How to Propagate Binary Alarms from FB43 MESSAGE into WinCC Area Button Group Displays in PCS 7

In SIMATIC PCS 7, alarms generated by custom binary message blocks like FB43 (MESSAGE) frequently appear in the WinCC alarm journal but fail to propagate upwards into the top-level Area navigation buttons in the WinCC overview area. This occurs because the block's event state tag is not linked to the picture's group display hierarchy. To resolve this, configure the FB43 instance with the 'OCM Possible' property in CFC, perform an OS compilation, place a Group Display object (@GroupDisplay) in the parent process graphic, connect it to the FB43 tag structure using the Dynamic Wizard 'Connect group display to PCS 7 tag structure', and save the Picture Tree Manager.

Group Display Alarm Propagation Architecture in SIMATIC PCS 7

In SIMATIC PCS 7 Basic Process Control (BPC), alarm awareness follows a strict hierarchical tree:
* The Alarm Hierarchy (Bottom to Top):
1. Block Level: Technological blocks (PIDConL, MotL, FB43) generate discrete alarms via ALARM_8P.
2. Picture Level: Every process graphic (.pdl) possesses an internal group state tag: @<PictureName>.
3. Area Button Level: The top-level screen header features navigation buttons corresponding to plant areas (e.g., Boiler, Turbine, Water Treatment).
4. The Group Display Icon: Area buttons display a 4-field or 5-field Group Display icon showing active, unacknowledged alarms for: Alarm High, Alarm Low, Warning High, Warning Low, and Operator Prompts.
* The Propagation Rule: An alarm at the block level must be formally bound to the picture's group display hierarchy for WinCC to bubble the alarm state up to the top-level area button.

Why FB43 MESSAGE Alarms Fail to Reach Area Buttons

When an engineer instantiates FB43 (MESSAGE) to monitor binary interlocks or custom PLC alarms:
* The Disconnect:
* FB43 generates message frames and updates its internal status parameter EventState (a 32-bit DWORD).
* Standard APL blocks (MonAnL, MotL) automatically generate block icons in the picture during OS compilation; these block icons contain internal group displays wired into @<PictureName>.
* Because FB43 does not generate an automatic block icon, its EventState remains isolated in WinCC Tag Management.
* The alarm is received by WinCC Alarm Logging and appears in the Alarm Journal, but @<PictureName> never registers the event, leaving the Area button completely dark!

Configuring OCM Properties on FB43 in Continuous Function Charts

To bring FB43 into the operator communication pipeline:

Enable Operator Control and Monitoring (OCM):
* In CFC, right-click the FB43 block: select Object Properties.
* Ensure that OCM possible is checked.
* Under the Messages configuration dialog, verify that message classes (e.g., Alarm High, Warning High) and message texts are defined.
Assign to Plant Hierarchy:
* Verify that the CFC chart hosting FB43 resides inside the plant hierarchy folder assigned to the target WinCC picture.
Execute OS Compilation:
* Compile the OS (Compile OS > Changes Only).
* WinCC Tag Management will now contain the tag: <Chart>\<FB43_Name>.EventState.

Connecting Picture Group Displays and Updating Picture Tree Manager

To bind FB43's EventState to the picture's collective group display:

Place Group Display in Graphics Designer:
* Open the target process graphic (e.g., Area1_Overview.pdl) in Graphics Designer.
* In the Object Palette, select the Smart Objects tab: drag a Group Display object onto the canvas.
Execute the Dynamic Wizard:
* While the Group Display is selected, open the Dynamic Wizard pane.
* Open the Picture Functions tab: double-click Connect group display to PCS 7 tag structure.
* In the wizard browser, select the FB43 instance tag structure (e.g., Area1/Unit1/CFC_Alarms/FB43_Instance).
* Click Finish. The wizard configures all internal tag links for EventState.
Save and Rebuild Picture Tree Manager:
* In WinCC Explorer, open Picture Tree Manager.
* Select Options > Recalculate complete group display hierarchy.
* Click Save. WinCC compiles the new group display links into the master @<PictureName> tags.

Comparison of Message Generating Blocks in SIMATIC PCS 7

The table below compares message generation blocks and their group display behavior.

Block NameBlock TypeBlock Icon Generated?Group Display PropagationBest ApplicationMonDiL (APL)Digital MonitorYes (Automatic)Automatic via Block IconStandard digital alarm monitoringFB43 (MESSAGE)System LibraryNoRequires manual Group DisplayCustom multi-channel binary messagesALARM_8P (SFB35)System FunctionNoManual programming requiredLow-level embedded block alarmsEventTS (APL)High-Precision SOENoAutomatic via APL hierarchySequence of events 1 ms time stamping

Verification

To confirm that FB43 alarms propagate to Area buttons:
1. In CFC, force an input condition on FB43 to trigger a high alarm.
2. Open WinCC Runtime on an OS Client: verify that the alarm appears in the top alarm banner.
3. Observe the plant navigation header: confirm that the Area Button corresponding to the picture highlights in red with a flashing Alarm High indicator.
4. Click the Area button to navigate to the picture: confirm that the embedded Group Display flashes red.
5. Acknowledge the alarm: confirm that the Area button transitions from flashing to steady red, and extinguishes completely when the condition clears.

Limitations and Operational Precautions

Never place FB43 in a hierarchy folder that has no associated WinCC picture; orphan charts cannot resolve the @<PictureName> tag hierarchy.
Whenever the plant hierarchy or picture assignments are modified, always execute 'Save' in Picture Tree Manager to regenerate group display compilation tables.
If deploying PCS 7 V8.0 or newer, prefer using the APL MonDiL block instead of legacy FB43; MonDiL integrates automatically with APL group displays without manual wizard steps.
Always validate final software licensing and system documentation against the applicable Siemens catalog and authorized distributor quotation.

Engineer FAQ

Why did the alarm show in the alarm banner but not on the Area button?

The alarm was successfully posted by ALARM_8P to the alarm logging database, but its EventState was not connected to a Group Display object inside the picture, leaving the parent @<PictureName> tag un-updated.

Can I hide the Group Display object on the screen?

Yes. You can set the Group Display object's Visible property to No in Graphics Designer; WinCC will still evaluate its internal tags and propagate the alarm state up to the Area button.

What does EventState contain?

EventState is a 32-bit DWORD where specific bits represent active alarm classes (Alarm High, Warning, Tolerance, Operator Request) and acknowledgment states for that block.