Configuring the Alarm Button on Faceplates in SIMATIC PCS 7 - Message Filtering and Loop-in-Alarm

Configuring the alarm button on a WinCC faceplate in SIMATIC PCS 7 (v6.0 classic library or modern APL) connects the faceplate toolbar button to the central alarm system via the block's EventState structure or message lock attributes. Clicking the alarm button executes a C-action or VBScript that passes the block's specific tag name into the WinCC Alarm Logging filter criteria, opening a filtered message list (Loop-in-Alarm) showing only alarms generated by that specific motor, valve, or analog instrument. In APL, this functionality is built-in, whereas legacy faceplates require configuring the @pl_*.pdl toolbar scripts.

PCS 7 Faceplate Alarm Architecture - Classic vs APL

In SIMATIC PCS 7, process alarms originate in the AS controller via message blocks (ALARM_8P / NOTIFY_8P) embedded inside driver and control blocks (such as MOT_L, VAL_L, MEAS_MON, or APL MotL). During OS Compilation, STEP 7 transfers message definitions to WinCC Alarm Logging.

When an operator investigates a fault from a graphic picture:
* Clicking a block icon opens the Faceplate (@pg_*.pdl or @pl_*.pdl).
* The faceplate toolbar contains an Alarm Button (bell icon).
* Clicking this button opens the Alarm View, which must dynamically filter the entire plant alarm list to show only alarms belonging to the selected technological block.

Configuring Loop-in-Alarm and Message View Filtering

The mechanism that links the faceplate button to the message display operates via WinCC internal scripts and tag attributes:
1. Classic Library (PCS 7 v6.x / v7.x):
* The alarm button in @pg_<type>.pdl triggers the C-function PCS7_OpenMsgWindow() or PCS7_DisplayAlarms().
* The script queries the faceplate property Tag (e.g. TIC101/MEAS_MON) and applies a SQL filter query: WHERE ProcessTag = 'TIC101/MEAS_MON'.
* If the button does not display alarms, the EventState structure tag connection or the MsgEv configuration in CFC was not compiled properly to the OS.
2. APL (Advanced Process Library - v7.1 and later):
* The alarm view is integrated as a dedicated tab (@pg_MotL_Alarm.pdl).
* The view binds automatically to the block's EventState and MsgLock tags without manual scripting.

Step-by-Step Faceplate Alarm Button Binding

To configure or restore the alarm button on custom or classic faceplates:

[Phase 1: Verify AS Block Configuration in CFC]
   │  • In CFC, open the technological block (e.g. MOTOR)
   │  • Right-click -> Object Properties -> Special Properties: "Messages..."
   │  • Confirm Message ID is assigned and "OCM possible" is enabled
   │
[Phase 2: Compile OS with Message Logging]
   │  • In SIMATIC Manager: Right-click OS -> "Compile"
   │  • Ensure scope includes: "Tags and messages"
   │  • OS compile registers block tags into WinCC Alarm Logging
   │
[Phase 3: Connect WinCC Faceplate Alarm Button in Graphics Designer]
   │  • Open the faceplate view (@pg_<CustomBlock>.pdl) in WinCC Graphics Designer
   │  • Select the Alarm Toolbar Button -> Events -> Mouse Action
   │  • Link the script to standard PCS 7 message handler:
   │      PCS7_OpenAlarmWindow(lpszPictureName, lpszObjectName);
   │  • Connect the Faceplate's "CollectValue" property to the block's ".EventState"

Alarm Integration Comparison - Classic Standard Library vs APL

Compare the engineering requirements across PCS 7 library generations:

Architectural FeatureClassic Standard Library (v6.x / v7.x)Advanced Process Library (APL v7.1 - v9.x)Alarm View ArchitectureExternal popup window (@alarmview.pdl)Embedded faceplate tab (@pg_*_Alarm.pdl)Scripting MechanismANSI-C scripts (PCS7_OpenMsgWindow)Standardized APL Faceplate ActiveX ControlFilter AssociationTag name matching via SQL text queryAutomatic binding to structure tag prefixAlarm Suppression SupportBasic message lock (MsgLock)Multi-level suppression (MsgLock, MsgSup, OosOp)Loop-in-Alarm NavigationConfigured via WinCC Alarm Logging hookFully automated bidirectional navigation

Verification

To confirm that the faceplate alarm button functions correctly:
1. In WinCC Runtime, open the process graphic containing the motor or valve block icon.
2. Force an alarm condition in CFC (e.g. simulation of feedback error or trip).
3. Verify that the block icon displays a flashing red alarm badge.
4. Click the block icon to open the faceplate; verify that the alarm button (bell) is active and indicates an active alarm.
5. Click the alarm button; verify that the alarm message window opens immediately, displaying strictly the alarm records associated with that specific block.

Limitations and Operational Precautions

Never modify default Siemens template pictures (@*.pdl) directly in the installation directory. If customizing classic faceplates, always copy the @pg_*.pdl file to the individual WinCC project GraCS folder before editing. Overwriting master templates can corrupt faceplate behavior across the entire engineering station. Ensure EventState structure tags are never renamed manually in the WinCC Tag Management table.

Engineer FAQ

Why is the alarm button grayed out on my custom faceplate?

The alarm button disables automatically if the block has no EventState tag connected, or if no messages were defined for that block in CFC prior to OS compilation.

What does 'Loop-in-Alarm' mean in PCS 7?

Loop-in-Alarm allows an operator viewing an alarm list to click a button that instantly navigates to the process graphic containing the faulted equipment and opens its faceplate.

Can I filter the alarm window to show both motor and interlock alarms?

Yes. By assigning identical technological area or hierarchy path filters in the message query, the alarm window displays alarms from all related sub-blocks.

How does APL handle alarm silencing from the faceplate?

APL provides the MsgLock input in CFC and an operator lock button on the faceplate alarm tab, allowing authorized operators to suppress nuisance alarms locally.