Disabling Automatic Alarm Selection in TIA Portal WinCC HMI

Engineer field notes — Siemens TIA Portal WinCC alarm view auto-selection defect. This reference addresses a long-standing complaint against Siemens SIMATIC WinCC alarm views: the most recent alarm entering the buffer is always rendered with the row-selection background color, which on the default WinCC design is blue. Because the same row is also expected to carry the alarm class color (errors red, warnings yellow, etc.), the operator cannot tell at a glance which category the new event belongs to. No setting in the alarm view properties disables this behavior. The only viable remediation is to make the alarm class readable independently of the row background.

1. Problem Description

When a new alarm becomes active in WinCC, the runtime inserts the event into the alarm buffer and the Alarm view immediately focuses the new row. The row inherits the selection visual style, which by default replaces the entire cell background with a flat color (typically blue) defined in the active WinCC design.

For installations that rely on color to differentiate alarm classes — a common practice on Basic and Comfort Panels where the column width and screen real estate is limited — the auto-selection breaks the visual signal. Engineers report the same defect on KTP1200 Basic, TP700/TP1500 Comfort, and PC-based Runtime Advanced and Professional, from TIA Portal V13 SP1 all the way through V18.

2. Affected Products and Versions

For the latest firmware and image versions, see the Siemens Industry Online Support firmware download portal. For the SIMATIC HMI product family overview, see the SIMATIC HMI product page.

3. Root Cause Analysis

The Alarm view control in WinCC maintains an internal selected row pointer. The pointer is updated whenever a new row is appended to the buffer (event state comes in (C) or comes in / acknowledged (CA)). The pointer is also updated when the operator touches the row on a Panel.

The runtime paints the selected row with the AlarmView.SelectionColor style attribute, which the default WinCC design sets to a saturated blue. The class color is applied as a background fill of the cell, not as a border or foreground text, so when the selection color is drawn on top, the class color is no longer visible. There is no property DisableAutoSelect in the Alarm view configuration, and the WinCC engineering interface does not expose a way to decouple the row pointer update from the visual repaint.

4. Alarm View State Behavior

The diagram below summarizes the runtime state transitions that govern the visual style of a single row.

State diagram: row visual style transitions for a single alarm in a WinCC Alarm view. The only paths out of the blue-row state are operator interaction or buffer rollover.

5. Workaround 1 — Add an Alarm Class Column

The simplest fix is to make the alarm class a first-class field of the view so it remains visible even when the row is selected. Siemens WinCC alarm views support the Alarm Class column out of the box.

1. In the TIA Portal project tree, open the screen that contains the Alarm view.
2. Select the Alarm view object and open Properties > Columns in the Inspector window.
3. Click Add column and choose Alarm class from the dropdown. Confirm with OK.
4. Resize the new column to approximately 90–110 px on a TP700 / TP900 and 120–140 px on a TP1500 / TP2200. The icon-style variant is preferred on Unified Comfort Panels where the resolution is higher.
5. Compile the project and download to the Panel. Re-test with a simulated alarm source.

6. Workaround 2 — Customize the Selection Color to Match the Class

For projects that absolutely require a color-only signal, the runtime can be retuned to draw the selected row with a desaturated shade that approximates the class color. This is done through the Designs configuration in the WinCC Comfort / Advanced editor, or via a screen-level Style in WinCC Unified.

1. Open Project tree > Runtime settings > Design.
2. Duplicate the active design (do not modify the standard design — it is required by TIA for the offline/online comparison).
3. Open the duplicated design and navigate to Alarm view > Selection.
4. Set the Selection background to a color value with α ≈ 30 % (e.g. #3344AA66 in ARGB notation for a translucent blue that allows the underlying class color to bleed through).
5. Save, compile, and re-download.

For WinCC Unified Panels the design is replaced by a Style. Use the WinCC Unified Style Editor to bind the Alarm view's --alarmview-selection-background CSS variable to a translucent value:

An additional CSS rule can be added to make the alarm class color survive the selection as a thick left border, which is the pattern that works best on MTP1500 / MTP2200:

7. Workaround 3 — Stabilize Acknowledgment Acquisition

A related defect reported on the same installations is that the runtime does not always poll the PLC for the acknowledgement bit on the first scan. The workaround is to delay the reset of the alarm tag by 5 s in the PLC program so the Panel has time to re-read the bit. Implement the timer in the PLC and only release the trigger after the Panel has finished its first alarm update cycle.

Structured Text example (S7-1500 / S7-1200):

// Reset delayed by 5 seconds to give WinCC time to re-read ACK bit
#AlarmTrigger := FALSE;
IF #AckBit THEN
    #ResetTimer(IN := TRUE, PT := T#5s);
    IF #ResetTimer.Q THEN
        #AlarmTrigger := FALSE;
        #ResetTimer(IN := FALSE);
    END_IF;
END_IF;

8. Alarm View Configuration Parameters

9. Verification Procedure

1. Open the compiled HMI runtime on the target Panel (or in the TIA PLCSIM Advanced simulation).
2. Trigger a known Error-class alarm, then a known Warning-class alarm, then an Information-class alarm, in sequence.
3. Observe the Alarm view: the most recent row must remain blue, but the Alarm class column must clearly read "Error" / "Warning" / "Information".
4. Tap each row to clear the selection. The background must switch to the class color (red / yellow / green) within one refresh cycle (≤ 500 ms on Comfort Panels, ≤ 200 ms on Unified).
5. Acknowledge all three alarms. The row icon must transition to the "A" / "AR" state and the row must drop from the active filter.
6. Force a 5-second PLC reset delay (per Workaround 3) and re-run. Confirm the row remains visible long enough for the operator to tap it.
7. Force a fast PLC reset (no delay) and confirm that the "ghost clear" defect reproduces — this validates that the timer is doing its job.

10. Known Limitations and Vendor Response

As of TIA Portal V18, Siemens has not exposed a setting to disable the auto-selection of the most recent row. Engineering feedback has been collected under the WinCC Comfort / Advanced feedback channels, but no firmware update has been released that addresses the visual behavior. For projects that cannot tolerate the defect, the recommended path is to migrate to a SIMATIC Unified Comfort Panel running WinCC Unified, where the Alarm view is built on a modern web-stack and the selection style is fully styleable through CSS — including the option to set user-select: none on the row and drive the class color through a custom left-border rule that survives selection.

For documentation on configuring alarm views in WinCC, refer to the TIA Portal Help (F1 in the editor) under Visualize processes > Working with alarms > Configuring alarm views, and to the Siemens Industry Online Support knowledge base. For the SIMATIC HMI product family overview, see the SIMATIC HMI product page.

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