIMATIC PCS 7 Diagnostics

The SIMATIC PCS 7 Maintenance Station (MS) provides plant asset management according to NAMUR NE107 guidelines:
* It monitors the health of field instruments (HART, PROFIBUS PA, PROFINET), automation stations (CPUs, power supplies), network switches (SCALANCE), and PC stations.
* Diagnostic Alarms: When a communication discrepancy or redundant power supply fault occurs, system diagnostic drivers (MOD_x, OB_BEGIN) generate diagnostic messages categorized under standard system message classes.
* When a facility chooses not to monitor specific asset discrepancies (e.g., redundant signal discrepancies on uncommissioned channels), these diagnostic alarms appear continuously in the operator alarm banner, cluttering operational views.

Mechanism of Diagnostic Alarm Generation Across the Plant Bus

Removing the diagnostic hierarchy in SIMATIC Manager deletes the entire asset management database, which plant management frequently rejects:
* Deleting the diagnostic structure disables hardware health monitoring across all automation stations.
* In contrast, the requirement is often strictly visual: suppress the diagnostic messages from operator screens without touching the CFC charts, AS program, or Asset Management System configuration.
* Because all WinCC alarms are filtered dynamically before display, visual suppression can be achieved entirely at the WinCC OS runtime layer.

Method 1: WinCC AlarmControl Runtime Message Class Filtering

To exclude diagnostic alarms from the main operational alarm list:
1. Open Graphics Designer on the Engineering Station (or modify the screen locally on the OS Server).
2. Open the main alarm display picture: @alarm.pdl (or custom process alarm displays).
3. Double-click the WinCC AlarmControl object to open its Properties.
4. Select the Message List tab.
5. In the Selection section, click Edit... to open the SQL Filter criteria builder.
6. Configure the filter condition:
* Select criterion: Class / Message Class.
* Operator: Not Equal to (<>).
* Value: Select the diagnostic message classes (e.g., System, without acknowledgment, System, with acknowledgment, or specific Asset Management diagnostic classes).
7. Save the picture. When operators view the alarm list, diagnostic alarms are hidden from operational view while remaining accessible on dedicated maintenance displays.

Method 2: Smart Alarm Hiding and Message Suppression

If specific diagnostic messages must be suppressed dynamically:
1. Manual Alarm Hiding:
* In WinCC runtime, select the unwanted diagnostic alarm in the alarm banner.
* Click the Hide Message button on the AlarmControl toolbar.
* The message is removed from the active operational list and routed to the Hidden Messages list.
2. Permanent Suppression via Alarm Logging:
* Open WinCC Explorer -> Alarm Logging.
* Locate the specific system diagnostic message number (e.g., Event ID 16#...).
* In message properties, uncheck the box Visible or assign it to an unmonitored message class.
* This deactivates display without modifying the AS or deleting the diagnostic hierarchy.

Verification

In WinCC OS runtime, verify that the operational alarm banner displays only technological process alarms (temperatures, pressures, motor trips).
Confirm that system diagnostic alarms no longer trigger audible horns or visual red alarm banners on operator workstations.
Open the dedicated Maintenance Station view (@Maintenance.pdl): confirm that hardware diagnostic icons still show device status, proving asset monitoring remains fully active in the background.

Limitations and Operational Precautions

Filtering system messages from the operator alarm list prevents operators from seeing hardware faults (e.g., power supply failure or fiber-optic ring break); ensure maintenance personnel monitor dedicated Maintenance Station screens.
Modifying system screens (@alarm.pdl) directly in GraCS can be overwritten if the WinCC OS Project Editor is executed with "Update completely"; save custom filters in template configurations.
Always document alarm suppression in plant alarm management audit logs to comply with ISA-18.2 standards.

Engineer FAQ

What message class do PCS 7 diagnostic alarms typically belong to?
They belong to 'System, with acknowledgment' or dedicated 'Maintenance' classes under NAMUR NE107.
Can I remove diagnostic alarms without deleting the diagnostic hierarchy in CFC?
Yes, by configuring SQL message class filters or hiding alarms in the WinCC AlarmControl properties.
What system screen hosts the main WinCC alarm display?
The picture @alarm.pdl located in the WinCC project GraCS folder.
Does suppressing alarms in WinCC affect the physical controllers?
No, WinCC alarm filtering is purely visual and does not alter controller logic or execution.
How do I view hidden diagnostic alarms if needed for troubleshooting?
Open the Hidden Messages tab or maintenance alarm screen in WinCC AlarmControl.
Can I filter out alarms originating from specific redundant hardware?
Yes, by filtering on the specific tag prefix or hardware module diagnostic address in the filter builder.
What standard governs smart alarm hiding in process automation?
The ISA-18.2 standard (Management of Alarm Systems for the Process Industries).
Does filtering diagnostic messages prevent them from being logged to the database?
No, filtered alarms continue to be archived in the WinCC SQL message database for historical auditing.
What happens to custom @alarm.pdl modifications when running OS Project Editor?
They can be overwritten unless backed up or configured as project-specific templates.
Is an AS download required to apply WinCC AlarmControl filters?
No, modifying WinCC graphic pictures requires only saving the PDL and downloading changes to the OS.

Technical References

SIMATIC PCS 7 Maintenance Station Operating Manual
SIMATIC HMI WinCC V7.5 Alarm Logging System Manual
Siemens Industry Online Support Entry: Filtering Diagnostic Alarms in WinCC (Entry ID 299770)
NAMUR NE107 Diagnostic Alarm Classification Standard